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Xuan M, Wang W, Bulloch G, Zhang J, Ha J, Wang Q, Wang J, Lin X, He M. Impact of Acute Ocular Hypertension on Retinal Ganglion Cell Loss in Mice. Transl Vis Sci Technol 2024; 13:17. [PMID: 38506800 PMCID: PMC10959197 DOI: 10.1167/tvst.13.3.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 02/07/2024] [Indexed: 03/21/2024] Open
Abstract
Purpose To assess the correlation between intraocular pressure (IOP) levels and retinal ganglion cell (RGC) loss across different fixed-duration episodes of acute ocular hypertension (AOH). Methods AOH was induced in Thy1-YFP-H transgenic mice by inserting a needle connected to a saline solution container into the anterior chamber. Thirty-one groups were tested, each comprising three to five mice exposed to IOP levels ranging from 50 to 110 mm Hg in 5/10 mm Hg increments for 60/90/120 minutes and a sham control group. The YFP-expressing RGCs were quantified by confocal scanning laser ophthalmoscopy, whereas peripapillary ganglion cell complex thickness was measured using spectral-domain optical coherence tomography. Changes in RGC count and GCCT were determined from values measured 30 days after AOH relative to baseline (before AOH). Results In the 60-minute AOH groups, RGC loss varied even when IOP was increased up to 110 mm Hg (36.8%-68.2%). However, for longer durations (90 and 120 minutes), a narrow range of IOP levels (60-70 mm Hg for 90-minute duration; 55-65 mm Hg for 120-minute duration) produced a significant difference in RGC loss, ranging from <25% to >90%. Additionally, loss of YFP-expressing RGCs was comparable to that of total RGCs in the same retinas. Conclusions Reproducible RGC loss during AOH depends on precise durations and IOP thresholds. In the current study, the optimal choice is an AOH protocol set at 70 mm Hg for a duration of 90 minutes. Translational Relevance This study can assist in determining the optimal duration and intensity of IOP for the effective utilization of AOH models.
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Affiliation(s)
- Meng Xuan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Wei Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Gabriella Bulloch
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
- Faculty of Science, Medicine and Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Jian Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Jason Ha
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia
| | - Qilin Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Juanjuan Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Xingyan Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
| | - Mingguang He
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, Guangdong, China
- School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- Centre for Eye and Vision Research (CEVR), Hong Kong, China
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Yang F, Almasieh M, Levin LA. In Vivo Imaging of Secondary Neurodegeneration Associated With Phosphatidylserine Externalization Along Axotomized Axons. Invest Ophthalmol Vis Sci 2024; 65:24. [PMID: 38345553 PMCID: PMC10866172 DOI: 10.1167/iovs.65.2.24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 12/11/2023] [Indexed: 02/15/2024] Open
Abstract
Purpose Axonal degeneration in acute and chronic disorders is well-characterized, comprising retrograde (proximal) and Wallerian (distal) degeneration, but the mechanism of propagation remains less understood. Methods Laser injury with a diode-pumped solid-state 532 nm laser was used to axotomize retinal ganglion cell axons. We used confocal in vivo imaging to demonstrate that phosphatidylserine externalization is a biomarker of early axonal degeneration after selective intraretinal axotomy. Results Quantitative dynamic analysis revealed that the rate of axonal degeneration was fastest within 40 minutes, then decreased exponentially afterwards. Axonal degeneration was constrained within the same axotomized axonal bundles. Remarkably, axon degeneration arising from the site of injury induced a secondary degeneration of distal normal axons. Conclusions Axonal degeneration in vivo is a progressive process associated with phosphatidylserine externalization, which can propagate not only along the axon but to adjacent uninjured axons. This finding has implications for acute and chronic neurodegenerative disorders associated with axonal injury.
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Affiliation(s)
- Fan Yang
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada
| | - Mohammadali Almasieh
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada
| | - Leonard A. Levin
- Department of Ophthalmology and Visual Sciences, McGill University, Montreal, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, Canada
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Ma D, Deng W, Khera Z, Sajitha TA, Wang X, Wollstein G, Schuman JS, Lee S, Shi H, Ju MJ, Matsubara J, Beg MF, Sarunic M, Sappington RM, Chan KC. Early inner plexiform layer thinning and retinal nerve fiber layer thickening in excitotoxic retinal injury using deep learning-assisted optical coherence tomography. Acta Neuropathol Commun 2024; 12:19. [PMID: 38303097 PMCID: PMC10835918 DOI: 10.1186/s40478-024-01732-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 01/14/2024] [Indexed: 02/03/2024] Open
Abstract
Excitotoxicity from the impairment of glutamate uptake constitutes an important mechanism in neurodegenerative diseases such as Alzheimer's, multiple sclerosis, and Parkinson's disease. Within the eye, excitotoxicity is thought to play a critical role in retinal ganglion cell death in glaucoma, diabetic retinopathy, retinal ischemia, and optic nerve injury, yet how excitotoxic injury impacts different retinal layers is not well understood. Here, we investigated the longitudinal effects of N-methyl-D-aspartate (NMDA)-induced excitotoxic retinal injury in a rat model using deep learning-assisted retinal layer thickness estimation. Before and after unilateral intravitreal NMDA injection in nine adult Long Evans rats, spectral-domain optical coherence tomography (OCT) was used to acquire volumetric retinal images in both eyes over 4 weeks. Ten retinal layers were automatically segmented from the OCT data using our deep learning-based algorithm. Retinal degeneration was evaluated using layer-specific retinal thickness changes at each time point (before, and at 3, 7, and 28 days after NMDA injection). Within the inner retina, our OCT results showed that retinal thinning occurred first in the inner plexiform layer at 3 days after NMDA injection, followed by the inner nuclear layer at 7 days post-injury. In contrast, the retinal nerve fiber layer exhibited an initial thickening 3 days after NMDA injection, followed by normalization and thinning up to 4 weeks post-injury. Our results demonstrated the pathological cascades of NMDA-induced neurotoxicity across different layers of the retina. The early inner plexiform layer thinning suggests early dendritic shrinkage, whereas the initial retinal nerve fiber layer thickening before subsequent normalization and thinning indicates early inflammation before axonal loss and cell death. These findings implicate the inner plexiform layer as an early imaging biomarker of excitotoxic retinal degeneration, whereas caution is warranted when interpreting the ganglion cell complex combining retinal nerve fiber layer, ganglion cell layer, and inner plexiform layer thicknesses in conventional OCT measures. Deep learning-assisted retinal layer segmentation and longitudinal OCT monitoring can help evaluate the different phases of retinal layer damage upon excitotoxicity.
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Affiliation(s)
- Da Ma
- Wake Forest University School of Medicine, 1 Medical Center Blvd, Winston-Salem, NC, 27157, USA.
- Wake Forest University Health Sciences, Winston-Salem, NC, USA.
- Translational Eye and Vision Research Center, Wake Forest University School of Medicine, Winston-Salem, NC, USA.
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada.
| | - Wenyu Deng
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA
- Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - Zain Khera
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA
| | - Thajunnisa A Sajitha
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA
| | - Xinlei Wang
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA
| | - Gadi Wollstein
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA
- Center for Neural Science, College of Arts and Science, New York University, New York, NY, USA
- Department of Biomedical Engineering, Tandon School of Engineering, New York University, Brooklyn, NY, USA
| | - Joel S Schuman
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA
- Center for Neural Science, College of Arts and Science, New York University, New York, NY, USA
- Department of Biomedical Engineering, Tandon School of Engineering, New York University, Brooklyn, NY, USA
- Wills Eye Hospital, Philadelphia, PA, USA
- Department of Biomedical Engineering, Drexel University, Philadelphia, PA, USA
- Neuroscience Institute, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA
| | - Sieun Lee
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
- Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, BC, Canada
- Mental Health and Clinical Neurosciences, School of Medicine, University of Nottingham, Nottingham, UK
| | - Haolun Shi
- Department of Statistics and Actuarial Science, Simon Fraser University, Burnaby, BC, Canada
| | - Myeong Jin Ju
- Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, BC, Canada
| | - Joanne Matsubara
- Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, BC, Canada
| | - Mirza Faisal Beg
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Marinko Sarunic
- Institute of Ophthalmology, University College London, London, UK
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Rebecca M Sappington
- Wake Forest University School of Medicine, 1 Medical Center Blvd, Winston-Salem, NC, 27157, USA
- Wake Forest University Health Sciences, Winston-Salem, NC, USA
- Translational Eye and Vision Research Center, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Kevin C Chan
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA.
- Center for Neural Science, College of Arts and Science, New York University, New York, NY, USA.
- Department of Biomedical Engineering, Tandon School of Engineering, New York University, Brooklyn, NY, USA.
- Neuroscience Institute, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA.
- Department of Radiology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA.
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Qian Z, Zheng K, Xu Y, Chen S, Chen S, Liang J, Cao Y, Ng TK, Qiu K. Longitudinal in vivo evaluation of retinal ganglion cell complex layer and dendrites in mice with experimental autoimmune encephalomyelitis. Exp Eye Res 2023; 237:109708. [PMID: 37913917 DOI: 10.1016/j.exer.2023.109708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/24/2023] [Accepted: 10/28/2023] [Indexed: 11/03/2023]
Abstract
Experimental autoimmune encephalomyelitis (EAE), induced by the immunization of myelin oligodendrocyte glycoprotein (MOG), is related to human MOG antibody-associated disease (MOGAD). Neuroinflammation and demyelination of the optic nerve can lead to retinal ganglion cell (RGC) death and axonal damage in MOGAD. Here, we aimed to evaluate the structural changes in RGCs longitudinally by in vivo imaging in mice with RGCs expressing yellow fluorescent protein along the course of EAE. Successful induction of EAE was confirmed by the neurological function scores and histology analyses. The changes in the thickness of ganglion cell complex (GCC) layer and RGC survival and dendrites were monitored longitudinally along the course of EAE. Before the onset of EAE, there were no significant changes in the number and morphology of RGCs and the thickness of the GCC layer as compared to the mice without EAE induction. After the onset of EAE, the thickness of the GCC layer and the RGC number and dendritic network all gradually decreased along the course of EAE. Notably, dendritic shrinkage could be detected earlier than the thinning of the GCC layer. In summary, this study delineated the longitudinal profile of RGC structural changes in EAE mice, providing an assessment platform for monitoring outcomes of RGC treatments.
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Affiliation(s)
- Zhen Qian
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China; Shantou University Medical College, Shantou, Guangdong, China
| | - Ke Zheng
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China; Shantou University Medical College, Shantou, Guangdong, China
| | - Yanxuan Xu
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Si Chen
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Shaowan Chen
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Jiajian Liang
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Yingjie Cao
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China
| | - Tsz Kin Ng
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China; Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong.
| | - Kunliang Qiu
- Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China.
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Zhang P, Vafaeva O, Dolf C, Ma Y, Wang G, Cho J, Chan HHL, Marsh-Armstrong N, Zawadzki RJ. Evaluating the performance of OCT in assessing static and potential dynamic properties of the retinal ganglion cells and nerve fiber bundles in the living mouse eye. BIOMEDICAL OPTICS EXPRESS 2023; 14:6422-6441. [PMID: 38420317 PMCID: PMC10898556 DOI: 10.1364/boe.504637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/08/2023] [Accepted: 11/11/2023] [Indexed: 03/02/2024]
Abstract
Glaucoma is a group of eye diseases characterized by the thinning of the retinal nerve fiber layer (RNFL), which is primarily caused by the progressive death of retinal ganglion cells (RGCs). Precise monitoring of these changes at a cellular resolution in living eyes is significant for glaucoma research. In this study, we aimed to assess the effectiveness of temporal speckle averaging optical coherence tomography (TSA-OCT) and dynamic OCT (dOCT) in examining the static and potential dynamic properties of RGCs and RNFL in living mouse eyes. We evaluated parameters such as RNFL thickness and possible dynamics, as well as compared the ganglion cell layer (GCL) soma density obtained from in vivo OCT, fluorescence scanning laser ophthalmoscopy (SLO), and ex vivo histology.
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Affiliation(s)
- Pengfei Zhang
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, 116024, China
- UC Davis EyePod Small Animals Ocular Imaging Laboratory, University of California Davis, Davis, CA 95616, USA
| | - Olga Vafaeva
- Department of Ophthalmology & Vision Science, University of California Davis Eye Center, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
| | - Christian Dolf
- Department of Ophthalmology & Vision Science, University of California Davis Eye Center, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
| | - Yanhong Ma
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, 116024, China
| | - Guozhen Wang
- School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, 116024, China
| | - Jessicca Cho
- UC Davis EyePod Small Animals Ocular Imaging Laboratory, University of California Davis, Davis, CA 95616, USA
| | - Henry Ho-Lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
- Research Centre for SHARP Vision (RCSV), The Hong Kong Polytechnic University, Hong Kong, China
| | - Nicholas Marsh-Armstrong
- Department of Ophthalmology & Vision Science, University of California Davis Eye Center, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
| | - Robert J Zawadzki
- UC Davis EyePod Small Animals Ocular Imaging Laboratory, University of California Davis, Davis, CA 95616, USA
- Center for Human Ocular Imaging Research (CHOIR), Dept. of Ophthalmology & Vision Science, University of California Davis, 4860 Y Street, Suite 2400, Sacramento, CA 95817, USA
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6
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Soucy JR, Aguzzi EA, Cho J, Gilhooley MJ, Keuthan C, Luo Z, Monavarfeshani A, Saleem MA, Wang XW, Wohlschlegel J, Baranov P, Di Polo A, Fortune B, Gokoffski KK, Goldberg JL, Guido W, Kolodkin AL, Mason CA, Ou Y, Reh TA, Ross AG, Samuels BC, Welsbie D, Zack DJ, Johnson TV. Retinal ganglion cell repopulation for vision restoration in optic neuropathy: a roadmap from the RReSTORe Consortium. Mol Neurodegener 2023; 18:64. [PMID: 37735444 PMCID: PMC10514988 DOI: 10.1186/s13024-023-00655-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/07/2023] [Indexed: 09/23/2023] Open
Abstract
Retinal ganglion cell (RGC) death in glaucoma and other optic neuropathies results in irreversible vision loss due to the mammalian central nervous system's limited regenerative capacity. RGC repopulation is a promising therapeutic approach to reverse vision loss from optic neuropathies if the newly introduced neurons can reestablish functional retinal and thalamic circuits. In theory, RGCs might be repopulated through the transplantation of stem cell-derived neurons or via the induction of endogenous transdifferentiation. The RGC Repopulation, Stem Cell Transplantation, and Optic Nerve Regeneration (RReSTORe) Consortium was established to address the challenges associated with the therapeutic repair of the visual pathway in optic neuropathy. In 2022, the RReSTORe Consortium initiated ongoing international collaborative discussions to advance the RGC repopulation field and has identified five critical areas of focus: (1) RGC development and differentiation, (2) Transplantation methods and models, (3) RGC survival, maturation, and host interactions, (4) Inner retinal wiring, and (5) Eye-to-brain connectivity. Here, we discuss the most pertinent questions and challenges that exist on the path to clinical translation and suggest experimental directions to propel this work going forward. Using these five subtopic discussion groups (SDGs) as a framework, we suggest multidisciplinary approaches to restore the diseased visual pathway by leveraging groundbreaking insights from developmental neuroscience, stem cell biology, molecular biology, optical imaging, animal models of optic neuropathy, immunology & immunotolerance, neuropathology & neuroprotection, materials science & biomedical engineering, and regenerative neuroscience. While significant hurdles remain, the RReSTORe Consortium's efforts provide a comprehensive roadmap for advancing the RGC repopulation field and hold potential for transformative progress in restoring vision in patients suffering from optic neuropathies.
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Affiliation(s)
- Jonathan R Soucy
- Department of Ophthalmology, Schepens Eye Research Institute of Mass. Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Erika A Aguzzi
- The Institute of Ophthalmology, University College London, London, England, UK
| | - Julie Cho
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Michael James Gilhooley
- The Institute of Ophthalmology, University College London, London, England, UK
- Moorfields Eye Hospital, London, England, UK
| | - Casey Keuthan
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ziming Luo
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - Aboozar Monavarfeshani
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
- Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Meher A Saleem
- Bascom Palmer Eye Institute, University of Miami Health System, Miami, FL, USA
| | - Xue-Wei Wang
- Department of Orthopaedic Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Petr Baranov
- Department of Ophthalmology, Schepens Eye Research Institute of Mass. Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Adriana Di Polo
- Department of Neuroscience, University of Montreal, Montreal, QC, Canada
- University of Montreal Hospital Research Centre, Montreal, QC, Canada
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Health, Portland, OR, USA
| | - Kimberly K Gokoffski
- Department of Ophthalmology, Roski Eye Institute, University of Southern California, Los Angeles, CA, USA
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, USA
| | - William Guido
- Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY, USA
| | - Alex L Kolodkin
- The Solomon H Snyder, Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Carol A Mason
- Departments of Pathology and Cell Biology, Neuroscience, and Ophthalmology, College of Physicians and Surgeons, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - Yvonne Ou
- Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, Seattle, WA, USA
| | - Ahmara G Ross
- Departments of Ophthalmology and Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Brian C Samuels
- Department of Ophthalmology and Visual Sciences, Callahan Eye Hospital, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Derek Welsbie
- Shiley Eye Institute and Viterbi Family Department of Ophthalmology, University of California, San Diego, CA, USA
| | - Donald J Zack
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, 21287 MD, USA
- Departments of Neuroscience, Molecular Biology & Genetics, and Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Thomas V Johnson
- Departments of Neuroscience, Molecular Biology & Genetics, and Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Cellular & Molecular Medicine Program, Johns Hopkins University School of Medicine, Baltimore, 21287 MD, USA.
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Sabeti F, Rai BB, van Kleef JP, Rohan EMF, Carle CF, Barry RC, Essex RW, Nolan CJ, Maddess T. Objective perimetry identifies regional functional progression and recovery in mild Diabetic Macular Oedema. PLoS One 2023; 18:e0287319. [PMID: 37319294 PMCID: PMC10270604 DOI: 10.1371/journal.pone.0287319] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 06/02/2023] [Indexed: 06/17/2023] Open
Abstract
PURPOSE Retinal function beyond foveal vision is not routinely examined in the clinical screening and management of diabetic retinopathy although growing evidence suggests it may precede structural changes. In this study we compare optical coherence tomography (OCT) based macular structure with function measured objectively with the ObjectiveFIELD Analyzer (OFA), and with Matrix perimetry. We did that longitudinally in Type 2 diabetes (T2D) patients with mild Diabetic Macular Oedema (DMO) with good vision and a similar number of T2D patients without DMO, to evaluate changes in retinal function more peripherally over the natural course of retinopathy. METHODS Both eyes of 16 T2D patients (65.0 ± 10.1, 10 females), 10 with baseline DMO, were followed for up longitudinally for 27 months providing 94 data sets. Vasculopathy was assessed by fundus photography. Retinopathy was graded using to Early Treatment of Diabetic Retinopathy Study (ETDRS) guidelines. Posterior-pole OCT quantified a 64-region/eye thickness grid. Retinal function was measured with 10-2 Matrix perimetry, and the FDA-cleared OFA. Two multifocal pupillographic objective perimetry (mfPOP) variants presented 44 stimuli/eye within either the central 30° or 60° of the visual field, providing sensitivities and delays for each test-region. OCT, Matrix and 30° OFA data were mapped to a common 44 region/eye grid allowing change over time to be compared at the same retinal regions. RESULTS In eyes that presented with DMO at baseline, mean retinal thickness reduced from 237 ± 25 μm to 234.2 ± 26.7 μm, while the initially non-DMO eyes significantly increased their mean thickness from 250.7 ± 24.4 μm to 255.7 ± 20.6 μm (both p<0.05). Eyes that reduced in retinal thickness over time recovered to more normal OFA sensitivities and delays (all p<0.021). Matrix perimetry quantified fewer regions that changed significantly over the 27 months, mostly presenting in the central 8 degrees. CONCLUSIONS Changes in retinal function measured by OFA possibly offer greater power to monitor DMO over time than Matrix perimetry data.
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Affiliation(s)
- Faran Sabeti
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
- Faculty of Health, School of Optometry, University of Canberra, Bruce, Canberra, Australia
| | - Bhim B. Rai
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Josh P. van Kleef
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Emilie M. F. Rohan
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Corinne F. Carle
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Richard C. Barry
- The Canberra Hospital, ACT Health, Garran, Canberra, ACT, Australia
- Blink Eye Clinic, Canberra, ACT, Australia
| | - Rohan W. Essex
- The Canberra Hospital, ACT Health, Garran, Canberra, ACT, Australia
- ANU Medical School, Australian National University, Canberra, ACT, Australia
| | - Christopher J. Nolan
- The Canberra Hospital, ACT Health, Garran, Canberra, ACT, Australia
- ANU Medical School, Australian National University, Canberra, ACT, Australia
| | - Ted Maddess
- The John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
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8
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Murphy OC, Sotirchos ES, Kalaitzidis G, Vasileiou E, Ehrhardt H, Lambe J, Kwakyi O, Nguyen J, Lee AZ, Button J, Dewey BE, Newsome SD, Mowry EM, Fitzgerald KC, Prince JL, Calabresi PA, Saidha S. Trans-Synaptic Degeneration Following Acute Optic Neuritis in Multiple Sclerosis. Ann Neurol 2023; 93:76-87. [PMID: 36218157 PMCID: PMC9933774 DOI: 10.1002/ana.26529] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 10/07/2022] [Accepted: 10/07/2022] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To explore longitudinal changes in brain volumetric measures and retinal layer thicknesses following acute optic neuritis (AON) in people with multiple sclerosis (PwMS), to investigate the process of trans-synaptic degeneration, and determine its clinical relevance. METHODS PwMS were recruited within 40 days of AON onset (n = 49), and underwent baseline retinal optical coherence tomography and brain magnetic resonance imaging followed by longitudinal tracking for up to 5 years. A comparator cohort of PwMS without a recent episode of AON were similarly tracked (n = 73). Mixed-effects linear regression models were used. RESULTS Accelerated atrophy of the occipital gray matter (GM), calcarine GM, and thalamus was seen in the AON cohort, as compared with the non-AON cohort (-0.76% vs -0.22% per year [p = 0.01] for occipital GM, -1.83% vs -0.32% per year [p = 0.008] for calcarine GM, -1.17% vs -0.67% per year [p = 0.02] for thalamus), whereas rates of whole-brain, cortical GM, non-occipital cortical GM atrophy, and T2 lesion accumulation did not differ significantly between the cohorts. In the AON cohort, greater AON-induced reduction in ganglion cell+inner plexiform layer thickness over the first year was associated with faster rates of whole-brain (r = 0.32, p = 0.04), white matter (r = 0.32, p = 0.04), and thalamic (r = 0.36, p = 0.02) atrophy over the study period. Significant relationships were identified between faster atrophy of the subcortical GM and thalamus, with worse visual function outcomes after AON. INTERPRETATION These results provide in-vivo evidence for anterograde trans-synaptic degeneration following AON in PwMS, and suggest that trans-synaptic degeneration may be related to clinically-relevant visual outcomes. ANN NEUROL 2023;93:76-87.
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Affiliation(s)
- Olwen C. Murphy
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Elias S. Sotirchos
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Grigorios Kalaitzidis
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Elena Vasileiou
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Henrik Ehrhardt
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Jeffrey Lambe
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Ohemaa Kwakyi
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - James Nguyen
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Alexandra Zambriczki Lee
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Julia Button
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Blake E. Dewey
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, USA
| | - Scott D. Newsome
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Ellen M. Mowry
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Kathryn C. Fitzgerald
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Jerry L. Prince
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, USA
| | - Peter A. Calabresi
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
| | - Shiv Saidha
- Division of Neuroimmunology and Neurological Infections, Department of Neurology, Johns Hopkins University, Baltimore, USA
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9
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Van Hook MJ. Influences of Glaucoma on the Structure and Function of Synapses in the Visual System. Antioxid Redox Signal 2022; 37:842-861. [PMID: 35044228 PMCID: PMC9587776 DOI: 10.1089/ars.2021.0253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/31/2021] [Indexed: 11/12/2022]
Abstract
Significance: Glaucoma is an age-related neurodegenerative disorder of the visual system associated with sensitivity to intraocular pressure (IOP). It is the leading irreversible cause of vision loss worldwide, and vision loss results from damage and dysfunction of the retinal output neurons known as retinal ganglion cells (RGCs). Recent Advances: Elevated IOP and optic nerve injury triggers pruning of RGC dendrites, altered morphology of excitatory inputs from presynaptic bipolar cells, and disrupted RGC synaptic function. Less is known about RGC outputs, although evidence to date indicates that glaucoma is associated with altered mitochondrial and synaptic structure and function in RGC-projection targets in the brain. These early functional changes likely contribute to vision loss and might be a window into early diagnosis and treatment. Critical Issues: Glaucoma affects different RGC populations to varying extents and along distinct time courses. The influence of glaucoma on RGC synaptic function as well as the mechanisms underlying these effects remain to be determined. Since RGCs are an especially energetically demanding population of neurons, altered intracellular axon transport of mitochondria and mitochondrial function might contribute to RGC synaptic dysfunction in the retina and brain as well as RGC vulnerability in glaucoma. Future Directions: The mechanisms underlying differential RGC vulnerability remain to be determined. Moreover, the timing and mechanisms of RGCs synaptic dysfunction and degeneration will provide valuable insight into the disease process in glaucoma. Future work will be able to capitalize on these findings to better design diagnostic and therapeutic approaches to detect disease and prevent vision loss. Antioxid. Redox Signal. 37, 842-861.
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Affiliation(s)
- Matthew J. Van Hook
- Department of Ophthalmology & Visual Science and Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
- Department of Cellular & Integrative Physiology, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, Nebraska, USA
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10
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Chronic Chemogenetic Activation of the Superior Colliculus in Glaucomatous Mice: Local and Retrograde Molecular Signature. Cells 2022; 11:cells11111784. [PMID: 35681479 PMCID: PMC9179903 DOI: 10.3390/cells11111784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/20/2022] [Accepted: 05/22/2022] [Indexed: 12/13/2022] Open
Abstract
One important facet of glaucoma pathophysiology is axonal damage, which ultimately disrupts the connection between the retina and its postsynaptic brain targets. The concurrent loss of retrograde support interferes with the functionality and survival of the retinal ganglion cells (RGCs). Previous research has shown that stimulation of neuronal activity in a primary retinal target area—i.e., the superior colliculus—promotes RGC survival in an acute mouse model of glaucoma. To build further on this observation, we applied repeated chemogenetics in the superior colliculus of a more chronic murine glaucoma model—i.e., the microbead occlusion model—and performed bulk RNA sequencing on collicular lysates and isolated RGCs. Our study revealed that chronic target stimulation upon glaucomatous injury phenocopies the a priori expected molecular response: growth factors were pinpointed as essential transcriptional regulators both in the locally stimulated tissue and in distant, unstimulated RGCs. Strikingly, and although the RGC transcriptome revealed a partial reversal of the glaucomatous signature and an enrichment of pro-survival signaling pathways, functional rescue of injured RGCs was not achieved. By postulating various explanations for the lack of RGC neuroprotection, we aim to warrant researchers and drug developers for the complexity of chronic neuromodulation and growth factor signaling.
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11
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Hetzer SM, Shalosky EM, Torrens JN, Evanson NK. Chronic Histological Outcomes of Indirect Traumatic Optic Neuropathy in Adolescent Mice: Persistent Degeneration and Temporally Regulated Glial Responses. Cells 2021; 10:3343. [PMID: 34943851 PMCID: PMC8699438 DOI: 10.3390/cells10123343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 11/17/2022] Open
Abstract
Injury to the optic nerve, termed, traumatic optic neuropathy (TON) is a known comorbidity of traumatic brain injury (TBI) and is now known to cause chronic and progressive retinal thinning up to 35 years after injury. Although animal models of TBI have described the presence of optic nerve degeneration and research exploring acute mechanisms is underway, few studies in humans or animals have examined chronic TON pathophysiology outside the retina. We used a closed-head weight-drop model of TBI/TON in 6-week-old male C57BL/6 mice. Mice were euthanized 7-, 14-, 30-, 90-, and 150-days post-injury (DPI) to assess histological changes in the visual system of the brain spanning a total of 12 regions. We show chronic elevation of FluoroJade-C, indicative of neurodegeneration, throughout the time course. Intriguingly, FJ-C staining revealed a bimodal distribution of mice indicating the possibility of subpopulations that may be more or less susceptible to injury outcomes. Additionally, we show that microglia and astrocytes react to optic nerve damage in both temporally and regionally different ways. Despite these differences, astrogliosis and microglial changes were alleviated between 14-30 DPI in all regions examined, perhaps indicating a potentially critical period for intervention/recovery that may determine chronic outcomes.
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Affiliation(s)
- Shelby M. Hetzer
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA;
| | - Emily M. Shalosky
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221, USA;
| | - Jordyn N. Torrens
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
| | - Nathan K. Evanson
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA;
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45229, USA
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12
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Di Pierdomenico J, Henderson DCM, Giammaria S, Smith VL, Jamet AJ, Smith CA, Hooper ML, Chauhan BC. Age and intraocular pressure in murine experimental glaucoma. Prog Retin Eye Res 2021; 88:101021. [PMID: 34801667 DOI: 10.1016/j.preteyeres.2021.101021] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/25/2021] [Accepted: 11/08/2021] [Indexed: 12/23/2022]
Abstract
Age and intraocular pressure (IOP) are the two most important risk factors for the development and progression of open-angle glaucoma. While IOP is commonly considered in models of experimental glaucoma (EG), most studies use juvenile or adult animals and seldom older animals which are representative of the human disease. This paper provides a concise review of how retinal ganglion cell (RGC) loss, the hallmark of glaucoma, can be evaluated in EG with a special emphasis on serial in vivo imaging, a parallel approach used in clinical practice. It appraises the suitability of EG models for the purpose of in vivo imaging and argues for the use of models that provide a sustained elevation of IOP, without compromise of the ocular media. In a study with parallel cohorts of adult (3-month-old, equivalent to 20 human years) and old (2-year-old, equivalent to 70 human years) mice, we compare the effects of elevated IOP on serial ganglion cell complex thickness and individual RGC dendritic morphology changes obtained in vivo. We also evaluate how age modulates the impact of elevated IOP on RGC somal and axonal density in histological analysis as well the density of melanopsin RGCs. We discuss the challenges of using old animals and emphasize the potential of single RGC imaging for understanding the pathobiology of RGC loss and evaluating new therapeutic avenues.
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Affiliation(s)
- Johnny Di Pierdomenico
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Delaney C M Henderson
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Sara Giammaria
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Victoria L Smith
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Aliénor J Jamet
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Corey A Smith
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michele L Hooper
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Balwantray C Chauhan
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada.
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13
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Midena E, Torresin T, Longhin E, Midena G, Pilotto E, Frizziero L. Early Microvascular and Oscillatory Potentials Changes in Human Diabetic Retina: Amacrine Cells and the Intraretinal Neurovascular Crosstalk. J Clin Med 2021; 10:jcm10184035. [PMID: 34575150 PMCID: PMC8466765 DOI: 10.3390/jcm10184035] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 08/31/2021] [Accepted: 09/03/2021] [Indexed: 12/22/2022] Open
Abstract
To analyze the early microvascular retinal changes and oscillatory potentials alterations secondary to diabetic retinal damage, 44 eyes of 22 diabetic patients without and with mild diabetic retinopathy (DR) and 18 eyes of 9 healthy controls were examined. All subjects underwent spectral domain optical coherence tomography (SD-OCT), OCT angiography (OCTA), and electroretinography of oscillatory potentials (OPs). At OCTA, vessel area density (VAD), vessel length fraction (VLF), and fractal dimension (FD) were significantly reduced in the superficial vascular plexus (SVP), VLF and FD in the intermediate capillary plexus (ICP), and FD in the deep capillary plexus (DCP) in the diabetic group compared to the control group. The amplitude (A) of OP2, OP3, OP4 and the sum of OPs were significantly reduced in the diabetic group versus the controls, and the last two parameters were reduced also in patients without DR versus the controls. Moreover, in the diabetic group, a significant direct correlation was found between the A of OP1, OP2, OP3 and sOP and the VLF and FD in the SVP, while a statistically significant inverse correlation was found between the A of OP3 and OP4 and the VDI in the ICP and DCP. The reduced oscillatory potentials suggest a precocious involvement of amacrine cells in diabetic eyes, independently of DR presence, and their correlation with vascular parameters underlines the relevance of the crosstalk between these cells and vascular components in the pathophysiology of this chronic disease.
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Affiliation(s)
- Edoardo Midena
- Department of Neuroscience—Ophthalmology, University of Padova, 35128 Padova, Italy; (T.T.); (E.L.); (E.P.); (L.F.)
- IRCCS—Fondazione Bietti, 00198 Rome, Italy;
- Correspondence: ; Tel.: +39-049-821-2110
| | - Tommaso Torresin
- Department of Neuroscience—Ophthalmology, University of Padova, 35128 Padova, Italy; (T.T.); (E.L.); (E.P.); (L.F.)
| | - Evelyn Longhin
- Department of Neuroscience—Ophthalmology, University of Padova, 35128 Padova, Italy; (T.T.); (E.L.); (E.P.); (L.F.)
| | | | - Elisabetta Pilotto
- Department of Neuroscience—Ophthalmology, University of Padova, 35128 Padova, Italy; (T.T.); (E.L.); (E.P.); (L.F.)
| | - Luisa Frizziero
- Department of Neuroscience—Ophthalmology, University of Padova, 35128 Padova, Italy; (T.T.); (E.L.); (E.P.); (L.F.)
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14
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Henderson DCM, Vianna JR, Gobran J, Pierdomenico JD, Hooper ML, Farrell SRM, Chauhan BC. Longitudinal In Vivo Changes in Retinal Ganglion Cell Dendritic Morphology After Acute and Chronic Optic Nerve Injury. Invest Ophthalmol Vis Sci 2021; 62:5. [PMID: 34232261 PMCID: PMC8267182 DOI: 10.1167/iovs.62.9.5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To characterize in vivo dendritic changes in retinal ganglion cells (RGCs) after acute (optic nerve transection, ONT) and chronic (experimental glaucoma, EG) optic nerve injury. Methods ONT and EG (microbead model) were carried out in Thy1-YFP mice in which the entire RGC dendritic arbor was imaged with confocal fluorescence scanning laser ophthalmoscopy over two weeks in the ONT group and over two and six months, respectively, in two (groups 1 and 2) EG groups. Sholl analysis was used to quantify dendritic structure with the parameters: area under the curve (AUC), radius of the dendritic field, peak number of intersections (PI), and distance to the PI (PD). Results Dendritic changes were observed after three days post-ONT with significant decreases in all parameters at two weeks. In group 1 EG mice, mean (SD) intraocular pressure (IOP) was 15.2 (1.1) and 9.8 (0.3) mmHg in the EG and untreated contralateral eyes, respectively, with a significant corresponding decrease in AUC, PI, and PD, but not radius. In group 2 mice, the respective IOP was 13.1 (1.0) and 8.8 (0.1) mmHg, peaking at two months before trending towards baseline. Over the first two months, AUC, PI, and PD decreased significantly, with no further subsequent changes. The rates of change of the parameters after ONT was 5 to 10 times faster than in EG. Conclusions Rapid dendritic changes occurred after ONT, while changes in EG were slower and associated with level of IOP increase. The earliest alterations were loss of inner neurites without change in dendritic field.
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Affiliation(s)
- Delaney C M Henderson
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jayme R Vianna
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - John Gobran
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Johnny Di Pierdomenico
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michele L Hooper
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Spring R M Farrell
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Balwantray C Chauhan
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
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15
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Lee JS, Lee K, Seong GJ, Kim CY, Lee SY, Bae HW. Clinical Predictors of the Region of First Structural Progression in Early Normal-tension Glaucoma. KOREAN JOURNAL OF OPHTHALMOLOGY 2021; 34:322-333. [PMID: 32783426 PMCID: PMC7419233 DOI: 10.3341/kjo.2020.0011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 04/14/2020] [Accepted: 04/23/2020] [Indexed: 11/23/2022] Open
Abstract
PURPOSE This study aimed to compare the clinical characteristics of patients who showed structural progression in the peripapillary retinal nerve fiber layer (RNFL) first against those who showed progression in the macular ganglion cell-inner plexiform layer (GCIPL) first and to investigate clinical parameters that help determine whether a patient exhibits RNFL or GCIPL damage first. METHODS A retrospective review of medical records of patients diagnosed with early-stage normal-tension glaucoma was performed. All eyes underwent intraocular pressure measurement with Goldmann applanation tonometer, standard automated perimetry, and Cirrus optical coherence tomography at 6-month intervals. Structural progression was determined using the Guided Progression Analysis software. Blood pressure was measured at each visit. RESULTS Forty-one eyes of 41 patients (mean age, 52.6 ± 16.7 years) were included in the study. In 21 eyes, structural progression was first detected in the RNFL at 54.2 ± 14.8 months, while structural progression was first observed at the macular GCIPL at 40.5 ± 11.0 months in 20 eyes. The mean intraocular pressure following treatment was 13.1 ± 1.8 mmHg for the RNFL progression first group and 13.4 ± 1.8 mmHg for the GCIPL progression first group (p = 0.514). The GCIPL progression first group was older (p = 0.008) and had thinner RNFL at baseline (p = 0.001). The logistic regression analyses indicated that both age and follow-up duration until first progression predicted the region of structural progression (odds ratio, 1.051; 95% confidence interval, 1.001-1.105; p = 0.046 for age; odds ratio, 0.912; 95% confidence interval, 0.840-0.991; p = 0.029 for time until progression). CONCLUSIONS Age of glaucoma patients and time until progression are associated with the region of the first structural progression in normal-tension glaucoma. Further studies exploring the association between glaucomatous progression and the location of damage are needed.
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Affiliation(s)
- Jihei Sara Lee
- Department of Ophthalmology, Institute of Vision Research, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Kwanghyun Lee
- Department of Ophthalmology, Institute of Vision Research, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.,Department of Ophthalmology, National Health Insurance Service Ilsan Hospital, Goyang, Korea
| | - Gong Je Seong
- Department of Ophthalmology, Institute of Vision Research, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Chan Yun Kim
- Department of Ophthalmology, Institute of Vision Research, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Sang Yeop Lee
- Department of Ophthalmology, Institute of Vision Research, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Hyoung Won Bae
- Department of Ophthalmology, Institute of Vision Research, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
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16
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Muench NA, Patel S, Maes ME, Donahue RJ, Ikeda A, Nickells RW. The Influence of Mitochondrial Dynamics and Function on Retinal Ganglion Cell Susceptibility in Optic Nerve Disease. Cells 2021; 10:cells10071593. [PMID: 34201955 PMCID: PMC8306483 DOI: 10.3390/cells10071593] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/15/2021] [Accepted: 06/17/2021] [Indexed: 12/30/2022] Open
Abstract
The important roles of mitochondrial function and dysfunction in the process of neurodegeneration are widely acknowledged. Retinal ganglion cells (RGCs) appear to be a highly vulnerable neuronal cell type in the central nervous system with respect to mitochondrial dysfunction but the actual reasons for this are still incompletely understood. These cells have a unique circumstance where unmyelinated axons must bend nearly 90° to exit the eye and then cross a translaminar pressure gradient before becoming myelinated in the optic nerve. This region, the optic nerve head, contains some of the highest density of mitochondria present in these cells. Glaucoma represents a perfect storm of events occurring at this location, with a combination of changes in the translaminar pressure gradient and reassignment of the metabolic support functions of supporting glia, which appears to apply increased metabolic stress to the RGC axons leading to a failure of axonal transport mechanisms. However, RGCs themselves are also extremely sensitive to genetic mutations, particularly in genes affecting mitochondrial dynamics and mitochondrial clearance. These mutations, which systemically affect the mitochondria in every cell, often lead to an optic neuropathy as the sole pathologic defect in affected patients. This review summarizes knowledge of mitochondrial structure and function, the known energy demands of neurons in general, and places these in the context of normal and pathological characteristics of mitochondria attributed to RGCs.
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Affiliation(s)
- Nicole A. Muench
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (N.A.M.); (S.P.); (R.J.D.)
| | - Sonia Patel
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (N.A.M.); (S.P.); (R.J.D.)
| | - Margaret E. Maes
- Institute of Science and Technology Austria, 3400 Klosterneuburg, Austria;
| | - Ryan J. Donahue
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (N.A.M.); (S.P.); (R.J.D.)
- Boston Children’s Hospital, Harvard Medical School, Harvard University, Boston, MA 02115, USA
| | - Akihiro Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA;
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Robert W. Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA; (N.A.M.); (S.P.); (R.J.D.)
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
- Correspondence:
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17
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Li L, Deng F, Qiu H, Li Y, Gong Z, Wang L, Wang J, Wu W, Nan K. An adherent drug depot for retinal ganglion cell protection and regeneration in rat traumatic optic neuropathy models. RSC Adv 2021; 11:22761-22772. [PMID: 35480428 PMCID: PMC9034353 DOI: 10.1039/d0ra10362d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 06/21/2021] [Indexed: 11/21/2022] Open
Abstract
Traumatic optic neuropathy (TON) describes an injury to the optic nerve following either blunt or penetrating trauma, and remains an important cause of vision loss. No generalized treatment of TON has been established so far to restore the injured optic nerve. We developed an adherent drug-encapsulated bi-layered depot (DBP) as a dual drug vehicle for local treatment to protect the residual retinal ganglion cells (RGCs) and regenerate axons following optic nerve damage. The inner layer of the depot was prepared by co-electrospinning poly(d,l-lactide-co-glycolide acid) (PLGA: 75 : 25) and collagen (COL) with the hydrophobic corticosteroid triamcinolone acetonide (TA) loaded. The outer layer was made of PLGA and the hydrophilic neuroprotective agent Fasudil (FA). The DBP showed suitable morphology, hydrophilicity and mechanical properties, and slowly released TA and FA in vitro by undergoing time-dependent degradation and swelling. All depots showed good biocompatibility with L929 mouse fibroblasts, and DBP was helpful in maintaining the morphology of RGCs in vitro. In addition, direct implantation of DBP at the injured optic nerve in a rat model mitigated inflammation and the death of RGCs, and increased the expression of nerve growth-related protein GAP-43. Therefore, DBP maybe a promising local therapy against TON in future.
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Affiliation(s)
- Lingli Li
- School of Ophthalmology & Optometry, Affiliated Eye Hospital, Wenzhou Medical University Zhejiang Province P. R. China .,State Key Laboratory of Ophthalmology, Optometry and Visual Science Zhejiang Province P. R. China
| | - Fen Deng
- School of Ophthalmology & Optometry, Affiliated Eye Hospital, Wenzhou Medical University Zhejiang Province P. R. China .,The 2nd Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University Zhejiang Province P. R. China
| | - Haijun Qiu
- School of Ophthalmology & Optometry, Affiliated Eye Hospital, Wenzhou Medical University Zhejiang Province P. R. China .,State Key Laboratory of Ophthalmology, Optometry and Visual Science Zhejiang Province P. R. China
| | - Yao Li
- School of Ophthalmology & Optometry, Affiliated Eye Hospital, Wenzhou Medical University Zhejiang Province P. R. China .,State Key Laboratory of Ophthalmology, Optometry and Visual Science Zhejiang Province P. R. China
| | - Zan Gong
- School of Ophthalmology & Optometry, Affiliated Eye Hospital, Wenzhou Medical University Zhejiang Province P. R. China .,State Key Laboratory of Ophthalmology, Optometry and Visual Science Zhejiang Province P. R. China
| | - Lei Wang
- University of Chinese Academy of Sciences Wenzhou Institute Zhejiang Province P. R. China.,Engineering Research Center of Clinical Functional Materials and Diagnosis & Treatment Devices of Zhejiang Province, Wenzhou Institute of Biomaterials and Engineering Wenzhou Zhejiang 325027 China
| | - Jingjie Wang
- School of Ophthalmology & Optometry, Affiliated Eye Hospital, Wenzhou Medical University Zhejiang Province P. R. China .,State Key Laboratory of Ophthalmology, Optometry and Visual Science Zhejiang Province P. R. China
| | - Wencan Wu
- School of Ophthalmology & Optometry, Affiliated Eye Hospital, Wenzhou Medical University Zhejiang Province P. R. China .,State Key Laboratory of Ophthalmology, Optometry and Visual Science Zhejiang Province P. R. China
| | - Kaihui Nan
- School of Ophthalmology & Optometry, Affiliated Eye Hospital, Wenzhou Medical University Zhejiang Province P. R. China .,State Key Laboratory of Ophthalmology, Optometry and Visual Science Zhejiang Province P. R. China
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A Fair Assessment of Evaluation Tools for the Murine Microbead Occlusion Model of Glaucoma. Int J Mol Sci 2021; 22:ijms22115633. [PMID: 34073191 PMCID: PMC8199180 DOI: 10.3390/ijms22115633] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/14/2021] [Accepted: 05/19/2021] [Indexed: 02/06/2023] Open
Abstract
Despite being one of the most studied eye diseases, clinical translation of glaucoma research is hampered, at least in part, by the lack of validated preclinical models and readouts. The most popular experimental glaucoma model is the murine microbead occlusion model, yet the observed mild phenotype, mixed success rate, and weak reproducibility urge for an expansion of available readout tools. For this purpose, we evaluated various measures that reflect early onset glaucomatous changes in the murine microbead occlusion model. Anterior chamber depth measurements and scotopic threshold response recordings were identified as an outstanding set of tools to assess the model’s success rate and to chart glaucomatous damage (or neuroprotection in future studies), respectively. Both are easy-to-measure, in vivo tools with a fast acquisition time and high translatability to the clinic and can be used, whenever judged beneficial, in combination with the more conventional measures in present-day glaucoma research (i.e., intraocular pressure measurements and post-mortem histological analyses). Furthermore, we highlighted the use of dendritic arbor analysis as an alternative histological readout for retinal ganglion cell density counts.
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19
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Ye C, Wang X, Yu MCY, Shang X, Zhou K, Tao Y, Lu F, Liang Y. Progression of Macular Vessel Density in Primary Open-Angle Glaucoma: A Longitudinal Study. Am J Ophthalmol 2021; 223:259-266. [PMID: 33351744 DOI: 10.1016/j.ajo.2020.10.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/13/2020] [Accepted: 10/15/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To evaluate the rate of progression of macular vessel density (mVD) in primary open-angle glaucoma (POAG) and explore the relationship between the progression of mVD and macular ganglion cell-inner plexiform layer (mGCIPL) thickness and parapapillary retinal nerve fiber layer (pRNFL) thickness. DESIGN Prospective cohort study. METHODS In this study, 102 eyes with POAG were followed for 36.6 ± 6.4 months. The rates of progression were estimated by linear models. The agreement of progression detection among the 3 parameters was evaluated with Kappa statistics. The influence of baseline measurements on the rates of progression of mGCIPL thickness, pRNFL thickness, and mVD was investigated by linear mixed modeling. Kaplan-Meier survival analysis was adopted to calculate the survival probabilities. RESULTS The respective rate of progression by linear regression was -0.102 ± 0.054 μm/month, -0.160 ± 0.086 μm/month, and -0.199 ± 0.073 %/month for mGCIPL thickness, pRNFL thickness, and mVD. The agreement in detection of progression among them was poor with the Conger's Kappa coefficient of 0.098 (95% confidence interval: -0.025~0.220, P = .116). The significant factors influencing the rate of progression of mVD were baseline mGCIPL thickness, baseline pRNFL thickness, and baseline mVD (P ≤ .001), while baseline mVD was not a significant factor influencing the rates of progression of mGCIPL thickness and pRNFL thickness (P ≥ .659). Also, pRNFL thickness had a better survival probability compared with the other 2 parameters (P = .025). CONCLUSIONS The mGCIPL thickness, pRNFL thickness, and mVD decreased over time in POAG eyes. The rate of reduction of mVD was significantly influenced by the baseline measurements of mGCIPL thickness, pRNFL thickness, and mVD.
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20
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Orduna-Hospital E, Otero-Rodríguez J, Perdices L, Sánchez-Cano A, Boned-Murillo A, Acha J, Pinilla I. Microperimetry and Optical Coherence Tomography Changes in Type-1 Diabetes Mellitus without Retinopathy. Diagnostics (Basel) 2021; 11:diagnostics11010136. [PMID: 33467213 PMCID: PMC7830999 DOI: 10.3390/diagnostics11010136] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/12/2021] [Accepted: 01/13/2021] [Indexed: 11/16/2022] Open
Abstract
Background: We aimed to measure and correlate inner retinal layer (IRL) thickness and macular sensitivity by optical coherence tomography (OCT) and by microperimetry, respectively, in type 1 diabetes mellitus patients (DM1) without diabetic retinopathy (DR). Methods: Fifty-one DM1 patients and 81 age-matched healthy subjects underwent measurement of the axial length (AL), retinal thickness in the macular ETDRS areas by swept source (SS)-OCT and macular sensitivity by microperimeter. Results: The total retinal and IRL thicknesses were thicker in the DM1 group (p < 0.05) in practically all ETDRS areas, and they had a generalized decrease in sensitivity (p < 0.05) in 9 areas between both groups. There was a significant negative correlation between retinal sensitivity and age in all areas and in visual acuity (VA) in 5 out of the 9 areas for DM1 patients. Only a mild negative correlation was observed between retinal sensitivity in the 5° nasal inner (5NI) area and in IRL thickness in the temporal inner (TI) area (−0.309 with p = 0.029) in the DM1 group. Conclusion: Aging and disease evolution in DM1 patients without DR signs generate a decrease in retinal sensitivity. There was a direct relationship between retinal sensitivity and macular thickness in the DM1 group.
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Affiliation(s)
- Elvira Orduna-Hospital
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain; (E.O.-H.); (L.P.); (A.S.-C.); (A.B.-M.); (J.A.)
- Department of Applied Physics, University of Zaragoza, 50009 Zaragoza, Spain;
| | | | - Lorena Perdices
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain; (E.O.-H.); (L.P.); (A.S.-C.); (A.B.-M.); (J.A.)
| | - Ana Sánchez-Cano
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain; (E.O.-H.); (L.P.); (A.S.-C.); (A.B.-M.); (J.A.)
- Department of Applied Physics, University of Zaragoza, 50009 Zaragoza, Spain;
| | - Ana Boned-Murillo
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain; (E.O.-H.); (L.P.); (A.S.-C.); (A.B.-M.); (J.A.)
- Department of Ophthalmology, Lozano Blesa University Hospital, 50009 Zaragoza, Spain
| | - Javier Acha
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain; (E.O.-H.); (L.P.); (A.S.-C.); (A.B.-M.); (J.A.)
- Department of Endocrinology, Miguel Servet University Hospital, 50009 Zaragoza, Spain
| | - Isabel Pinilla
- Aragon Institute for Health Research (IIS Aragon), 50009 Zaragoza, Spain; (E.O.-H.); (L.P.); (A.S.-C.); (A.B.-M.); (J.A.)
- Department of Ophthalmology, Lozano Blesa University Hospital, 50009 Zaragoza, Spain
- Correspondence: ; Tel.: +34-696-808-295
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21
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Groleau M, Nazari-Ahangarkolaee M, Vanni MP, Higgins JL, Vézina Bédard AS, Sabel BA, Mohajerani MH, Vaucher E. Mesoscopic cortical network reorganization during recovery of optic nerve injury in GCaMP6s mice. Sci Rep 2020; 10:21472. [PMID: 33293617 PMCID: PMC7723052 DOI: 10.1038/s41598-020-78491-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/28/2020] [Indexed: 11/18/2022] Open
Abstract
As the residual vision following a traumatic optic nerve injury can spontaneously recover over time, we explored the spontaneous plasticity of cortical networks during the early post-optic nerve crush (ONC) phase. Using in vivo wide-field calcium imaging on awake Thy1-GCaMP6s mice, we characterized resting state and evoked cortical activity before, during, and 31 days after ONC. The recovery of monocular visual acuity and depth perception was evaluated in parallel. Cortical responses to an LED flash decreased in the contralateral hemisphere in the primary visual cortex and in the secondary visual areas following the ONC, but was partially rescued between 3 and 5 days post-ONC, remaining stable thereafter. The connectivity between visual and non-visual regions was disorganized after the crush, as shown by a decorrelation, but correlated activity was restored 31 days after the injury. The number of surviving retinal ganglion cells dramatically dropped and remained low. At the behavioral level, the ONC resulted in visual acuity loss on the injured side and an increase in visual acuity with the non-injured eye. In conclusion, our results show a reorganization of connectivity between visual and associative cortical areas after an ONC, which is indicative of spontaneous cortical plasticity.
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Affiliation(s)
- Marianne Groleau
- Laboratoire de Neurobiologie de la Cognition Visuelle, École d'Optométrie, Université de Montréal, Montréal, QC, H3T 1P1, Canada
| | - Mojtaba Nazari-Ahangarkolaee
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience (CCBN), University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada
| | - Matthieu P Vanni
- Laboratoire de Neurophotonique, École d'Optométrie, Université de Montréal, Montréal, QC, H3T 1P1, Canada
| | - Jacqueline L Higgins
- Laboratoire de Neurobiologie de la Cognition Visuelle, École d'Optométrie, Université de Montréal, Montréal, QC, H3T 1P1, Canada
| | - Anne-Sophie Vézina Bédard
- Laboratoire de Neurobiologie de la Cognition Visuelle, École d'Optométrie, Université de Montréal, Montréal, QC, H3T 1P1, Canada
| | - Bernhard A Sabel
- Institute of Medical Psychology, Medical Faculty, Otto-V.-Guericke University of Magdeburg, 39120, Magdeburg, Germany
| | - Majid H Mohajerani
- Department of Neuroscience, Canadian Centre for Behavioural Neuroscience (CCBN), University of Lethbridge, Lethbridge, AB, T1K 3M4, Canada.
| | - Elvire Vaucher
- Laboratoire de Neurobiologie de la Cognition Visuelle, École d'Optométrie, Université de Montréal, Montréal, QC, H3T 1P1, Canada.
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22
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Frizziero L, Midena G, Longhin E, Berton M, Torresin T, Parrozzani R, Pilotto E. Early Retinal Changes by OCT Angiography and Multifocal Electroretinography in Diabetes. J Clin Med 2020; 9:jcm9113514. [PMID: 33143008 PMCID: PMC7692230 DOI: 10.3390/jcm9113514] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 10/26/2020] [Accepted: 10/29/2020] [Indexed: 12/21/2022] Open
Abstract
Background: To evaluate the earliest retinal morphological and functional changes in diabetic eyes without or with early signs of diabetic retinopathy (DR). Methods: Twenty-two eyes with no DR (noDR group), 22 eyes with mild DR (DR group), and 18 healthy nondiabetic eyes (controls) were enrolled. All eyes were studied by means of spectral domain optical coherence tomography (OCT), OCT angiography (OCTA), and multifocal electroretinogram (mfERG). Results: A significantly higher number of OCT hyperreflective intraretinal foci (HRF) was found in both noDR and DR groups versus controls, but not between DR groups. The OCTA parameters of the superficial vascular plexus (SVP) were significantly reduced in the noDR group both versus controls and DR group (p < 0.05). The OCTA parameters of the intermediate capillary plexus (ICP) were significantly reduced in the DR group versus controls. An increased number of altered hexagons on mfERG was found in the noDR versus the DR group (p = 0.0192). Conclusions: Retinal vascular and functional parameters are differently involved in diabetic eyes; major vascular changes in the SVP and functional alterations of the mfERG are present in diabetic eyes with no clinical microvascular signs of DR, while ICP is mainly involved when early ophthalmoscopic signs of DR are present. The integrated use of mfERG and OCTA provides new significant insights into the pathogenesis of diabetic related retinal disease.
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Affiliation(s)
- Luisa Frizziero
- IRCCS—Fondazione Bietti, 00198 Rome, Italy
- Correspondence: ; Tel.: +39-049-821-2110
| | - Giulia Midena
- Institute of Ophthalmology, Policlinico Gemelli, IRCCS, 00168 Rome, Italy;
| | - Evelyn Longhin
- Department of Ophthalmology, University of Padova, 35128 Padova, Italy; (E.L.); (T.T.); (R.P.); (E.P.)
| | | | - Tommaso Torresin
- Department of Ophthalmology, University of Padova, 35128 Padova, Italy; (E.L.); (T.T.); (R.P.); (E.P.)
| | - Raffaele Parrozzani
- Department of Ophthalmology, University of Padova, 35128 Padova, Italy; (E.L.); (T.T.); (R.P.); (E.P.)
| | - Elisabetta Pilotto
- Department of Ophthalmology, University of Padova, 35128 Padova, Italy; (E.L.); (T.T.); (R.P.); (E.P.)
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23
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GCaMP3 expressing cells in the ganglion cell layer of Thy1-GCaMP3 transgenic mice before and after optic nerve injury. Exp Eye Res 2020; 202:108297. [PMID: 33045220 DOI: 10.1016/j.exer.2020.108297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 11/23/2022]
Abstract
The genetically encoded green fluorescent protein-based calcium sensor, GCaMP, has been used to detect calcium transients and report neuronal activity. We evaluated the specificity of GCaMP3 expression to retinal ganglion cells (RGCs) of the transgenic Thy1-GCaMP3 mouse line in healthy control animals and in those after optic nerve transection (ONT). Retinas from control mice (n = 4) were isolated and stained for RNA-binding protein with multiple splicing (RBPMS) and choline acetyltransferase (ChAT), specific markers for RGCs and cholinergic amacrine cells, respectively. GCaMP3 expression was enhanced with green fluorescent protein (GFP) immunoreactivity. In one subset of animals, ONT was performed 3, 7, or 14 days before sacrifice (n = 4, 4, 4, respectively). Cells positive for GCaMP3, RBPMS, ChAT, as well as the population of co-labeled cells, were quantified. In another subset of animals (n = 4), in vivo confocal scanning laser ophthalmoscope imaging was performed in the same mice at baseline and at 3, 7 and 14 days after ONT. The mean (SD) densities of GCaMP3, RBPMS, and ChAT expressing cells in control retinas were 2663 (110), 3401 (175), and 1041 (47) cells/mm2, respectively. Of the GCaMP3+ cells, 92 (1)% were co-labeled with RBPMS, while 72 (1)% of RBPMS-labeled cells expressed GCaMP3. ChAT expressing cells were not co-labeled with GCaMP3. The number of GCaMP3+ and RBPMS+ cells decreased dramatically after ONT; 78%, 39%, and 18% of GCaMP3+ and 80%, 40%, and 15% of RBPMS+ cells, relative to control retinas, survived at 3, 7, and 14 days after ONT. However, the number of ChAT+ cells did not change. There was a progressive decrease in GCaMP3 fluorescence after ONT in in vivo images. The majority of RGCs in the ganglion cell layer of Thy1-GCaMP3 mice express GCaMP3. There was an expected progressive and specific loss of GCaMP3 expression after ONT. Thy1-GCaMP3 transgenic mice have potential for longitudinal assessment of RGCs in injury models.
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24
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Yu J, Liang X, Ji Y, Ai C, Liu J, Zhu L, Nie Z, Jin X, Wang C, Zhang J, Zhao F, Mei S, Zhao X, Zhou X, Zhang M, Wang M, Huang T, Jiang P, Guan MX. PRICKLE3 linked to ATPase biogenesis manifested Leber's hereditary optic neuropathy. J Clin Invest 2020; 130:4935-4946. [PMID: 32516135 PMCID: PMC7456240 DOI: 10.1172/jci134965] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 06/04/2020] [Indexed: 12/16/2022] Open
Abstract
Leber's hereditary optic neuropathy (LHON) is a maternally inherited eye disease. X-linked nuclear modifiers were proposed to modify the phenotypic manifestation of LHON-associated mitochondrial DNA (mtDNA) mutations. By whole-exome sequencing, we identified the X-linked LHON modifier (c.157C>T, p.Arg53Trp) in PRICKLE3 encoding a mitochondrial protein linked to biogenesis of ATPase in 3 Chinese families. All affected individuals carried both ND4 11778G>A and p.Arg53Trp mutations, while subjects bearing only a single mutation exhibited normal vision. The cells carrying the p.Arg53Trp mutation exhibited defective assembly, stability, and function of ATP synthase, verified by PRICKLE3-knockdown cells. Coimmunoprecipitation indicated the direct interaction of PRICKLE3 with ATP synthase via ATP8. Strikingly, cells bearing both p.Arg53Trp and m.11778G>A mutations displayed greater mitochondrial dysfunction than those carrying only a single mutation. This finding indicated that the p.Arg53Trp mutation acted in synergy with the m.11778G>A mutation and deteriorated mitochondrial dysfunctions necessary for the expression of LHON. Furthermore, we demonstrated that Prickle3-deficient mice exhibited pronounced ATPase deficiencies. Prickle3-knockout mice recapitulated LHON phenotypes with retinal deficiencies, including degeneration of retinal ganglion cells and abnormal vasculature. Our findings provided new insights into the pathophysiology of LHON that were manifested by interaction between mtDNA mutations and X-linked nuclear modifiers.
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Affiliation(s)
- Jialing Yu
- Division of Medical Genetics and Genomics, Children’s Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, China
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Reproductive Genetics, Ministry of Education, Hangzhou, China
| | - Xiaoyang Liang
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Yanchun Ji
- Division of Medical Genetics and Genomics, Children’s Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, China
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Cheng Ai
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Junxia Liu
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Ling Zhu
- Division of Medical Genetics and Genomics, Children’s Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, China
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhipeng Nie
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaofen Jin
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Reproductive Genetics, Ministry of Education, Hangzhou, China
| | - Chenghui Wang
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Juanjuan Zhang
- Institute of Genetics and
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Fuxin Zhao
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Shuang Mei
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoxu Zhao
- Division of Medical Genetics and Genomics, Children’s Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, China
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiangtian Zhou
- School of Optometry and Ophthalmology and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Minglian Zhang
- Department of Ophthalmology, Hebei Provincial Eye Hospital, Xingtai, China
| | - Meng Wang
- Division of Medical Genetics and Genomics, Children’s Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, China
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Taosheng Huang
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Pingping Jiang
- Division of Medical Genetics and Genomics, Children’s Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, China
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
| | - Min-Xin Guan
- Division of Medical Genetics and Genomics, Children’s Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, China
- Institute of Genetics and
- Department of Human Genetics, Zhejiang University School of Medicine, Hangzhou, China
- Key Laboratory of Reproductive Genetics, Ministry of Education, Hangzhou, China
- Joint Institute of Genetics and Genomic Medicine, Zhejiang University and University of Toronto, Zhejiang University, Hangzhou, China
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25
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Shorey M, Stone MC, Mandel J, Rolls MM. Neurons survive simultaneous injury to axons and dendrites and regrow both types of processes in vivo. Dev Biol 2020; 465:108-118. [PMID: 32687893 DOI: 10.1016/j.ydbio.2020.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/09/2020] [Accepted: 07/10/2020] [Indexed: 12/11/2022]
Abstract
Neurons extend dendrites and axons to receive and send signals. If either type of process is removed, the cell cannot function. Rather than undergoing cell death, some neurons can regrow axons and dendrites. Axon and dendrite regeneration have been examined separately and require sensing the injury and reinitiating the correct growth program. Whether neurons in vivo can sense and respond to simultaneous axon and dendrite injury with polarized regeneration has not been explored. To investigate the outcome of simultaneous axon and dendrite damage, we used a Drosophila model system in which neuronal polarity, axon regeneration, and dendrite regeneration have been characterized. After removal of the axon and all but one dendrite, the remaining dendrite was converted to a process that had a long unbranched region that extended over long distances and a region where shorter branched processes were added. These observations suggested axons and dendrites could regrow at the same time. To further test the capacity of neurons to implement polarized regeneration after axon and dendrite damage, we removed all neurites from mature neurons. In this case a long unbranched neurite and short branched neurites were regrown from the stripped cell body. Moreover, the long neurite had axonal plus-end-out microtubule polarity and the shorter neurites had mixed polarity consistent with dendrite identity. The long process also accumulated endoplasmic reticulum at its tip like regenerating axons. We conclude that neurons in vivo can respond to simultaneous axon and dendrite injury by initiating growth of a new axon and new dendrites.
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Affiliation(s)
- Matthew Shorey
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Michelle C Stone
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Jenna Mandel
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA
| | - Melissa M Rolls
- Biochemistry and Molecular Biology and the Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, USA.
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26
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Iaboni DSM, Farrell SR, Chauhan BC. Morphological multivariate cluster analysis of murine retinal ganglion cells selectively expressing yellow fluorescent protein. Exp Eye Res 2020; 196:108044. [PMID: 32376469 DOI: 10.1016/j.exer.2020.108044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/10/2020] [Accepted: 04/25/2020] [Indexed: 10/24/2022]
Abstract
Optic neuropathies, such as glaucoma, lead to retinal ganglion cell (RGC) death. Transgenic mouse strains that express fluorescent proteins under the control of the Thy1 promoter have permitted single RGC imaging. Specifically, in one strain of mice expressing yellow fluorescent protein (Thy1-YFP), fluorescence is expressed in only 0.2% of RGCs. This reduced expression allows visualization of the full dendritic arbour of YFP-expressing RGCs, facilitating the investigation of structural changes. As susceptibility amongst RGCs varies with morphology and subtype, labelling methods should ideally non-discriminately label RGCs to accurately determine the effects of experimental glaucoma. This study therefore sought to determine morphological subtypes of RGCs in the Thy1-YFP mouse strain. Retinas from Thy1-YFP mice were imaged ex vivo with fluorescence microscopy. With Sholl analysis, a technique for quantifying the morphology of individual neurons, the dendritic field (DF), area under the curve (AUC), normalized AUC (Nav), peak number of intersections (PNI), and skew for single RGCs were computed. The distance of the RGC from the optic nerve head (dONH) was also measured. These morphological parameters were inputted into a multivariate cluster analysis to determine the optimal number of clusters to group all RGCs analyzed, which were then grouped into "Small", "Medium", and "Large" sized cluster groups according to increasing DF size. A total of 178 RGCs from 10 retinas of 8 mice were analyzed from which the cluster analysis identified 13 clusters. Eighty-eight (49%), 77 (43.2%), and 13 (7.3%) RGCs were grouped into small, medium and large clusters, respectively. Clusters 1-6 had small DFs. Clusters 1 and 3 had the lowest AUC and Nav. Clusters 2, 3, and 5 had asymmetric DFs while Clusters 3, 5, and 6 were distal to the ONH. Clusters 7-11 had medium DFs; of these, Clusters 7 and 10 had the lowest AUC, Clusters 8 and 10 had the highest skew, and Clusters 7 and 11 were closest to the ONH. Clusters 12 and 13 had large DFs. Both had low skew and high AUC. High PNI and dONH distinguished Cluster 12 from Cluster 13. We present the largest study to date examining YFP expression in RGCs of transgenic Thy1-YFP mice. Among the 13 clusters, there was a wide range of morphological features with further variation within size categories. Our findings support the notion that YFP is expressed non-discriminatingly in RGCs of Thy1-YFP transgenic mice and this strain is a valuable tool for studies of experimental optic neuropathies.
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Affiliation(s)
- Douglas S M Iaboni
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Sir Charles Tupper Medical Building 5850 College Street, B3H 4R2, Halifax, Nova Scotia, Canada; Dalhousie Medical School, Faculty of Medicine, Dalhousie University, Sir Charles Tupper Medical Building 5850 College Street, B3H 4R2, Halifax, Nova Scotia, Canada
| | - Spring R Farrell
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Sir Charles Tupper Medical Building 5850 College Street, B3H 4R2, Halifax, Nova Scotia, Canada; Department of Medical Neuroscience, Dalhousie University, Sir Charles Tupper Medical Building 5850 College Street, B3H 4R2, Halifax, Nova Scotia, Canada; Nova Scotia Health Authority, 1276 South Park Street, 2W Victoria, B3H 2Y9, Halifax, Nova Scotia, Canada
| | - Balwantray C Chauhan
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Sir Charles Tupper Medical Building 5850 College Street, B3H 4R2, Halifax, Nova Scotia, Canada; Department of Medical Neuroscience, Dalhousie University, Sir Charles Tupper Medical Building 5850 College Street, B3H 4R2, Halifax, Nova Scotia, Canada; Nova Scotia Health Authority, 1276 South Park Street, 2W Victoria, B3H 2Y9, Halifax, Nova Scotia, Canada; Department of Physiology and Biophysics, Dalhousie University, Sir Charles Tupper Medical Building 5850 College Street, B3H 4R2, Halifax, Nova Scotia, Canada; Department of Ophthalmology and Visual Sciences, Dalhousie University, 1276 South Park Street, 2W Victoria, B3H 2Y9, Halifax, Nova Scotia, Canada.
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Li L, Huang H, Fang F, Liu L, Sun Y, Hu Y. Longitudinal Morphological and Functional Assessment of RGC Neurodegeneration After Optic Nerve Crush in Mouse. Front Cell Neurosci 2020; 14:109. [PMID: 32410964 PMCID: PMC7200994 DOI: 10.3389/fncel.2020.00109] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 04/08/2020] [Indexed: 12/16/2022] Open
Abstract
The mouse optic nerve crush (ONC) model has been widely used to study optic neuropathies and central nervous system (CNS) axon injury and repair. Previous histological studies of retinal ganglion cell (RGC) somata in retina and axons in ON demonstrate significant neurodegeneration after ONC, but longitudinal morphological and functional assessment of RGCs in living animals is lacking. It is essential to establish these assays to provide more clinically relevant information for early detection and monitoring the progression of CNS neurodegeneration. Here, we present in vivo data gathered by scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), and pattern electroretinogram (PERG) at different time points after ONC in mouse eyes and corresponding histological quantification of the RGC somata and axons. Not surprisingly, direct visualization of RGCs by SLO fundus imaging correlated best with histological quantification of RGC somata and axons. Unexpectedly, OCT did not detect obvious retinal thinning until late time points (14 and 28-days post ONC) and instead detected significant retinal swelling at early time points (1–5 days post-ONC), indicating a characteristic initial retinal response to ON injury. PERG also demonstrated an early RGC functional deficit in response to ONC, before significant RGC death, suggesting that it is highly sensitive to ONC. However, the limited progression of PERG deficits diminished its usefulness as a reliable indicator of RGC degeneration.
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Affiliation(s)
- Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Fang Fang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States.,Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Liang Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
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Wu K, Lin C, Lam AKN, Chan L, Leung CKS. Wide-field Trend-based Progression Analysis of Combined Retinal Nerve Fiber Layer and Ganglion Cell Inner Plexiform Layer Thickness: A New Paradigm to Improve Glaucoma Progression Detection. Ophthalmology 2020; 127:1322-1330. [PMID: 32423768 DOI: 10.1016/j.ophtha.2020.03.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 03/06/2020] [Accepted: 03/16/2020] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVE Evaluation of glaucoma progression with OCT has been centered on the analysis of progressive retinal nerve fiber layer (RNFL) thinning over the parapapillary region and/or progressive ganglion cell inner plexiform layer (GCIPL) thinning over the macula. We investigated (1) whether combining the RNFL and GCIPL as a single layer (i.e., RNFL-GCIPL) for wide-field progression analysis outperforms wide-field progression analysis of the RNFL or the GCIPL, and (2) whether eyes with progressive RNFL-GCIPL thinning are at risk of visual field (VF) progression. DESIGN Prospective, longitudinal study. PARTICIPANTS A total of 440 eyes from 236 glaucoma patients; 98 eyes from 49 healthy individuals. METHODS OCT RNFL/GCIPL/RNFL-GCIPL thickness and VF measurements were obtained at ∼4-month intervals for ≥3 years. Progressive changes of the RNFL/GCIPL/RNFL-GCIPL thicknesses were analyzed over a wide field (12×9 mm2) covering the parapapillary region and the macula with trend-based progression analysis (TPA) controlled at a false discovery rate of 5%. VF progression was determined by the Early Manifest Glaucoma Trial criteria. MAIN OUTCOME MEASURES Proportions of eyes with progressive RNFL/GCIPL/RNFL-GCIPL thinning; hazard ratios (HRs) for development of VF progression. RESULTS More eyes showed progressive RNFL-GCIPL thinning (127 eyes; 28.9%, 95% confidence interval [CI]: 23.9%-33.8%) than progressive RNFL thinning (74 eyes; 16.8%, 95% CI: 13.1%-20.6%) and progressive GCIPL thinning (26 eyes; 5.9%, 95% CI: 3.7%-8.1%) in the glaucoma group over the study follow-up. Progressive RNFL-GCIPL thinning was almost always detected before or simultaneously with progressive RNFL thinning or progressive GCIPL thinning. The specificity of TPA (estimated from the healthy group) for detection of progressive RNFL-GCIPL thinning, progressive RNFL thinning, and progressive GCIPL thinning was 83.7% (95% CI: 74.9%-92.4%), 94.9% (95% CI: 90.6%-99.2%), and 96.9% (95% CI: 93.5%-100.0%), respectively. Eyes with progressive RNFL-GCIPL thinning had a higher risk to develop possible (HR: 2.4, 95% CI: 1.2-5.0) or likely (HR: 4.6, 95% CI: 1.5-14.0) VF progression, with adjustment of covariates, compared with eyes without progressive RNFL-GCIPL thinning. CONCLUSIONS Progression analysis of RNFL-GCIPL thickness reveals a significant portion of progressing eyes that neither progression analysis of RNFL thickness nor GCIPL thickness would identify. Wide-field progression analysis of RNFL-GCIPL thickness is effective to inform the risk of VF progression in glaucoma patients.
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Affiliation(s)
- Ken Wu
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Chen Lin
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Alexander Ka-Ngai Lam
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Leo Chan
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Christopher Kai-Shun Leung
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, People's Republic of China.
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29
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Mak HK, Ng SH, Ren T, Ye C, Leung CKS. Impact of PTEN/SOCS3 deletion on amelioration of dendritic shrinkage of retinal ganglion cells after optic nerve injury. Exp Eye Res 2020; 192:107938. [PMID: 31972211 DOI: 10.1016/j.exer.2020.107938] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 01/02/2020] [Accepted: 01/16/2020] [Indexed: 12/22/2022]
Abstract
Retinal ganglion cell (RGC) degeneration, leading to irreversible blindness in chronic optic neuropathies, commonly begins with dendritic shrinkage followed by axon degeneration. Although limited axon regeneration in the optic nerve is possible with a genetic deletion of PTEN/SOCS3 after optic nerve injury, the roles of PTEN/SOCS3 on dendritic preservation and regeneration remain unclear. This study investigated the effect of PTEN/SOCS3 genetic deletion on the structural integrity of RGC dendrites and axons in the retina following optic nerve crush. Using time-lapse, in vivo confocal scanning laser ophthalmoscopy to serially image dendritic and axonal arborizations of RGCs over six months after injury, RGC dendrites and axons were only preserved in Thy-1-YFP/PTEN-/- and Thy-1-YFP/PTEN-/-SOCS3-/- mice, and axons in the retina regenerated at a rate of 21.1 μm/day and 15.5 μm/day, respectively. By contrast, dendritic complexity significantly decreased in Thy-1-YFP-SOCS3-/- and control mice at a rate of 7.0 %/day and 7.1 %/day, respectively, and no axon regeneration in the retina was observed. RGC survival probability was higher in Thy-1-YFP/PTEN-/- and Thy-1-YFP/PTEN-/-SOCS3-/- mice compared with Thy-1-YFP-SOCS3-/- and control mice. The differential responses between the transgenic mice demonstrate that although a genetic deletion of PTEN, SOCS3, or PTEN/SOCS3 allows partial axon regeneration in the optic nerve after optic nerve crush, a deletion of PTEN, but not SOCS3, ameliorates RGC dendritic shrinkage. This shows that the signaling pathways involved in promoting axon regeneration do not equally contribute to the preservation of dendrites, which is crucial to the translational application of neuroregenerative therapies for visual restoration.
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Affiliation(s)
- Heather K Mak
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
| | - Shuk Han Ng
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
| | - Tianmin Ren
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
| | - Cong Ye
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
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30
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Tribble JR, Vasalauskaite A, Redmond T, Young RD, Hassan S, Fautsch MP, Sengpiel F, Williams PA, Morgan JE. Midget retinal ganglion cell dendritic and mitochondrial degeneration is an early feature of human glaucoma. Brain Commun 2019; 1:fcz035. [PMID: 31894207 PMCID: PMC6928391 DOI: 10.1093/braincomms/fcz035] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/29/2019] [Accepted: 11/01/2019] [Indexed: 12/31/2022] Open
Abstract
Glaucoma is characterized by the progressive dysfunction and loss of retinal ganglion cells. However, the earliest degenerative events that occur in human glaucoma are relatively unknown. Work in animal models has demonstrated that retinal ganglion cell dendrites remodel and atrophy prior to the loss of the cell soma. Whether this occurs in human glaucoma has yet to be elucidated. Serial block face scanning electron microscopy is well established as a method to determine neuronal connectivity at high resolution but so far has only been performed in normal retina from animal models. To assess the structure-function relationship of early human glaucomatous neurodegeneration, regions of inner retina assessed to have none-to-moderate loss of retinal ganglion cell number were processed using serial block face scanning electron microscopy (n = 4 normal retinas, n = 4 glaucoma retinas). This allowed detailed 3D reconstruction of retinal ganglion cells and their intracellular components at a nanometre scale. In our datasets, retinal ganglion cell dendrites degenerate early in human glaucoma, with remodelling and redistribution of the mitochondria. We assessed the relationship between visual sensitivity and retinal ganglion cell density and discovered that this only partially conformed to predicted models of structure-function relationships, which may be affected by these early neurodegenerative changes. In this study, human glaucomatous retinal ganglion cells demonstrate compartmentalized degenerative changes as observed in animal models. Importantly, in these models, many of these changes have been demonstrated to be reversible, increasing the likelihood of translation to viable therapies for human glaucoma.
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Affiliation(s)
- James R Tribble
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ Wales, UK
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, 112 82 Stockholm, Sweden
| | | | - Tony Redmond
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ Wales, UK
| | - Robert D Young
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ Wales, UK
| | - Shoaib Hassan
- School of Medicine, Cardiff University, Heath Park, Cardiff, CF14 4XW Wales, UK
| | | | - Frank Sengpiel
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX Wales, UK
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, 112 82 Stockholm, Sweden
| | - James E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Cardiff, CF24 4HQ Wales, UK
- School of Medicine, Cardiff University, Heath Park, Cardiff, CF14 4XW Wales, UK
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31
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Agostinone J, Alarcon-Martinez L, Gamlin C, Yu WQ, Wong ROL, Di Polo A. Insulin signalling promotes dendrite and synapse regeneration and restores circuit function after axonal injury. Brain 2019; 141:1963-1980. [PMID: 29931057 PMCID: PMC6022605 DOI: 10.1093/brain/awy142] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/06/2018] [Indexed: 01/07/2023] Open
Abstract
Dendrite pathology and synapse disassembly are critical features of chronic neurodegenerative diseases. In spite of this, the capacity of injured neurons to regenerate dendrites has been largely ignored. Here, we show that, upon axonal injury, retinal ganglion cells undergo rapid dendritic retraction and massive synapse loss that preceded neuronal death. Human recombinant insulin, administered as eye drops or systemically after dendritic arbour shrinkage and prior to cell loss, promoted robust regeneration of dendrites and successful reconnection with presynaptic targets. Insulin-mediated regeneration of excitatory postsynaptic sites on retinal ganglion cell dendritic processes increased neuronal survival and rescued light-triggered retinal responses. Further, we show that axotomy-induced dendrite retraction triggered substantial loss of the mammalian target of rapamycin (mTOR) activity exclusively in retinal ganglion cells, and that insulin fully reversed this response. Targeted loss-of-function experiments revealed that insulin-dependent activation of mTOR complex 1 (mTORC1) is required for new dendritic branching to restore arbour complexity, while complex 2 (mTORC2) drives dendritic process extension thus re-establishing field area. Our findings demonstrate that neurons in the mammalian central nervous system have the intrinsic capacity to regenerate dendrites and synapses after injury, and provide a strong rationale for the use of insulin and/or its analogues as pro-regenerative therapeutics for intractable neurodegenerative diseases including glaucoma.
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Affiliation(s)
- Jessica Agostinone
- Department of Neuroscience, University of Montreal, Montreal, Quebec, Canada.,University of Montreal Hospital Research Center (CR-CHUM), University of Montreal, Montreal, Quebec, Canada
| | - Luis Alarcon-Martinez
- Department of Neuroscience, University of Montreal, Montreal, Quebec, Canada.,University of Montreal Hospital Research Center (CR-CHUM), University of Montreal, Montreal, Quebec, Canada
| | - Clare Gamlin
- Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, Washington, USA
| | - Wan-Qing Yu
- Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, Washington, USA
| | - Rachel O L Wong
- Department of Biological Structure, University of Washington, 1959 NE Pacific Street, Seattle, Washington, USA
| | - Adriana Di Polo
- Department of Neuroscience, University of Montreal, Montreal, Quebec, Canada.,University of Montreal Hospital Research Center (CR-CHUM), University of Montreal, Montreal, Quebec, Canada
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32
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Blandford SN, Hooper ML, Yabana T, Chauhan BC, Baldridge WH, Farrell SRM. Retinal Characterization of the Thy1-GCaMP3 Transgenic Mouse Line After Optic Nerve Transection. Invest Ophthalmol Vis Sci 2019; 60:183-191. [PMID: 30640971 DOI: 10.1167/iovs.18-25861] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose GCaMP3 is a genetically encoded calcium indicator for monitoring intracellular calcium dynamics. We characterized the expression pattern and functional properties of GCaMP3 in the Thy1-GCaMP3 transgenic mouse retina. Methods To determine the specificity of GCaMP3 expression, Thy1-GCaMP3 (B6; CBA-Tg(Thy1-GCaMP3)6Gfng/J) retinas were processed for immunohistochemistry with anti-green fluorescent protein (anti-GFP, to enhance GCaMP3 fluorescence), anti-RBPMS (retinal ganglion cell [RGC]-specific marker), and antibodies against amacrine cell markers (ChAT, GABA, GAD67, syntaxin). Calcium imaging was used to characterize functional responses of GCaMP3-expressing (GCaMP+) cells by recording calcium transients evoked by superfusion of kainic acid (KA; 10, 50, or 100 μM). In a subset of animals, optic nerve transection (ONT) was performed 3, 5, or 7 days prior to calcium imaging. Results GFP immunoreactivity colocalized with RBPMS but not amacrine cell markers in both ONT and non-ONT (control) groups. Calcium transients evoked by KA were reduced after ONT (50 μM KA; ΔF/F0 [SD]; control: 1.00 [0.67], day 3: 0.50 [0.35], day 5: 0.31 [0.28], day 7: 0.35 [0.36]; P < 0.05 versus control). There was also a decrease in the number of GCaMP3+ cells after ONT (cells/mm2 [SD]; control: 2198 [453], day 3: 2224 [643], day 5: 1383 [375], day 7: 913 [178]; P < 0.05). Furthermore, the proportion of GCaMP3+ cells that responded to KA decreased after ONT (50 μM KA, 97%, 54%, 47%, and 58%; control, 3, 5, and 7 days, respectively). Conclusions Following ONT, functional RGC responses are lost prior to the loss of RGC somata, suggesting that anatomical markers of RGCs may underestimate the extent of RGC dysfunction.
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Affiliation(s)
- Stephanie N Blandford
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada.,Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michele L Hooper
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Takeshi Yabana
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada.,Tohoku University Graduate School of Medicine, Department of Ophthalmology, Sendai, Japan
| | - Balwantray C Chauhan
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada.,Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada.,Nova Scotia Health Authority, Halifax, Nova Scotia, Canada
| | - William H Baldridge
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada.,Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Spring R M Farrell
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada.,Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada.,Nova Scotia Health Authority, Halifax, Nova Scotia, Canada
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An in vitro pressure model towards studying the response of primary retinal ganglion cells to elevated hydrostatic pressures. Sci Rep 2019; 9:9057. [PMID: 31227762 PMCID: PMC6588599 DOI: 10.1038/s41598-019-45510-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/04/2019] [Indexed: 01/09/2023] Open
Abstract
Glaucoma is a leading cause of blindness characterized by progressive degeneration of retinal ganglion cells (RGCs). A well-established risk factor for the development and progression of glaucoma is elevation of intraocular pressure (IOP). However, how elevated IOP leads to RGC degeneration remains poorly understood. Here, we fabricate a facile, tunable hydrostatic pressure platform to study the effect of increased hydrostatic pressure on RGC axon and total neurite length, cell body area, dendritic branching, and cell survival. The hydrostatic pressure can be adjusted by varying the height of a liquid reservoir attached to a three-dimensional (3D)-printed adapter. The proposed platform enables long-term monitoring of primary RGCs in response to various pressure levels. Our results showed pressure-dependent changes in the axon length, and the total neurite length. The proportion of RGCs with neurite extensions significantly decreased by an average of 38 ± 2% (mean ± SEM) at pressures 30 mmHg and above (p < 0.05). The axon length and total neurite length decreased at a rate of 1.65 ± 0.18 μm and 4.07 ± 0.34 μm, respectively (p < 0.001), for each mmHg increase in pressure after 72 hours pressure treatment. Dendritic branching increased by 0.20 ± 0.05 intersections/day at pressures below 25 mmHg, and decreased by 0.07 ± 0.01 intersections/day at pressures above 25 mmHg (p < 0.001). There were no significant changes in cell body area under different levels of hydrostatic pressure (p ≥ 0.05). Application of this model will facilitate studies on the biophysical mechanisms that contribute to the pathophysiology of glaucoma and provide a channel for the screening of potential pharmacological agents for neuroprotection.
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34
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Factors governing the transduction efficiency of adeno-associated virus in the retinal ganglion cells following intravitreal injection. Gene Ther 2019; 26:109-120. [PMID: 30692605 DOI: 10.1038/s41434-019-0060-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 12/20/2018] [Accepted: 12/26/2018] [Indexed: 02/08/2023]
Abstract
Efficient transduction of the retinal ganglion cells (RGCs) is a prerequisite to maximize therapeutic outcomes in any form of gene therapy for optic neuropathies. Whereas subretinal injection of adeno-associated virus 2 (AAV2) has been well-characterized, the serotype, viral load, and promoter combinations that govern RGC transduction efficiency following intravitreal injection remains poorly understood. We evaluated the transduction efficiency of seven AAV2 serotypes (AAV2/1, AAV2/2, AAV2/4, AAV2/5, AAV2/6, AAV2/8, and AAV2/9) for the RGCs at 4 weeks following intravitreal injection in C57BL/6J mice. Intravitreal injection of 1 × 109 vg of AAV2/2 with eGFP driven by the CMV promoter attained a higher transduction efficiency for the RGCs (60.0 ± 4.2%) compared with the six other AAV2 serotypes with eGFP driven by the same promoter injected at the same viral load ( < 3.0%). Reporter driven by the CAG promoter had a lower transduction efficiency (up to 42.0 ± 5.8%) compared with that driven by the CMV reporter (60.0 ± 4.2%, p ≤ 0.024). There was a viral dose-dependent transduction effect of AAV2/2-CMV-eGFP and the transduction efficiency was 40.2 ± 3.9%, 16.6 ± 4.2%, and 2.6 ± 0.2% when the viral load decreased to 5 × 108 vg, 1 × 108 vg, and 1 × 107 vg, respectively. Optimizing viral serotype, viral load, and promoter construct of AAV2 is important to maximize transgene expression in RGC-targeted gene therapy.
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Abstract
Retinal ganglion cells (RGCs) that express the photopigment melanopsin (mRGCs) are photosensitive and initiate the non-image-forming pathway, where the majority of their axons terminate in the suprachiasmatic nucleus (SCN). RGCs only make up approximately half of the cells in the ganglion cell layer of the retina; therefore, it is important to be able to distinguish them from other cell types. The transgenic Thy-1 YFP mouse line 16 (Thy-1 YFP-16) expresses yellow-fluorescent protein (YFP) in projection neurons, including RGCs. Our objective was to determine whether mRGCs are labeled with YFP in Thy-1 YFP-16 transgenic mice. Paraformaldehyde-fixed retinal wholemounts and frozen vertical sections were prepared from Thy-1 YFP-16 mice and fluorescently labeled with rabbit anti-melanopsin and guinea-pig anti-RNA binding protein with multiple splicing to identify mRGCs and total RGCs, respectively. Thy-1 YFP-16 mouse brains were sectioned coronally and imaged to view RGC axonal projections to the SCN. Confocal images of retinal preparations show that the majority (∼89%) of mRGCs are not YFP-positive in Thy-1 YFP-16 mice, where ∼11% expressed a weak fluorescent signal. In addition, there are almost no YFP-positive axons present in the SCN of coronal brain sections. We conclude that the majority of mRGC somas and axons are not labeled with YFP in the transgenic Thy-1 YFP-16 mouse line; therefore, this mouse model may not suitable for research involving mRGC visual pathways.
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Fry LE, Fahy E, Chrysostomou V, Hui F, Tang J, van Wijngaarden P, Petrou S, Crowston JG. The coma in glaucoma: Retinal ganglion cell dysfunction and recovery. Prog Retin Eye Res 2018; 65:77-92. [DOI: 10.1016/j.preteyeres.2018.04.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/18/2018] [Accepted: 04/03/2018] [Indexed: 01/07/2023]
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Kimball EC, Jefferys JL, Pease ME, Oglesby EN, Nguyen C, Schaub J, Pitha I, Quigley HA. The effects of age on mitochondria, axonal transport, and axonal degeneration after chronic IOP elevation using a murine ocular explant model. Exp Eye Res 2018; 172:78-85. [PMID: 29625080 PMCID: PMC5994189 DOI: 10.1016/j.exer.2018.04.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/07/2018] [Accepted: 04/02/2018] [Indexed: 01/03/2023]
Abstract
The purpose of this study was to compare younger and older mice after chronic intraocular pressure (IOP) elevation lasting up to 4 days with respect to mitochondrial density, structure, and movement, as well as axonal integrity, in an ex vivo explant model. We studied 2 transgenic mouse strains, both on a C57BL/6J background, one expressing yellow fluorescent protein (YFP) in selected axons and one expressing cyan fluorescent protein (CFP) in all mitochondria. Mice of 4 months or 14 months of age were exposed to chronic IOP by anterior chamber microbead injection for 14 h, 1, 3, or 4 days. The optic nerve head of globe--optic nerve explants were examined by laser scanning microscopy. Mitochondrial density, structure, and movement were quantified in the CFP explants, and axonal integrity was quantified in YFP explants. In control mice, there was a trend towards decreased mitochondrial density (# per mm2) with age when comparing younger to older, control mice, but this was not significant (1947 ± 653 vs 1412 ± 356; p = 0.19). Mitochondrial density decreased after IOP elevation, significantly, by 31%, in younger mice (p = 0.04) but trending towards a decrease, by 22%, in older mice (p = 0.82) compared to age matched controls. Mitochondrial mean size was not altered after chronic IOP elevation for 14 h or more (p ≥ 0.16). When assessing mitochondrial movement, in younger mice, 5% were mobile at any given time; 4% in the anterograde direction and 1% retrograde. In younger untreated tissue, only 75% of explants had moving mitochondria (mean = 15.8 moving/explant), while after glaucoma induction only 24% of explants had moving mitochondria (mean = 4.2 moving/explant; difference from control, p = 0.03). The distance mitochondria traveled in younger mice was unchanged after glaucoma exposure, but in older glaucoma explants the distance traveled was less than half of older controls (p < 0.0003). In younger mice, mitochondrial speed increased after 14 h of elevated IOP (p = 0.006); however, in older glaucoma explants, movement was actually slower than controls (p = 0.02). In RGC-YFP explants, axonal integrity declined significantly after 4 days of IOP elevation to a similar degree in both younger and older mice. Older mice underwent greater loss of mitochondrial movement with chronic IOP elevation than younger mice, but suffered similar short-term axonal fragmentation in C57BL/6J mice. These transgenic strains, studied in explants, permit observations of alterations in intracellular structure and organelle activity in experimental glaucoma.
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Affiliation(s)
- Elizabeth C Kimball
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA.
| | - Joan L Jefferys
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Mary E Pease
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Ericka N Oglesby
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Cathy Nguyen
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Julie Schaub
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Ian Pitha
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; The Center for Nanomedicine, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Harry A Quigley
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
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Huang XR, Kong W, Qiao J. Response of the Retinal Nerve Fiber Layer Reflectance and Thickness to Optic Nerve Crush. Invest Ophthalmol Vis Sci 2018; 59:2094-2103. [PMID: 29677373 PMCID: PMC5912800 DOI: 10.1167/iovs.17-23148] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 03/13/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose To study the effects of acute optic nerve damage on the reflectance of the retinal nerve fiber layer (RNFL) and to compare the time courses of changes of RNFL reflectance and thickness. Methods A rat model of optic nerve crush (ONC) was compared with previously studied normal retinas. The reflectance and thickness of the RNFL were studied at 1 to 5 weeks after ONC. Reflectance spectra from 400 to 830 nm were measured for eyes with ONC, their contralateral untreated eyes, and eyes with sham surgery. Directional reflectance was studied by varying the angle of light incidence. RNFL thickness was measured by confocal microscopy. Results After ONC, the RNFL reflectance remained directional. At 1 week, RNFL reflectance decreased significantly at all wavelengths (P < 0.001), whereas there was no significant change in RNFL thickness (P = 0.739). At 2 weeks, both RNFL reflectance and thickness decreased significantly, and by 5 weeks they declined to approximately 40% and 30%, respectively, of the normal values. Although RNFL reflectance decreased at all wavelengths, there was a greater reduction at short wavelengths. Spectral shape at long wavelengths was similar to the normal. Some of these changes were also found in the contralateral untreated eyes, but none of these changes were found in eyes with sham surgery. Conclusions Decrease of RNFL reflectance after ONC occurs prior to thinning of the RNFL and the decrease is more prominent at short wavelengths. Direct measurement of RNFL reflectance, especially at short wavelengths, may provide early detection of axonal damage.
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Affiliation(s)
- Xiang-Run Huang
- Bascom Palmer Eye Institute, Miller School of Medicine University of Miami, Miami, Florida, United States
| | - Wei Kong
- Bascom Palmer Eye Institute, Miller School of Medicine University of Miami, Miami, Florida, United States
| | - Jianzhong Qiao
- Bascom Palmer Eye Institute, Miller School of Medicine University of Miami, Miami, Florida, United States
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Integrating Macular Ganglion Cell Inner Plexiform Layer and Parapapillary Retinal Nerve Fiber Layer Measurements to Detect Glaucoma Progression. Ophthalmology 2018; 125:822-831. [PMID: 29433852 DOI: 10.1016/j.ophtha.2017.12.027] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 12/02/2017] [Accepted: 12/19/2017] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To investigate the temporal relationship among progressive macular ganglion cell inner plexiform layer (GCIPL) thinning, progressive parapapillary retinal nerve fiber layer (RNFL) thinning, and visual field (VF) progression in patients with primary open-angle glaucoma (POAG). DESIGN Prospective study. PARTICIPANTS One hundred thirty-six POAG patients (231 eyes) followed up for ≥5 years. METHODS OCT imaging of the macular GCIPL and parapapillary RNFL and perimetry were performed at ∼ 4-month intervals. Progressive GCIPL and RNFL thinning were determined by Guided Progression Analysis (GPA) of serial GCIPL and RNFL thickness maps. The specificities of GPA were calculated from the proportions of eyes with progressive GCIPL or RNFL thinning in 67 eyes of 36 healthy individuals followed up for ≥5 years. Visual field progression (likely or possible) was determined by the Early Manifest Glaucoma Trial criteria. MAIN OUTCOME MEASURES Hazard ratios for VF progression, progressive RNFL thinning, and progressive GCIPL thinning, as determined by time-varying Cox models. RESULTS GPA detected 57 eyes (24.7%) with progressive GCIPL thinning and 66 eyes (28.6%) with progressive RNFL thinning at a specificity of 95.5% and 91.0%, respectively. Thirty-five eyes (15.2%) demonstrated progressive RNFL and GCIPL thinning, whereas 53 eyes (22.9%) demonstrated progressive RNFL or GCIPL thinning. Eyes with progressive GCIPL thinning had a higher risk for progressive RNFL thinning (HR, 5.27; 95% confidence interval [CI], 2.89-9.62), whereas eyes with progressive RNFL thinning were also at a higher risk for progressive GCIPL thinning (HR, 2.99; 95% CI, 1.48-6.02), after adjusting for baseline covariates. The HRs for likely and possible VF progression were 3.48 (95% CI, 1.51-8.01) and 2.74 (95% CI, 1.26-5.98), respectively, on detection of progressive GCIPL thinning and 3.66 (95% CI, 1.68-7.97) and 2.54 (95% CI, 1.23-5.21), respectively, on detection of progressive RNFL thinning after adjusting for baseline covariates. Eyes with VF progression were not at risk of progressive RNFL or GCIPL thinning (P ≥ 0.493). CONCLUSIONS Progressive macular GCIPL thinning and progressive parapapillary RNFL thinning are mutually predictive. Because progressive RNFL thinning and progressive GCIPL thinning are both indicative of VF progression, integrating macular GCIPL and parapapillary RNFL measurements is relevant to facilitate early detection of disease deterioration in glaucoma patients.
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Nickells RW, Schmitt HM, Maes ME, Schlamp CL. AAV2-Mediated Transduction of the Mouse Retina After Optic Nerve Injury. Invest Ophthalmol Vis Sci 2017; 58:6091-6104. [PMID: 29204649 PMCID: PMC5716181 DOI: 10.1167/iovs.17-22634] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Purpose Gene therapy of retinal ganglion cells (RGCs) has promise as a powerful therapeutic for the rescue and regeneration of these cells after optic nerve damage. However, early after damage, RGCs undergo atrophic changes, including gene silencing. It is not known if these changes will deleteriously affect transduction and transgene expression, or if the therapeutic protein can influence reactivation of the endogenous genome. Methods Double-transgenic mice carrying a Rosa26-(LoxP)-tdTomato reporter, and a mutant allele for the proapoptotic Bax gene were reared. The Bax mutant blocks apoptosis, but RGCs still exhibit nuclear atrophy and gene silencing. At times ranging from 1 hour to 4 weeks after optic nerve crush (ONC), eyes received an intravitreal injection of AAV2 virus carrying the Cre recombinase. Successful transduction was monitored by expression of the tdTomato reporter. Immunostaining was used to localize tdTomato expression in select cell types. Results Successful transduction of RGCs was achieved at all time points after ONC using AAV2 expressing Cre from the phosphoglycerate kinase (Pgk) promoter, but not the CMV promoter. ONC promoted an increase in the transduction of cell types in the inner nuclear layer, including Müller cells and rod bipolar neurons. There was minimal evidence of transduction of amacrine cells and astrocytes in the inner retina or optic nerve. Conclusions Damaged RGCs can be transduced and at least some endogenous genes can be subsequently activated. Optic nerve damage may change retinal architecture to allow greater penetration of an AAV2 virus to transduce several additional cell types in the inner nuclear layer.
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Affiliation(s)
- Robert W Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Heather M Schmitt
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States.,Cellular and Molecular Pathology Graduate Program, University of Wisconsin-Madison, Madison, Wisconsin, United States
| | - Margaret E Maes
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States.,Institute of Science and Technology Austria, Klosterneurberg, Austria
| | - Cassandra L Schlamp
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States
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Miyake S, Takihara Y, Yokota S, Takamura Y, Inatani M. Effect of Microtubule Disruption on Dynamics of Acidic Organelles in the Axons of Primary Cultured Retinal Ganglion Cells. Curr Eye Res 2017; 43:77-83. [PMID: 28937869 DOI: 10.1080/02713683.2017.1370117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
PURPOSE Axonal transport is fundamental to autophagy in neuronal cells. To understand its biological significance in various conditions, it is necessary to monitor the process of autophagy. However, monitoring methods are often limited to static analyses, such as protein expression and histological observations. Autophagy has multistep process and is highly dynamic; therefore, additional techniques are necessary to study autophagy. In this study, we quantified the dynamics of autophagy-related organelle transport under conditions of dynamic instability and catastrophic disruption of microtubules using in vitro live imaging. MATERIALS AND METHODS Retinal ganglion cells (RGCs) were isolated from postnatal day 3 Sprague-Dawley rats by immunopanning. After 7 days of culture, acidic organelles were stained by LysoTracker. Dynamics of acidic organelles was quantified using kymographs. Colchicine was used to induce microtubule disruption. Movement of acidic organelles was observed at five time points: before, and at 6, 24, 72, and 120 h after colchicine stimulation. Ethidium homodimer-1 (EthD-1) was used to determine cell viability. RESULTS The status of axonal transport of acidic organelles (n = 363) from 27 RGCs was classified into four categories: anterograde (1.4%), retrograde (90%), stationary (8.0%), and fluttering (0.28%). Six hours after the induction of microtubule disruption in 14 of 27 RGCs, almost all acidic organelles (n = 236) were stationary. All acidic components had completely stopped moving 24 h later. At 72 h after stimulation, axonal fragmentation, and shrinking and disappearance of soma were observed in 71% of RGCs. Finally, the remaining RGCs became positive for EthD-1. In the control (13 of 27 RGCs), axonal transport was maintained for 120 h and EthD-1-positive RGCs were not observed. CONCLUSION Almost all acidic organelles were transported retrogradely along the axon, which was inhibited by colchicine. Understanding the dynamics of acidic organelles may provide useful parameters for characterizing autophagy of neuronal cells in pathophysiological conditions.
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Affiliation(s)
- Seiji Miyake
- a Department of Ophthalmology, Faculty of Medical Sciences , University of Fukui , Fukui , Japan
| | - Yuji Takihara
- a Department of Ophthalmology, Faculty of Medical Sciences , University of Fukui , Fukui , Japan.,b Cancer Science Institute of Singapore , National University of Singapore , Medical Drive , Singapore
| | - Satoshi Yokota
- a Department of Ophthalmology, Faculty of Medical Sciences , University of Fukui , Fukui , Japan.,c Department of Ophthalmology and Visual Sciences , Kyoto University Graduate School of Medicine , Kyoto , Japan
| | - Yoshihiro Takamura
- a Department of Ophthalmology, Faculty of Medical Sciences , University of Fukui , Fukui , Japan
| | - Masaru Inatani
- a Department of Ophthalmology, Faculty of Medical Sciences , University of Fukui , Fukui , Japan
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Cholinergic Potentiation of Restoration of Visual Function after Optic Nerve Damage in Rats. Neural Plast 2017; 2017:6928489. [PMID: 28928986 PMCID: PMC5592016 DOI: 10.1155/2017/6928489] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 05/26/2017] [Accepted: 06/04/2017] [Indexed: 01/03/2023] Open
Abstract
Enhancing cortical plasticity and brain connectivity may improve residual vision following a visual impairment. Since acetylcholine plays an important role in attention and neuronal plasticity, we explored whether potentiation of the cholinergic transmission has an effect on the visual function restoration. To this end, we evaluated for 4 weeks the effect of the acetylcholinesterase inhibitor donepezil on brightness discrimination, visually evoked potentials, and visual cortex reactivity after a bilateral and partial optic nerve crush in adult rats. Donepezil administration enhanced brightness discrimination capacity after optic nerve crush compared to nontreated animals. The visually evoked activation of the primary visual cortex was not restored, as measured by evoked potentials, but the cortical neuronal activity measured by thallium autometallography was not significantly affected four weeks after the optic nerve crush. Altogether, the results suggest a role of the cholinergic system in postlesion cortical plasticity. This finding agrees with the view that restoration of visual function may involve mechanisms beyond the area of primary damage and opens a new perspective for improving visual rehabilitation in humans.
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Dailey WA, Drenser KA, Wong SC, Cheng M, Vercellone J, Roumayah KK, Feeney EV, Deshpande M, Guzman AE, Trese M, Mitton KP. Norrin treatment improves ganglion cell survival in an oxygen-induced retinopathy model of retinal ischemia. Exp Eye Res 2017; 164:129-138. [PMID: 28823941 DOI: 10.1016/j.exer.2017.08.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 07/17/2017] [Accepted: 08/14/2017] [Indexed: 12/25/2022]
Abstract
Treatment of a mouse model of oxygen-induced retinopathy (OIR) with recombinant human Norrin (Norrie Disease Protein, gene: NDP) accelerates regrowth of the microvasculature into central ischemic regions of the neural retina, which are generated after treatment with 75% oxygen. While this reduces the average duration and severity of ischemia overall, we do not know if this accelerated recovery of the microvasculature results in any significant survival of retinal ganglion cells (RGCs). The purpose of this study was to investigate ganglion cell survival with and without the intravitreal injection of Norrin in the murine model of oxygen induced retinopathy (OIR), using two strains of mice: C57BL/6J and Thy1-YFP mice. Intravitreal injections of Norrin or vehicle were done after five days of exposure to 75% oxygen from ages P7 to P12. The C57BL/J mice were followed by Spectral-Domain Optical Coherence Tomography (SD-OCT), and the average nerve fiber layer (NFL) and inner-plexiform layer (IPL) thicknesses were measured at twenty-four locations per retina at P42. Additionally, some C57BL/J retinas were flat mounted and immunostained for the RGC marker, Brn3a, to compare the population density of surviving retinal ganglion cells. Using homozygous Thy1-YFP mice, single intrinsically fluorescent RGCs were imaged in live animals with a Micron-III imaging system at ages P21, 28 and P42. The relative percentage of YFP-fluorescent RGCs with dendritic arbors were compared. At age P42, the NFL was thicker in Norrin-injected OIR eyes, 14.4 μm, compared to Vehicle-injected OIR eyes, 13.3 μm (p = 0.01). In the superior retina, the average thickness of the IPL was greater in Norrin-injected OIR eyes, 37.7 μm, compared to Vehicle-injected OIR eyes, 34.6 μm (p = 0.04). Retinas from Norrin injected OIR mice had significantly more surviving RGCs (p = 0.03) than vehicle-injected mice. Based upon NFL thickness and counts of RGCs, we conclude that Norrin treatment, early in the ischemic phase, increased the relative population density of surviving RGCs in the central retinas of OIR mice.
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Affiliation(s)
- Wendy A Dailey
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Kimberly A Drenser
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States; Associated Retinal Consultants, Novi, MI, United States
| | - Sui Chien Wong
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Mei Cheng
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Joseph Vercellone
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Kevin K Roumayah
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Erin V Feeney
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States
| | - Mrinalini Deshpande
- Control of Gene Expression Laboratory, Eye Research Institute, Oakland University, United States
| | - Alvaro E Guzman
- Control of Gene Expression Laboratory, Eye Research Institute, Oakland University, United States
| | - Michael Trese
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States; Associated Retinal Consultants, Novi, MI, United States
| | - Kenneth P Mitton
- Pediatric Retinal Research Laboratory, Eye Research Institute, Oakland University, Rochester Hills, MI 48309, United States; Control of Gene Expression Laboratory, Eye Research Institute, Oakland University, United States.
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Feng L, Chen H, Yi J, Troy JB, Zhang HF, Liu X. Long-Term Protection of Retinal Ganglion Cells and Visual Function by Brain-Derived Neurotrophic Factor in Mice With Ocular Hypertension. Invest Ophthalmol Vis Sci 2017; 57:3793-802. [PMID: 27421068 PMCID: PMC4961002 DOI: 10.1167/iovs.16-19825] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Purpose Glaucoma, frequently associated with elevated intraocular pressure (IOP), is characterized by progressive retinal ganglion cell (RGC) death and vision loss. Brain-derived neurotrophic factor (BDNF) has been studied as a candidate for neuroprotection in rodent models of experimental glaucoma, yet it remains to be determined whether BDNF exerts long-term protection for subtype RGCs and vision against chronic IOP elevation. Methods We induced modest and sustained IOP elevation by laser illumination and microbead injection in mice. Using a tamoxifen-induced Cre recombinase system, BDNF was upregulated in the mouse retina when sustained IOP elevation was induced. We then examined whether overexpression of BDNF protected RGCs and vision during the period of ocular hypertension. Given that BDNF modulates axon growth and dendritic formation in a subtype-dependent manner, we tested whether BDNF protects RGC dendritic structure against the hypertensive insult also in a subtype-dependent manner. Results Sustained IOP elevation was induced and lasted up to 6 months. Overexpression of BDNF delayed progressive RGC and axon loss in hypertensive eyes. Brain-derived neurotrophic factor overexpression also helped to preserve acuity against the chronic hypertensive insult. We classified RGCs into ON and ON–OFF subtypes based on their dendritic lamination pattern in the inner plexiform layer and found that BDNF prevented ON–RGC dendritic degeneration in mice with sustained ocular hypertension. Conclusions Our data demonstrated that BDNF can protect the dendritic fields of ON RGCs and reduce RGC and vision loss in mice with sustained ocular hypertension.
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Affiliation(s)
- Liang Feng
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States 2Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, Illinois, United States
| | - Hui Chen
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States
| | - Ji Yi
- Department of Biomedical Engineering, Robert R. McCormick School of Engineering and Applied Science, Northwestern University, Evanston, Illinois, United States
| | - John B Troy
- Department of Biomedical Engineering, Robert R. McCormick School of Engineering and Applied Science, Northwestern University, Evanston, Illinois, United States
| | - Hao F Zhang
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States 3Department of Biomedical Engineering, Robert R. McCormick School of Engineering and Applied Science, Northwestern University, Evanston, Il
| | - Xiaorong Liu
- Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States 2Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, Illinois, United States
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Li ST, Wang XN, Du XH, Wu Q. Comparison of spectral-domain optical coherence tomography for intra-retinal layers thickness measurements between healthy and diabetic eyes among Chinese adults. PLoS One 2017; 12:e0177515. [PMID: 28493982 PMCID: PMC5426752 DOI: 10.1371/journal.pone.0177515] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 04/29/2017] [Indexed: 12/02/2022] Open
Abstract
PURPOSE To compare intra-retinal layer thickness measurements between eyes with no or mild diabetic retinopathy (DR) and age-matched controls using Spectralis spectral-domain optical coherence tomography (SD-OCT). METHODS Cross-sectional observational analysis study. High-resolution macular volume scans (30° * 25°) were obtained for 133 type 2 diabetes mellitus (T2DM) patients with no DR, 42 T2DM patients with mild DR and 115 healthy controls. The mean thickness was measured in all 9 Early Treatment Diabetic Retinopathy Study (ETDRS) sectors for 8 separate layers, inner retinal layer (IRL), outer retinal layer (ORL) and total retina (TR), after automated segmentation. The ETDRS grid consisted of three concentric circles of 1-, 3-, and 6-mm diameter. The superior, inferior, temporal, and nasal sectors of the 3- and 6-mm circles were respectively designated as S3, I3, T3, and N3 and S6, I6, T6, and N6. Linear regression analyses were conducted to evaluate the associations between the intra-retinal layer thicknesses, age, diabetes duration, fasting blood glucose and HbA1c. RESULTS The mean age and duration of T2DM were 61.1 and 13.7 years, respectively. Although no significant differences in the average TR and ORL volumes were observed among the groups, significant differences were found in the volume and sectorial thicknesses of the inner plexiform layer (IPL), outer plexiform layer (OPL) and IRL among the groups. In particular, the thicknesses of the IPL (S3, T3, S6, I6 and T6 sectors) and the IRL (S6 sector) were decreased in the no-DR group compared with the controls (P < 0.05). The thickness of the OPL (S3, N3, S6 and N6 sectors) was thinner in the no-DR group than in mild DR (P < 0.05). The average IPL thickness was significantly negatively correlated with age and the duration of diabetes. CONCLUSION The assessment of the intra-retinal layer thickness showed a significant decrease in the IPL and IRL thicknesses in Chinese adults with T2DM, even in the absence of visible microvascular signs of DR.
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Affiliation(s)
- Shu-ting Li
- Department of Ophthalmology, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Xiang-ning Wang
- Department of Ophthalmology, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Xin-hua Du
- Department of Ophthalmology, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, China
| | - Qiang Wu
- Department of Ophthalmology, Shanghai Jiaotong University Affiliated Sixth People’s Hospital, Shanghai, China
- Shanghai Key Laboratory of Diabetes Mellitus, Shanghai, China
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Kimball EC, Pease ME, Steinhart MR, Oglesby EN, Pitha I, Nguyen C, Quigley HA. A mouse ocular explant model that enables the study of living optic nerve head events after acute and chronic intraocular pressure elevation: Focusing on retinal ganglion cell axons and mitochondria. Exp Eye Res 2017; 160:106-115. [PMID: 28414059 DOI: 10.1016/j.exer.2017.04.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 01/03/2017] [Accepted: 04/09/2017] [Indexed: 11/16/2022]
Abstract
We developed an explant model of the mouse eye and optic nerve that facilitates the study of retinal ganglion cell axons and mitochondria in the living optic nerve head (ONH) in an ex vivo environment. Two transgenic mouse strains were used, one expressing yellow fluorescent protein in selected axons and a second strain expressing cyan fluorescent protein in all mitochondria. We viewed an explanted mouse eye and optic nerve by laser scanning microscopy at and behind the ONH, the site of glaucoma injury. Explants from previously untreated mice were studied with the intraocular pressure (IOP) set artificially at normal or elevated levels for several hours. Explants were also studied from eyes that had undergone chronic IOP elevation from 14 h to 6 weeks prior to ex vivo study. Image analysis in static images and video of individual mitochondria or axonal structure determined effects of acute and chronic IOP elevation. At normal IOP, fluorescent axonal structure was stable for up to 3 h under ex vivo conditions. After chronic IOP elevation, axonal integrity index values indicated fragmentation of axon structure in the ONH. In mice with fluorescent mitochondria, the normal density decreased with distance behind the ONH by 45% (p = 0.002, t-test). Density increased with prior chronic IOP elevation to 21,300 ± 4176 mitochondria/mm2 compared to control 16,110 ± 3159 mitochondria/mm2 (p = 0.025, t-test), but did not increase significantly after 4 h, acute IOP elevation (1.5% decrease in density, p = 0.83, t-test). Mean normal mitochondrial length of 2.3 ± 1.4 μm became 13% smaller after 4 h of IOP elevation ex vivo compared to baseline (p = 0.015, t-test, N-10). Normal mitochondrial speed of movement was significantly slower in the anterograde direction (towards the brain) than retrograde, but there were more mitochondria in motion and traveling longer lengths in anterograde direction. The percent of mitochondria in motion decreased by >50% with acute IOP increase to 30 mm Hg after 60 min. A new ocular explant model implemented with eyes from transgenic mice with fluorescent cellular components provided real time measurement of the early events in experimental glaucoma and quantitative outcomes for neuroprotection therapy experiments.
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Affiliation(s)
- Elizabeth C Kimball
- From the Glaucoma Center of Excellence, Wilmer Ophthalmological Institute, Johns Hopkins University, Baltimore, MD, USA.
| | - Mary E Pease
- From the Glaucoma Center of Excellence, Wilmer Ophthalmological Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Matthew R Steinhart
- From the Glaucoma Center of Excellence, Wilmer Ophthalmological Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Ericka N Oglesby
- From the Glaucoma Center of Excellence, Wilmer Ophthalmological Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Ian Pitha
- From the Glaucoma Center of Excellence, Wilmer Ophthalmological Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Cathy Nguyen
- From the Glaucoma Center of Excellence, Wilmer Ophthalmological Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Harry A Quigley
- From the Glaucoma Center of Excellence, Wilmer Ophthalmological Institute, Johns Hopkins University, Baltimore, MD, USA
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Electrical brain stimulation induces dendritic stripping but improves survival of silent neurons after optic nerve damage. Sci Rep 2017; 7:627. [PMID: 28377608 PMCID: PMC5428431 DOI: 10.1038/s41598-017-00487-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 02/27/2017] [Indexed: 12/29/2022] Open
Abstract
Repetitive transorbital alternating current stimulation (rtACS) improves vision in patients with chronic visual impairments and an acute treatment increased survival of retinal neurons after optic nerve crush (ONC) in rodent models of visual system injury. However, despite this protection no functional recovery could be detected in rats, which was interpreted as evidence of “silent survivor” cells. We now analysed the mechanisms underlying this “silent survival” effect. Using in vivo microscopy of the retina we investigated the survival and morphology of fluorescent neurons before and after ONC in animals receiving rtACS or sham treatment. One week after the crush, more neurons survived in the rtACS-treated group compared to sham-treated controls. In vivo imaging further revealed that in the initial post-ONC period, rtACS induced dendritic pruning in surviving neurons. In contrast, dendrites in untreated retinae degenerated slowly after the axonal trauma and neurons died. The complete loss of visual evoked potentials supports the hypothesis that cell signalling is abolished in the surviving neurons. Despite this evidence of “silencing”, intracellular free calcium imaging showed that the cells were still viable. We propose that early after trauma, complete dendritic stripping following rtACS protects neurons from excitotoxic cell death by silencing them.
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Montesano G, Gervasoni A, Ferri P, Allegrini D, Migliavacca L, De Cillà S, Rossetti L. Structure-function relationship in early diabetic retinopathy: a spatial correlation analysis with OCT and microperimetry. Eye (Lond) 2017; 31:931-939. [PMID: 28257130 DOI: 10.1038/eye.2017.27] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 01/16/2017] [Indexed: 01/05/2023] Open
Abstract
PurposeTo study the correlation of the local ganglion cell layer-inner plexiform layer (GCL-IPL) thickness with corresponding retinal sensitivity as studied with microperimetry in patients with Type 2 diabetes and no signs of diabetic retinopathy.Patients and methodsWe analyzed 35 healthy subjects (68 eyes) and 26 Type 2 diabetic patients (48 eyes) with no signs of diabetic retinopathy. We tested best corrected visual acuity (BCVA), monocular and binocular constrast sensitivity (CS, Pelli - Robson chart) and retinal sensitivity with microperimetry, and acquired dense macular SD-OCT scans. We then studied the correlation between local GCL-IPL thickness and local sensitivity.ResultsMean BCVA was 1.09 (±1.03) decimals in diabetic subjects and 1.02 (±0.15) decimals in healthy subjects. Only binocular CS was significantly higher in healthy subjects (1.18±0.42 for healthy subjects, 1.62±0.63 for diabetic subjects). In both local and global analysis we observed higher GCL-IPL thickness and higher sensitivity in normal compared with diabetic subjects, but no difference reached significance (p<0.05). Using a mixed multivariate linear model, we found a significant correlation between retinal sensitivity and the correspondent GCL-IPL thickness in diabetic subjects (0.022±0.006 dB/μm, p=0.0007) but not in healthy subjects (-0.002±0.006 dB/μm, p=0.77).Conclusiondespite close similarities between the two groups, we found a significant difference in the structure-function relationship in diabetic subjects without diabetic retinopathy, suggesting that diabetes might act as an additional effect in the normal deterioration of the visual function related to the inner retina.
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Affiliation(s)
- G Montesano
- University of Milan, San Paolo Hospital, Milan, Italy
| | - A Gervasoni
- University of Milan, San Paolo Hospital, Milan, Italy
| | - P Ferri
- University of Milan, San Paolo Hospital, Milan, Italy
| | | | - L Migliavacca
- University of Milan, San Paolo Hospital, Milan, Italy
| | - S De Cillà
- Health Sciences, Università del Piemonte Orientale, Novara, Italy
| | - L Rossetti
- University of Milan, San Paolo Hospital, Milan, Italy
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49
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Smith CA, Vianna JR, Chauhan BC. Assessing retinal ganglion cell damage. Eye (Lond) 2017; 31:209-217. [PMID: 28085141 PMCID: PMC5306472 DOI: 10.1038/eye.2016.295] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 11/21/2016] [Indexed: 11/09/2022] Open
Abstract
Retinal ganglion cell (RGC) loss is the hallmark of optic neuropathies, including glaucoma, where damage to RGC axons occurs at the level of the optic nerve head. In experimental glaucoma, damage is assessed at the axon level (in the retinal nerve fibre layer and optic nerve head) or at the soma level (in the retina). In clinical glaucoma where measurements are generally limited to non-invasive techniques, structural measurements of the retinal nerve fibre layer and optic nerve head, or functional measurements with perimetry provide surrogate estimates of RGC integrity. These surrogate measurements, while clinically useful, are several levels removed from estimating actual RGC loss. Advances in imaging, labelling techniques, and transgenic medicine are making enormous strides in experimental glaucoma, providing knowledge on the pathophysiology of glaucoma, its progression and testing new therapeutic avenues. Advances are also being made in functional imaging of RGCs. Future efforts will now be directed towards translating these advances to clinical care.
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Affiliation(s)
- C A Smith
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
| | - J R Vianna
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
| | - B C Chauhan
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
- Retina and Optic Nerve Research Laboratory, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Ophthalmology and Visual Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
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50
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Morgan JE, Tribble J, Fergusson J, White N, Erchova I. The optical detection of retinal ganglion cell damage. Eye (Lond) 2017; 31:199-205. [PMID: 28060357 PMCID: PMC5306469 DOI: 10.1038/eye.2016.290] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 11/08/2016] [Indexed: 11/08/2022] Open
Abstract
We provide an overview of developments in the use optical coherence tomography (OCT) imaging for the detection of retinal ganglion cell (RGC) damage in vivo that avoid use of any exogenous ligands to label cells. The method employs high-resolution OCT using broad spectral light sources to deliver axial resolution of under 5 μm. The resolution approximates that of cellular organelles, which undergo degenerative changes that progress to apoptosis as a result of axon damage. These degenerative changes are manifest as the loss of RGC dendrites and fragmentation of the subcellular network of organelles, in particular, the mitochondria that support dendritic structure. These changes can alter the light-scattering behavior of degenerating neurons. Using OCT imaging techniques to identify these signals in cultured neurons, we have demonstrated changes in cultured cells and in retinal explants. Pilot studies in human glaucoma suggest that similar changes are detectable in the clinical setting. High-resolution OCT can be used to detect optical scatter signals that derive from the RGC/inner plexiform layer and are associated with neuronal damage. These findings suggest that OCT instruments can be used to derive quantitative measurements of RGC damage. Critically, these signals can be detected at an early stage of RGC degeneration when cells could be protected or remodeled to support visual recovery.
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Affiliation(s)
- J E Morgan
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, UK
| | - J Tribble
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, UK
| | - J Fergusson
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, UK
| | - N White
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, UK
| | - I Erchova
- School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff, UK
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