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Lo J, Mehta K, Dhillon A, Huang YK, Luo Z, Nam MH, Al Diri I, Chang KC. Therapeutic strategies for glaucoma and optic neuropathies. Mol Aspects Med 2023; 94:101219. [PMID: 37839232 PMCID: PMC10841486 DOI: 10.1016/j.mam.2023.101219] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/02/2023] [Accepted: 10/09/2023] [Indexed: 10/17/2023]
Abstract
Glaucoma is a neurodegenerative eye disease that causes permanent vision impairment. The main pathological characteristics of glaucoma are retinal ganglion cell (RGC) loss and optic nerve degeneration. Glaucoma can be caused by elevated intraocular pressure (IOP), although some cases are congenital or occur in patients with normal IOP. Current glaucoma treatments rely on medicine and surgery to lower IOP, which only delays disease progression. First-line glaucoma medicines are supported by pharmacotherapy advancements such as Rho kinase inhibitors and innovative drug delivery systems. Glaucoma surgery has shifted to safer minimally invasive (or microinvasive) glaucoma surgery, but further trials are needed to validate long-term efficacy. Further, growing evidence shows that adeno-associated virus gene transduction and stem cell-based RGC replacement therapy hold potential to treat optic nerve fiber degeneration and glaucoma. However, better understanding of the regulatory mechanisms of RGC development is needed to provide insight into RGC differentiation from stem cells and help choose target genes for viral therapy. In this review, we overview current progress in RGC development research, optic nerve fiber regeneration, and human stem cell-derived RGC differentiation and transplantation. We also provide an outlook on perspectives and challenges in the field.
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Affiliation(s)
- Jung Lo
- Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, 83301, Taiwan
| | - Kamakshi Mehta
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA
| | - Armaan Dhillon
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Yu-Kai Huang
- Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, 80708, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan
| | - Ziming Luo
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University School of Medicine, Palo Alto, CA, 94304, USA
| | - Mi-Hyun Nam
- Sue Anschutz-Rodgers Eye Center and Department of Ophthalmology, School of Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, USA.
| | - Issam Al Diri
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.
| | - Kun-Che Chang
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA; Department of Neurobiology, Center of Neuroscience, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
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Coulon SJ, Schuman JS, Du Y, Bahrani Fard MR, Ethier CR, Stamer WD. A novel glaucoma approach: Stem cell regeneration of the trabecular meshwork. Prog Retin Eye Res 2022; 90:101063. [PMID: 35398015 PMCID: PMC9464663 DOI: 10.1016/j.preteyeres.2022.101063] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 03/20/2022] [Accepted: 03/24/2022] [Indexed: 12/13/2022]
Abstract
Glaucoma is the leading cause of global irreversible blindness, necessitating research for new, more efficacious treatment options than currently exist. Trabecular meshwork (TM) cells play an important role in the maintenance and function of the aqueous outflow pathway, and studies have found that there is decreased cellularity of the TM in glaucoma. Regeneration of the TM with stem cells has been proposed as a novel therapeutic option by several reports over the last few decades. Stem cells have the capacity for self-renewal and the potential to differentiate into adult functional cells. Several types of stem cells have been investigated in ocular regenerative medicine: tissue specific stem cells, embryonic stem cells, induced pluripotent stem cells, and adult mesenchymal stem cells. These cells have been used in various glaucoma animal models and ex vivo models and have shown success in IOP homeostasis and TM cellularity restoration. They have also demonstrated stability without serious side effects for a significant period of time. Based on current knowledge of TM pathology in glaucoma and existing literature regarding stem cell regeneration of this tissue, we propose a human clinical study as the next step in understanding this potentially revolutionary treatment paradigm. The ability to protect and replace TM cells in glaucomatous eyes could change the field forever.
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Affiliation(s)
- Sara J Coulon
- Department of Ophthalmology, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, 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; Departments of Biomedical Engineering and Electrical and Computer Engineering, New York University Tandon School of Engineering, Brooklyn, NY, USA; Department of Physiology and Neuroscience, NYU Grossman School of Medicine, NYU Langone Health, New York University, New York, NY, USA.
| | - Yiqin Du
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Mohammad Reza Bahrani Fard
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University School of Medicine, Atlanta, GA, USA
| | - C Ross Ethier
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University School of Medicine, Atlanta, GA, USA
| | - W Daniel Stamer
- Departments of Ophthalmology and Biomedical Engineering, Duke University, Durham, NC, USA
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Bertens CJF, van Mechelen RJS, Berendschot TTJM, Gijs M, Wolters JEJ, Gorgels TGMF, Nuijts RMMA, Beckers HJM. Repeatability, reproducibility, and agreement of three tonometers for measuring intraocular pressure in rabbits. Sci Rep 2021; 11:19217. [PMID: 34584185 PMCID: PMC8478901 DOI: 10.1038/s41598-021-98762-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 09/14/2021] [Indexed: 12/04/2022] Open
Abstract
The aim of this study was to evaluate repeatability, reproducibility, and agreement of three commonly used tonometers in animal research (TonoLab, TonoVet, and TonoPEN AVIA) in a cohort of 24 rabbits. Additionally, the impact of sedation on IOP was investigated in 21 New Zealand White rabbits with the TonoVet tonometer. Repeatability was determined using the coefficient of variation (CoV) for two observers. For the TonoLab (6.55%) and TonoVet (6.38%) the CoV was lower than for the TonoPEN AVIA (10.88%). The reproducibility was highest for the TonoVet (0.2 ± 3.3 mmHg), followed by the TonoLab (0 ± 12.89 mmHg) and lowest for the TonoPEN AVIA (− 1.48 ± 10.3 mmHg). The TonoLab and TonoVet showed the highest agreement (r = 0.85, R2 = 0.73). After sedation, a significant IOP reduction (often > 25%) was observed. Our results show that among the three tonometers tested, the TonoVet tonometer is best for use in rabbits while the TonoLab should be avoided. The impact of sedation on IOP was substantial and should be taken into account during experimentation.
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Affiliation(s)
- Christian J F Bertens
- Department of Ophthalmology, University Eye Clinic Maastricht, School for Mental Health and Neuroscience (MHeNs), Maastricht University Medical Center+ (MUMC+), P. Debyelaan 25, PO Box 5800, 6229 HX, Maastricht, The Netherlands. .,Chemelot Institute for Science and Technology (InSciTe), Gaetano Martinolaan 63-65, 6229 GS, Maastricht, The Netherlands.
| | - Ralph J S van Mechelen
- Department of Ophthalmology, University Eye Clinic Maastricht, School for Mental Health and Neuroscience (MHeNs), Maastricht University Medical Center+ (MUMC+), P. Debyelaan 25, PO Box 5800, 6229 HX, Maastricht, The Netherlands.,Chemelot Institute for Science and Technology (InSciTe), Gaetano Martinolaan 63-65, 6229 GS, Maastricht, The Netherlands
| | - Tos T J M Berendschot
- Department of Ophthalmology, University Eye Clinic Maastricht, School for Mental Health and Neuroscience (MHeNs), Maastricht University Medical Center+ (MUMC+), P. Debyelaan 25, PO Box 5800, 6229 HX, Maastricht, The Netherlands
| | - Marlies Gijs
- Department of Ophthalmology, University Eye Clinic Maastricht, School for Mental Health and Neuroscience (MHeNs), Maastricht University Medical Center+ (MUMC+), P. Debyelaan 25, PO Box 5800, 6229 HX, Maastricht, The Netherlands.,Chemelot Institute for Science and Technology (InSciTe), Gaetano Martinolaan 63-65, 6229 GS, Maastricht, The Netherlands
| | - Jarno E J Wolters
- Department of Ophthalmology, University Eye Clinic Maastricht, School for Mental Health and Neuroscience (MHeNs), Maastricht University Medical Center+ (MUMC+), P. Debyelaan 25, PO Box 5800, 6229 HX, Maastricht, The Netherlands.,Chemelot Institute for Science and Technology (InSciTe), Gaetano Martinolaan 63-65, 6229 GS, Maastricht, The Netherlands
| | - Theo G M F Gorgels
- Department of Ophthalmology, University Eye Clinic Maastricht, School for Mental Health and Neuroscience (MHeNs), Maastricht University Medical Center+ (MUMC+), P. Debyelaan 25, PO Box 5800, 6229 HX, Maastricht, The Netherlands.,Chemelot Institute for Science and Technology (InSciTe), Gaetano Martinolaan 63-65, 6229 GS, Maastricht, The Netherlands
| | - Rudy M M A Nuijts
- Department of Ophthalmology, University Eye Clinic Maastricht, School for Mental Health and Neuroscience (MHeNs), Maastricht University Medical Center+ (MUMC+), P. Debyelaan 25, PO Box 5800, 6229 HX, Maastricht, The Netherlands.,Chemelot Institute for Science and Technology (InSciTe), Gaetano Martinolaan 63-65, 6229 GS, Maastricht, The Netherlands
| | - Henny J M Beckers
- Department of Ophthalmology, University Eye Clinic Maastricht, School for Mental Health and Neuroscience (MHeNs), Maastricht University Medical Center+ (MUMC+), P. Debyelaan 25, PO Box 5800, 6229 HX, Maastricht, The Netherlands.,Chemelot Institute for Science and Technology (InSciTe), Gaetano Martinolaan 63-65, 6229 GS, Maastricht, The Netherlands
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Fazio MA, Girard MJA, Lee W, Morris JS, Burgoyne CF, Downs JC. The Relationship Between Scleral Strain Change and Differential Cumulative Intraocular Pressure Exposure in the Nonhuman Primate Chronic Ocular Hypertension Model. Invest Ophthalmol Vis Sci 2019; 60:4141-4150. [PMID: 31598625 PMCID: PMC6785842 DOI: 10.1167/iovs.19-27060] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 08/17/2019] [Indexed: 01/15/2023] Open
Abstract
Purpose To determine the relationship between peripapillary scleral strain change and cumulative differential IOP exposure in nonhuman primates (NHPs) with unilateral chronic ocular hypertension. Methods Posterior scleral shells from 6 bilaterally normal and 10 unilateral chronic ocular hypertension NHPs were pressurized from 5 to 45 mm Hg, and the resulting full-field, three-dimensional, scleral surface deformations were acquired using laser speckle interferometry. Scleral tensile strain (local tissue deformation) was calculated by analytical differentiation of the displacement field; zero strain was assumed at 5 mm Hg. Maximum principal strain was used to represent the scleral strain, and strains were averaged over a 15°-wide (∼3.6-mm) circumpapillary region adjacent to the ONH. The relative difference in mean strain was calculated between fellow eyes and compared with the differential cumulative IOP exposure within NHPs during the study period. The relationship between the relative difference in scleral strain and the differential cumulative IOP exposure in fellow eyes was assessed using an F test and quadratic regression model. Results Relative differential scleral tensile strain was significantly associated with differential cumulative IOP exposure in contralateral eyes in the chronic ocular hypertension NHPs, with the bilaterally normal NHPs showing no significant strain difference between fellow eyes. The sclera in the chronic ocular hypertension eyes was more compliant than in their fellow eyes at low levels of differential cumulative IOP exposure, but stiffer at larger differential IOPs (P < 0.0001). Conclusions These cross-sectional findings suggest that longitudinal IOP-induced changes in scleral mechanical behavior are dependent on the magnitude of differential cumulative IOP exposure.
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Affiliation(s)
- Massimo A. Fazio
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Michael J. A. Girard
- In Vivo Biomechanics Laboratory, Department of Biomedical Engineering, National University of Singapore, Singapore
| | - Wonyul Lee
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States
| | - Jeffrey S. Morris
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States
| | - Claude F. Burgoyne
- Optic Nerve Head Biomechanics Laboratory, Devers Eye Institute, Portland, Oregon, United States
| | - J. Crawford Downs
- Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama, United States
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5
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Tu S, Li K, Hu D, Li K, Ge J. Posture-Dependent 24-Hour Intraocular Pressure Fluctuation Patterns in an Intraocular Hypertension Monkey Model. Transl Vis Sci Technol 2019; 8:63. [PMID: 31293817 PMCID: PMC6602140 DOI: 10.1167/tvst.8.3.63] [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: 09/17/2018] [Accepted: 03/04/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose We investigate 24-hour intraocular pressure (IOP) fluctuation patterns and the influence of body position on IOP in a chronic ocular hypertension (COHT) monkey model. Methods We recorded 24-hour IOPs (nine time points) in the different body positions in 10 eyes with normal and eight with high IOP (with random selection of one eye of each monkey) using a Tonopen. The IOPs at various time points and in different body positions were compared. Results The average 24-hour IOPs in the immediate-supine, 10-minute supine, 10-minute seated, and immediate-seated positions in the COHT models were 28.64 ± 9.82, 25.42 ± 7.62, 23.49 ± 7.67, and 20.53 ± 7.80 mmHg, respectively. The diurnal-to-nocturnal IOP changes were 8.51 ± 2.93, 5.81 ± 3.67, 5.48 ± 2.97, and 3.59 ± 2.74 mmHg, respectively. The sudden shift between the supine and seated positions bring greater IOP variations (8.11 ± 2.85 mmHg) in the COHT monkeys, and the IOP fluctuations reached 14 to 38 mmHg when considering body position and the measurement time points. Conclusions The measurement time and body position influenced IOP. More elevated IOP occurred in the immediate-supine position and during the transient shift between the seated and supine positions. Maintaining a fixed position for sufficient time before measurement is important. Translational Relevance Glaucoma patients should focus on the importance of IOP measurements in the clinic occurring after an adequate amount of time in a fixed body position.
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Affiliation(s)
- Shu Tu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kang Li
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Dongpeng Hu
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Kaijing Li
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jian Ge
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Evangelho K, Mastronardi CA, de-la-Torre A. Experimental Models of Glaucoma: A Powerful Translational Tool for the Future Development of New Therapies for Glaucoma in Humans-A Review of the Literature. MEDICINA (KAUNAS, LITHUANIA) 2019; 55:E280. [PMID: 31212881 PMCID: PMC6630440 DOI: 10.3390/medicina55060280] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 06/04/2019] [Accepted: 06/04/2019] [Indexed: 12/18/2022]
Abstract
Glaucoma is a common complex disease that leads to irreversible blindness worldwide. Even though preclinical studies showed that lowering intraocular pressure (IOP) could prevent retinal ganglion cells loss, clinical evidence suggests that lessening IOP does not prevent glaucoma progression in all patients. Glaucoma is also becoming more prevalent in the elderly population, showing that age is a recognized major risk factor. Indeed, recent findings suggest that age-related tissue alterations contribute to the development of glaucoma and have encouraged exploration for new treatment approaches. In this review, we provide information on the most frequently used experimental models of glaucoma and describe their advantages and limitations. Additionally, we describe diverse animal models of glaucoma that can be potentially used in translational medicine and aid an efficient shift to the clinic. Experimental animal models have helped to understand the mechanisms of formation and evacuation of aqueous humor, and the maintenance of homeostasis of intra-ocular pressure. However, the transfer of pre-clinical results obtained from animal studies into clinical trials may be difficult since the type of study does not only depend on the type of therapy to be performed, but also on a series of factors observed both in the experimental period and the period of transfer to clinical application. Conclusions: Knowing the exact characteristics of each glaucoma experimental model could help to diminish inconveniences related to the process of the translation of results into clinical application in humans.
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Affiliation(s)
- Karine Evangelho
- Doctorado en Ciencias Biomédicas y Biológicas, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá,11121, Colombia.
| | - Claudio A Mastronardi
- Neuroscience Research Group (NeurUROS), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, 11121, Colombia.
| | - Alejandra de-la-Torre
- Neuroscience Research Group (NeurUROS), Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, 11121, Colombia.
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Morrison JC, Cepurna WO, Tehrani S, Choe TE, Jayaram H, Lozano DC, Fortune B, Johnson EC. A Period of Controlled Elevation of IOP (CEI) Produces the Specific Gene Expression Responses and Focal Injury Pattern of Experimental Rat Glaucoma. Invest Ophthalmol Vis Sci 2017; 57:6700-6711. [PMID: 27942722 PMCID: PMC5156512 DOI: 10.1167/iovs.16-20573] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose We determine if several hours of controlled elevation of IOP (CEI) will produce the optic nerve head (ONH) gene expression changes and optic nerve (ON) damage pattern associated with early experimental glaucoma in rats. Methods The anterior chambers of anesthetized rats were cannulated and connected to a reservoir to elevate IOP. Physiologic parameters were monitored. Following CEI at various recovery times, ON cross-sections were graded for axonal injury. Anterior ONHs were collected at 0 hours to 10 days following CEI and RNA extracted for quantitative PCR measurement of selected messages. The functional impact of CEI was assessed by electroretinography (ERG). Results During CEI, mean arterial pressure (99 ± 6 mm Hg) and other physiologic parameters remained stable. An 8-hour CEI at 60 mm Hg produced significant focal axonal degeneration 10 days after exposure, with superior lesions in 83% of ON. Message analysis in CEI ONH demonstrated expression responses previously identified in minimally injured ONH following chronic IOP elevation, as well as their sequential patterns. Anesthesia with cannulation at 20 mm Hg did not alter these message levels. Electroretinographic A- and B-waves, following a significant reduction at 2 days after CEI, were fully recovered at 2 weeks, while peak scotopic threshold response (pSTR) remained mildly but significantly depressed. Conclusions A single CEI reproduces ONH message changes and patterns of ON injury previously observed with chronic IOP elevation. Controlled elevation of IOP can allow detailed determination of ONH cellular and functional responses to an injurious IOP insult and provide a platform for developing future therapeutic interventions.
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Affiliation(s)
- John C Morrison
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - William O Cepurna
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Shandiz Tehrani
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Tiffany E Choe
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Hari Jayaram
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States 2Glaucoma Service, NIHR Moorfields Biomedical Research Centre, London, United Kingdom
| | - Diana C Lozano
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Brad Fortune
- Devers Eye Institute, Portland, Oregon, United States
| | - Elaine C Johnson
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
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8
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Sanchez RF, Vieira da Silva MJ, Dawson C. Design of an intraocular pressure curve protocol for use in dogs. J Small Anim Pract 2016; 58:42-48. [DOI: 10.1111/jsap.12600] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 07/25/2016] [Accepted: 09/25/2016] [Indexed: 11/29/2022]
Affiliation(s)
- R. F. Sanchez
- Queen Mother Hospital for Animals, Royal Veterinary College; University of London; Hertfordshire AL9 7TA
| | | | - C. Dawson
- Queen Mother Hospital for Animals, Royal Veterinary College; University of London; Hertfordshire AL9 7TA
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Zouache MA, Eames I, Samsudin A. Allometry and Scaling of the Intraocular Pressure and Aqueous Humour Flow Rate in Vertebrate Eyes. PLoS One 2016; 11:e0151490. [PMID: 26990431 PMCID: PMC4798774 DOI: 10.1371/journal.pone.0151490] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 02/29/2016] [Indexed: 11/23/2022] Open
Abstract
In vertebrates, intraocular pressure (IOP) is required to maintain the eye into a shape allowing it to function as an optical instrument. It is sustained by the balance between the production of aqueous humour by the ciliary body and the resistance to its outflow from the eye. Dysregulation of the IOP is often pathological to vision. High IOP may lead to glaucoma, which is in man the second most prevalent cause of blindness. Here, we examine the importance of the IOP and rate of formation of aqueous humour in the development of vertebrate eyes by performing allometric and scaling analyses of the forces acting on the eye during head movement and the energy demands of the cornea, and testing the predictions of the models against a list of measurements in vertebrates collated through a systematic review. We show that the IOP has a weak dependence on body mass, and that in order to maintain the focal length of the eye, it needs to be an order of magnitude greater than the pressure drop across the eye resulting from gravity or head movement. This constitutes an evolutionary constraint that is common to all vertebrates. In animals with cornea-based optics, this constraint also represents a condition to maintain visual acuity. Estimated IOPs were found to increase with the evolution of terrestrial animals. The rate of formation of aqueous humour was found to be adjusted to the metabolic requirements of the cornea, scaling as Vac(0.67), where Vac is the volume of the anterior chamber. The present work highlights an interdependence between IOP and aqueous flow rate crucial to ocular function that must be considered to understand the evolution of the dioptric apparatus. It should also be taken into consideration in the prevention and treatment of glaucoma.
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Affiliation(s)
- Moussa A. Zouache
- Institute of Ophthalmology, University College London, London, United Kingdom
| | - Ian Eames
- Department of Mechanical Engineering, University College London, London, United Kingdom
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Liu K, Wang N, Peng X, Yang D, Wang C, Zeng H. Long-term effect of laser-induced ocular hypertension on the cone electroretinogram and central macular thickness in monkeys. Photomed Laser Surg 2016; 32:371-8. [PMID: 24992271 DOI: 10.1089/pho.2013.3693] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE The purpose of this study was to investigate the long-term effect of laser-induced ocular hypertension on the cone electroretinogram (ERG) and retinal thickness in monkeys. BACKGROUND DATA Degeneration of retinal nerve fiber layer (RNFL) and loss of retinal ganglion cells in the primate glaucoma model have been confirmed by histological studies and optical coherence tomography (OCT) images. However, it remains unclear whether the outer retina distal to the RGCs (e.g., photoreceptors) is involved in histological studies and in functional test. MATERIALS AND METHODS Subjects were five monkeys with high intraocular pressure (IOP) induced in the right eye by laser. Six years after the laser coagulation of the mid-trabecular meshwork, RNFL, ganglion cell complex (GCC), central macular thickness (CMT), and the thickness of outer retinal layer (ORL) were measured by OCT. The photopic responses of ERG were recorded in response to red flashes on a blue background. The maximum cone amplitude (Rcone) and cone sensitivity (Scone) were calculated. RESULTS Enlarged cup-to-disc (C/D) ratio was found in the lasered eyes. RNFL and GCC were significantly thinner in the lasered eyes (p<0.05), but no significant differences were found in CMT and the thickness of ORL compared with fellow eyes (p>0.05). Mean amplitude of the photopic negative response (PhNR), Mean Rcone were significantly lower in the lasered eye (p<0.05), and no significant differences of Scone were found between the two eyes (p>0.05). CONCLUSIONS Long-term ocular hypertension induced by laser affects the function of cone photoreceptor in monkeys.
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Affiliation(s)
- Kegao Liu
- 1 Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University , Beijing, China
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Raposo A, Ofri R, Schaffer D, Gomes Júnior D, Libório F, Martins Filho E, Oriá A. Evaluation of ophthalmic and hemodynamic parameters in capuchin monkeys (Sapajus
sp.) submitted to dissociative anesthetic protocols. J Med Primatol 2015; 44:381-9. [DOI: 10.1111/jmp.12200] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2015] [Indexed: 11/30/2022]
Affiliation(s)
- A.C.S. Raposo
- School of Veterinary Medicine and Zootechny; Federal University of Bahia UFBA; Salvador BA Brazil
| | - R. Ofri
- The Koret School of Veterinary Medicine; The Hebrew University of Jerusalem; Jerusalem Israel
| | - D.P.H. Schaffer
- School of Veterinary Medicine and Zootechny; Federal University of Bahia UFBA; Salvador BA Brazil
| | - D.C. Gomes Júnior
- School of Veterinary Medicine and Zootechny; Federal University of Bahia UFBA; Salvador BA Brazil
| | - F.A. Libório
- Screening Center for Wild Animals (CETAS); Salvador BA Brazil
| | - E.F. Martins Filho
- Faculdade de Ciências Agrárias e Veterinárias; UNESP; São Paulo State University; Jaboticabal SP Brazil
| | - A.P. Oriá
- School of Veterinary Medicine and Zootechny; Federal University of Bahia UFBA; Salvador BA Brazil
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Morrison JC, Cepurna WO, Johnson EC. Modeling glaucoma in rats by sclerosing aqueous outflow pathways to elevate intraocular pressure. Exp Eye Res 2015; 141:23-32. [PMID: 26003399 DOI: 10.1016/j.exer.2015.05.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 05/18/2015] [Accepted: 05/19/2015] [Indexed: 12/14/2022]
Abstract
Injection of hypertonic saline via episcleral veins toward the limbus in laboratory rats can produce elevated intraocular pressure (IOP) by sclerosis of aqueous humor outflow pathways. This article describes important anatomic characteristics of the rat optic nerve head (ONH) that make it an attractive animal model for human glaucoma, along with the anatomy of rat aqueous humor outflow on which this technique is based. The injection technique itself is also described, with the aid of a supplemental movie, including necessary equipment and specific tips to acquire this skill. Outcomes of a successful injection are presented, including IOP elevation and patterns of optic nerve injury. These concepts are then specifically considered in light of the use of this model to assess potential neuroprotective therapies. Advantages of the hypertonic saline model include a delayed and relatively gradual IOP elevation, likely reproduction of scleral and ONH stresses and strains that may be important in producing axonal injury, and its ability to be applied to any rat (and potentially mouse) strain, leaving the unmanipulated fellow eye as an internal control. Challenges include the demanding surgical skill required by the technique itself, a wide range of IOP response, and mild corneal clouding in some animals. However, meticulous application of the principles detailed in this article and practice will allow most researchers to attain this useful skill for studying cellular events of glaucomatous optic nerve damage.
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Affiliation(s)
- John C Morrison
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, USA.
| | - William O Cepurna
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, USA
| | - Elaine C Johnson
- The Kenneth C. Swan Ocular Neurobiology Laboratory, Casey Eye Institute, Oregon Health and Science University, USA
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Analysis of a method for establishing a model with more stable chronic glaucoma in rhesus monkeys. Exp Eye Res 2015; 131:56-62. [DOI: 10.1016/j.exer.2014.12.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 11/03/2014] [Accepted: 12/19/2014] [Indexed: 11/30/2022]
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KIM J, SAPP HLJ, PLUMMER CE, BROOKS DE, KIM D, KIM MS. IOP Change Undergoing Anesthesia in Rhesus Macaques ( Macaca mulatta) with Laser-Induced Ocular Hypertension. J Vet Med Sci 2012; 74:1359-61. [DOI: 10.1292/jvms.12-0059] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Jury KIM
- College of Veterinary Medicine, Chonbuk National University, 664–14 Duckjin-dong, Duckjin-ku, Jeonju 561–756, Korea
| | - Harold L. Jr. SAPP
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32618, U.S.A
| | - Caryn E. PLUMMER
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32618, U.S.A
| | - Dennis E. BROOKS
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida 32618, U.S.A
| | - Daeyoung KIM
- Department of Life Sciences, College of Bionano Technology, Gachon University, 534–2 Yeonsu-dong, Yeonsu-gu, Incheon, 406–799, Korea
| | - Min-Su KIM
- College of Veterinary Medicine, Chonbuk National University, 664–14 Duckjin-dong, Duckjin-ku, Jeonju 561–756, Korea
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Girard MJA, Suh JKF, Bottlang M, Burgoyne CF, Downs JC. Biomechanical changes in the sclera of monkey eyes exposed to chronic IOP elevations. Invest Ophthalmol Vis Sci 2011; 52:5656-69. [PMID: 21519033 PMCID: PMC3176060 DOI: 10.1167/iovs.10-6927] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Revised: 02/18/2011] [Accepted: 03/31/2011] [Indexed: 10/18/2022] Open
Abstract
PURPOSE To characterize scleral biomechanics in both eyes of eight monkeys in which chronic intraocular pressure (IOP) elevation was induced in one eye. METHODS Each posterior sclera was mounted on a pressurization apparatus, IOP was elevated from 5 to 45 mm Hg while the 3D displacements of the scleral surface were measured by speckle interferometry. Finite element (FE) models of each scleral shell were constructed that incorporated stretch-induced stiffening and multidirectionality of the collagen fibers. FE model predictions were then iteratively matched to experimental displacements to extract unique sets of scleral biomechanical properties. RESULTS For all eyes, the posterior sclera exhibited inhomogeneous, anisotropic, nonlinear biomechanical behavior. Biomechanical changes caused by chronic IOP elevation were complex and specific to each subject. Specifically: (1) Glaucomatous eyes in which the contralateral normal eyes displayed large modulus or thickness were less prone to biomechanical changes; (2) glaucomatous scleral modulus associated with an IOP of 10 mm Hg decreased (when compared with that of the contralateral normal) after minimal chronic IOP elevation; (3) glaucomatous scleral modulus associated with IOPs of 30 and 45 mm Hg increased (when compared with that of the contralateral normal) after moderate IOP elevation; and (4) FE-based estimates of collagen fiber orientation demonstrated no change in the glaucomatous eyes. CONCLUSIONS Significant stiffening of the sclera follows exposure to moderate IOP elevations in most eyes. Scleral hypercompliance may precede stiffening or be a unique response to minimal chronic IOP elevation in some eyes. These biomechanical changes are likely to be the result of scleral extracellular matrix remodeling.
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Affiliation(s)
- Michaël J. A. Girard
- From the Ocular Biomechanics Laboratory and
- the Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana; and
| | - J.-K. Francis Suh
- the Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana; and
| | - Michael Bottlang
- the Biomechanics Laboratory, Legacy Research and Technology Center, Portland, Oregon
| | - Claude F. Burgoyne
- the Optic Nerve Head Research Laboratory, Devers Eye Institute, Portland, Oregon
- the Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana; and
| | - J. Crawford Downs
- From the Ocular Biomechanics Laboratory and
- the Department of Biomedical Engineering, Tulane University, New Orleans, Louisiana; and
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Abstract
The monkey model of ocular hypertension (OHT) with its resultant optic neuropathy closely reflects the optic neurodegeneration associated with human glaucoma. Utilization of the experimental glaucoma model (ExpG) in non-human primates (NHP) has led to advances in the understanding of aqueous humor dynamics, glaucomatous changes in the visual pathways from photoreceptors to the visual cortex, and anterior and posterior ocular segment pharmacological effects.
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Affiliation(s)
- Carol A Rasmussen
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin 53792-3220, USA
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