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Tse T, Chen Y, Siadati M, Miao Y, Song J, Ma D, Mammo Z, Ju MJ. Generalized 3D registration algorithm for enhancing retinal optical coherence tomography images. J Biomed Opt 2024; 29:066002. [PMID: 38745984 PMCID: PMC11091473 DOI: 10.1117/1.jbo.29.6.066002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/25/2024] [Accepted: 05/01/2024] [Indexed: 05/16/2024]
Abstract
Significance Optical coherence tomography (OCT) has emerged as the standard of care for diagnosing and monitoring the treatment of various ocular disorders due to its noninvasive nature and in vivo volumetric acquisition capability. Despite its widespread applications in ophthalmology, motion artifacts remain a challenge in OCT imaging, adversely impacting image quality. While several multivolume registration algorithms have been developed to address this issue, they are often designed to cater to one specific OCT system or acquisition protocol. Aim We aim to generate an OCT volume free of motion artifacts using a system-agnostic registration algorithm that is independent of system specifications or protocol. Approach We developed a B-scan registration algorithm that removes motion and corrects for both translational eye movements and rotational angle differences between volumes. Tests were carried out on various datasets obtained from two different types of custom-built OCT systems and one commercially available system to determine the reliability of the proposed algorithm. Additionally, different system specifications were used, with variations in axial resolution, lateral resolution, signal-to-noise ratio, and real-time motion tracking. The accuracy of this method has further been evaluated through mean squared error (MSE) and multiscale structural similarity index measure (MS-SSIM). Results The results demonstrate improvements in the overall contrast of the images, facilitating detailed visualization of retinal vasculatures in both superficial and deep vasculature plexus. Finer features of the inner and outer retina, such as photoreceptors and other pathology-specific features, are discernible after multivolume registration and averaging. Quantitative analyses affirm that increasing the number of averaged registered volumes will decrease MSE and increase MS-SSIM as compared to the reference volume. Conclusions The multivolume registered data obtained from this algorithm offers significantly improved visualization of the retinal microvascular network as well as retinal morphological features. Furthermore, we have validated that the versatility of our methodology extends beyond specific OCT modalities, thereby enhancing the clinical utility of OCT for the diagnosis and monitoring of ocular pathologies.
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Affiliation(s)
- Tiffany Tse
- The University of British Columbia, School of Biomedical Engineering, Faculty of Medicine and Applied Science, Vancouver, British Columbia, Canada
| | - Yudan Chen
- The University of British Columbia, School of Biomedical Engineering, Faculty of Medicine and Applied Science, Vancouver, British Columbia, Canada
| | - Mahsa Siadati
- The University of British Columbia, School of Biomedical Engineering, Faculty of Medicine and Applied Science, Vancouver, British Columbia, Canada
| | - Yusi Miao
- The University of British Columbia, Department of Ophthalmology and Visual Sciences, Faculty of Medicine, Vancouver, British Columbia, Canada
| | - Jun Song
- The University of British Columbia, School of Biomedical Engineering, Faculty of Medicine and Applied Science, Vancouver, British Columbia, Canada
| | - Da Ma
- Wake Forest University, School of Medicine, Winston-Salem, North Carolina, United States
| | - Zaid Mammo
- The University of British Columbia, Department of Ophthalmology and Visual Sciences, Faculty of Medicine, Vancouver, British Columbia, Canada
| | - Myeong Jin Ju
- The University of British Columbia, School of Biomedical Engineering, Faculty of Medicine and Applied Science, Vancouver, British Columbia, Canada
- The University of British Columbia, Department of Ophthalmology and Visual Sciences, Faculty of Medicine, Vancouver, British Columbia, Canada
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2
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Obasanmi G, Uppal M, Cui JZ, Xi J, Ju MJ, Song J, To E, Li S, Khan W, Cheng D, Zhu J, Irani L, Samad I, Zhu J, Yoo HS, Aubert A, Stoddard J, Neuringer M, Granville DJ, Matsubara JA. Correction: Granzyme B degrades extracellular matrix and promotes inflammation and choroidal neovascularization. Angiogenesis 2024:10.1007/s10456-024-09919-7. [PMID: 38700585 DOI: 10.1007/s10456-024-09919-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Affiliation(s)
- Gideon Obasanmi
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Manjosh Uppal
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Jing Z Cui
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Jeanne Xi
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Myeong Jin Ju
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
- School of Biomedical Engineering, UBC, Vancouver, BC, Canada
| | - Jun Song
- School of Biomedical Engineering, UBC, Vancouver, BC, Canada
| | - Eleanor To
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Siqi Li
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Wania Khan
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Darian Cheng
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - John Zhu
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Lyden Irani
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Isa Samad
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Julie Zhu
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Hyung-Suk Yoo
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Alexandre Aubert
- International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute, University of British Columbia (UBC), Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, UBC, Vancouver, BC, Canada
| | | | | | - David J Granville
- International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute, University of British Columbia (UBC), Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, UBC, Vancouver, BC, Canada
| | - Joanne A Matsubara
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada.
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3
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Obasanmi G, Uppal M, Cui JZ, Xi J, Ju MJ, Song J, To E, Li S, Khan W, Cheng D, Zhu J, Irani L, Samad I, Zhu J, Yoo HS, Aubert A, Stoddard J, Neuringer M, Granville DJ, Matsubara JA. Granzyme B degrades extracellular matrix and promotes inflammation and choroidal neovascularization. Angiogenesis 2024:10.1007/s10456-024-09909-9. [PMID: 38498232 DOI: 10.1007/s10456-024-09909-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/11/2024] [Indexed: 03/20/2024]
Abstract
Age-related macular degeneration (AMD) is a common retinal neurodegenerative disease among the elderly. Neovascular AMD (nAMD), a leading cause of AMD-related blindness, involves choroidal neovascularization (CNV), which can be suppressed by anti-angiogenic treatments. However, current CNV treatments do not work in all nAMD patients. Here we investigate a novel target for AMD. Granzyme B (GzmB) is a serine protease that promotes aging, chronic inflammation and vascular permeability through the degradation of the extracellular matrix (ECM) and tight junctions. Extracellular GzmB is increased in retina pigment epithelium (RPE) and mast cells in the choroid of the healthy aging outer retina. It is further increased in donor eyes exhibiting features of nAMD and CNV. Here, we show in RPE-choroidal explant cultures that exogenous GzmB degrades the RPE-choroid ECM, promotes retinal/choroidal inflammation and angiogenesis while diminishing anti-angiogenic factor, thrombospondin-1 (TSP-1). The pharmacological inhibition of either GzmB or mast-cell degranulation significantly reduces choroidal angiogenesis. In line with our in vitro data, GzmB-deficiency reduces the extent of laser-induced CNV lesions and the age-related deterioration of electroretinogram (ERG) responses in mice. These findings suggest that targeting GzmB, a serine protease with no known endogenous inhibitors, may be a potential novel therapeutic approach to suppress CNV in nAMD.
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Affiliation(s)
- Gideon Obasanmi
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Manjosh Uppal
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Jing Z Cui
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Jeanne Xi
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Myeong Jin Ju
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
- School of Biomedical Engineering, UBC, Vancouver, BC, Canada
| | - Jun Song
- School of Biomedical Engineering, UBC, Vancouver, BC, Canada
| | - Eleanor To
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Siqi Li
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Wania Khan
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Darian Cheng
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - John Zhu
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Lyden Irani
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Isa Samad
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Julie Zhu
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Hyung-Suk Yoo
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada
| | - Alexandre Aubert
- International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute, University of British Columbia (UBC), Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, UBC, Vancouver, BC, Canada
| | | | | | - David J Granville
- International Collaboration On Repair Discoveries (ICORD), Vancouver Coastal Health Research Institute, University of British Columbia (UBC), Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, UBC, Vancouver, BC, Canada
| | - Joanne A Matsubara
- Department of Ophthalmology and Visual Sciences, UBC, Vancouver, BC, Canada.
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Stephenson KAJ, Miao Y, Ju MJ, Mammo ZN. Multimodal imaging and PD-OCT analysis of an isolated focal scleral nodule in a young female. Can J Ophthalmol 2024; 59:e88-e89. [PMID: 37778396 DOI: 10.1016/j.jcjo.2023.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 07/22/2023] [Accepted: 09/01/2023] [Indexed: 10/03/2023]
Affiliation(s)
- Kirk A J Stephenson
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, BC.
| | - Yusi Miao
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, BC
| | - Myeong Jin Ju
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, BC
| | - Zaid N Mammo
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, BC
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Miao Y, Jung H, Hsu D, Song J, Ni S, Ma D, Jian Y, Makita S, Yasuno Y, Sarunic MV, Stephenson KAJ, Paton K, Mammo Z, Ju MJ. Polarization-Diversity Optical Coherence Tomography Assessment of Choroidal Nevi. Invest Ophthalmol Vis Sci 2023; 64:6. [PMID: 37930688 PMCID: PMC10629548 DOI: 10.1167/iovs.64.14.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 10/09/2023] [Indexed: 11/07/2023] Open
Abstract
Purpose The purpose of this study was to demonstrate the utility of polarization-diversity optical coherence tomography (PD-OCT), a noninvasive imaging technique with melanin-specific contrast, in the quantitative and qualitative assessment of choroidal nevi. Methods Nevi were imaged with a custom-built 55-degree field-of-view (FOV) 400 kHz PD-OCT system. Imaging features on PD-OCT were compared to those on fundus photography, auto-fluorescence, ultrasound, and non-PD-OCT images. Lesions were manually segmented for size measurement and metrics for objective assessment of melanin distributions were calculated, including degree of polarization uniformity (DOPU), attenuation coefficient, and melanin occupancy rate (MOR). Results We imaged 17 patients (mean age = 69.5 years, range = 37-90) with 11 pigmented, 3 non-pigmented, and 3 mixed pigmentation nevi. Nevi with full margin acquisition had an average longest basal diameter of 5.1 mm (range = 2.99-8.72 mm) and average height of 0.72 mm (range = 0.37 mm-2.09 mm). PD-OCT provided clear contrast of choroidal melanin content, distribution, and delineation of nevus margins for melanotic nevi. Pigmented nevi were found to have lower DOPU, higher attenuation coefficient, and higher MOR than non-pigmented lesions. Melanin content on PD-OCT was consistent with pigmentation on fundus in 15 of 17 nevi (88%). Conclusions PD-OCT allows objective assessment of choroidal nevi melanin content and distribution. In addition, melanin-specific contrast by PD-OCT enables clear nevus margin delineation and may improve serial growth surveillance. Further investigation is needed to determine the clinical significance and prognostic value of melanin characterization by PD-OCT in the evaluation of choroidal nevi.
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Affiliation(s)
- Yusi Miao
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hoyoung Jung
- Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Destiny Hsu
- School of Engineering Science, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Jun Song
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shuibin Ni
- Case Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Da Ma
- Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, United States
| | - Yifan Jian
- Case Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Shuichi Makita
- Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yoshiaki Yasuno
- Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Marinko V. Sarunic
- School of Engineering Science, Simon Fraser University, Burnaby, British Columbia, Canada
- Department of Medical Physics and Biomedical Engineering, University College London, London, England, United Kingdom
- Institute of Ophthalmology, University College London, London, England, United Kingdom
| | - Kirk A. J. Stephenson
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Katherine Paton
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zaid Mammo
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Myeong Jin Ju
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
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7
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Chen S, Ma D, Lee S, Yu TTL, Xu G, Lu D, Popuri K, Ju MJ, Sarunic MV, Beg MF. Segmentation-guided domain adaptation and data harmonization of multi-device retinal optical coherence tomography using cycle-consistent generative adversarial networks. Comput Biol Med 2023; 159:106595. [PMID: 37087780 DOI: 10.1016/j.compbiomed.2023.106595] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/26/2022] [Accepted: 01/22/2023] [Indexed: 03/06/2023]
Abstract
BACKGROUND Medical images such as Optical Coherence Tomography (OCT) images acquired from different devices may show significantly different intensity profiles. An automatic segmentation model trained on images from one device may perform poorly when applied to images acquired using another device, resulting in a lack of generalizability. This study addresses this issue using domain adaptation methods improved by Cycle-Consistent Generative Adversarial Networks (CycleGAN), especially when the ground-truth labels are only available in the source domain. METHODS A two-stage pipeline is proposed to generate segmentation in the target domain. The first stage involves the training of a state-of-the-art segmentation model in the source domain. The second stage aims to adapt the images from the target domain to the source domain. The adapted target domain images are segmented using the model in the first stage. Ablation tests were performed with integration of different loss functions, and the statistical significance of these models is reported. Both the segmentation performance and the adapted image quality metrics were evaluated. RESULTS Regarding the segmentation Dice score, the proposed model ssppg achieves a significant improvement of 46.24% compared to without adaptation and reaches 87.4% of the upper limit of the segmentation performance. Furthermore, image quality metrics, including FID and KID scores, indicate that adapted images with better segmentation also have better image qualities. CONCLUSION The proposed method demonstrates the effectiveness of segmentation-driven domain adaptation in retinal imaging processing. It reduces the labor cost of manual labeling, incorporates prior anatomic information to regulate and guide domain adaptation, and provides insights into improving segmentation qualities in image domains without labels.
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Affiliation(s)
- Shuo Chen
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada.
| | - Da Ma
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada; Department of Internal Medicine, Section of Gerontology and Geriatric Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA; Center for Biomedical Informatics, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA; Alzheimer's Disease Research Center, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.
| | - Sieun Lee
- Mental Health & Clinical Neuroscience, School of Medicine, University of Nottingham, Nottingham, UK; Precision Imaging Beacon, University of Nottingham, Nottingham, UK
| | - Timothy T L Yu
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Gavin Xu
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Donghuan Lu
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada; Tencent Jarvis Lab, Shenzhen, China
| | - Karteek Popuri
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada; Department of Computer Science, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Myeong Jin Ju
- School of Biomedical Engineering, University of British Columbia, BC, Canada; Department of Ophthalmology & Visual Sciences, The University of British Columbia, Vancouver, BC, Canada
| | - Marinko V Sarunic
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada; Institute of Ophthalmology, University College London, London, UK; Department of Medical Physics and Biomedical Engineering, University College London, UK
| | - Mirza Faisal Beg
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada.
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8
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Miao Y, Song J, Ju MJ. Image-based cross-calibration method for multiple spectrometer-based OCT. Opt Lett 2022; 47:5096-5099. [PMID: 36181195 DOI: 10.1364/ol.468707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
A fast and practical computational cross-calibration of multiple spectrometers is described. A signal correlation matrix (CM) can be constructed from paired B-scans in a multiple-spectrometer optical coherence tomography (OCT), where the wavelength-corresponding pixels are indicated by high cross correlation. The CM can be used to either guide the physical alignment of spectrometers or to numerically match the spectra in the post-process. The performance is comparable to the previously reported optimization approach, as demonstrated by the mirror tests, qualitative comparison of OCT and optical coherence tomography angiography (OCTA) images, and quantitative comparison of image metrics.
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9
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Khan S, Neuhaus K, Thaware O, Ni S, Ju MJ, Redd T, Huang D, Jian Y. Corneal imaging with blue-light optical coherence microscopy. Biomed Opt Express 2022; 13:5004-5014. [PMID: 36187260 PMCID: PMC9484440 DOI: 10.1364/boe.465707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 08/17/2022] [Accepted: 08/17/2022] [Indexed: 06/16/2023]
Abstract
Corneal imaging is important for the diagnostic and therapeutic evaluation of many eye diseases. Optical coherence tomography (OCT) is extensively used in ocular imaging due to its non-invasive and high-resolution volumetric imaging characteristics. Optical coherence microscopy (OCM) is a technical variation of OCT that can image the cornea with cellular resolution. Here, we demonstrate a blue-light OCM as a low-cost and easily reproducible system to visualize corneal cellular structures such as epithelial cells, endothelial cells, keratocytes, and collagen bundles within stromal lamellae. Our blue-light OCM system achieved an axial resolution of 12 µm in tissue over a 1.2 mm imaging depth, and a lateral resolution of 1.6 µm over a field of view of 750 µm × 750 µm.
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Affiliation(s)
- Shanjida Khan
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | - Kai Neuhaus
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Omkar Thaware
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | - Shuibin Ni
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | - Myeong Jin Ju
- Department of Ophthalmology and Visual
Sciences, University of British Columbia,
Vancouver, BC, Canada
- School of Biomedical Engineering,
University of British Columbia, Vancouver,
BC, Canada
| | - Travis Redd
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - David Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
| | - Yifan Jian
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Biomedical Engineering, Oregon Health & Science University, Portland, OR 97239, USA
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10
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Xu QA, Athwal A, Heisler M, Ju MJ, Vanzan V, Ferrara D, Sarunic M, Navajas EV. ADAPTIVE OPTICS OPTICAL COHERENCE TOMOGRAPHY IN A CASE OF ACUTE ZONAL OCCULT OUTER RETINOPATHY. Retin Cases Brief Rep 2022; 16:435-438. [PMID: 32271274 DOI: 10.1097/icb.0000000000001000] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
PURPOSE To report a case of acute zonal occult outer retinopathy in which adaptive optics (AO) facilitated visualization of abnormal photoreceptors previously thought to be in an area of normal retina on conventional optical coherence tomography (OCT). METHODS Case report. RESULTS A 51-year-old woman presents with 11-month history of photopsias and scotoma in the temporal visual field of her left eye. Ocular imaging including fluorescein angiography, fundus autofluorescence and OCT suggested the diagnosis of acute zonal occult outer retinopathy in the left eye. Adaptive optics optical coherence tomography (AO-OCT) revealed photoreceptor abnormalities not previously identified in conventional OCT, in areas apparently normal on multimodal imaging. On enface and cross-sectional AO-OCT, round and evenly spaced hyperreflectivity corresponding to normal cone mosaic (Pattern 1) was adjacent to unevenly and disrupted cone hyperreflectivity (Pattern 2) and areas with hyporeflectivity or no cone reflectivity (Pattern 3). Cross-sectional AO-OCT of Patterns 2 and 3 also revealed attenuation of ellipsoid zone with loss of interdigitation zone. CONCLUSION Adaptive optics OCT documented cone photoreceptors in finer details than conventional OCT and revealed early changes in a patient with acute zonal occult outer retinopathy, in an area of the retina thought to be normal on conventional multimodal imaging. These findings may provide important insight into pathogenesis and progression of the disease.
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Affiliation(s)
- Qinyuan Alis Xu
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Arman Athwal
- School of Engineering, Simon Fraser University, Vancouver, British Columbia Canada; and
| | - Morgan Heisler
- School of Engineering, Simon Fraser University, Vancouver, British Columbia Canada; and
| | - Myeong Jin Ju
- School of Engineering, Simon Fraser University, Vancouver, British Columbia Canada; and
| | - Vinicius Vanzan
- School of Engineering, Simon Fraser University, Vancouver, British Columbia Canada; and
| | - Daniela Ferrara
- Department of Ophthalmology, Tufts University School of Medicine, Boston, British Columbia, Massachusetts
| | - Marinko Sarunic
- School of Engineering, Simon Fraser University, Vancouver, British Columbia Canada; and
| | - Eduardo V Navajas
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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11
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Ma D, Kumar M, Khetan V, Sen P, Bhende M, Chen S, Yu TTL, Lee S, Navajas EV, Matsubara JA, Ju MJ, Sarunic MV, Raman R, Beg MF. Clinical explainable differential diagnosis of polypoidal choroidal vasculopathy and age-related macular degeneration using deep learning. Comput Biol Med 2022; 143:105319. [PMID: 35220077 DOI: 10.1016/j.compbiomed.2022.105319] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 02/06/2023]
Abstract
BACKGROUND This study aims to achieve an automatic differential diagnosis between two types of retinal pathologies with similar pathological features - Polypoidal choroidal vasculopathy (PCV) and wet age-related macular degeneration (AMD) from volumetric optical coherence tomography (OCT) images, and identify clinically-relevant pathological features, using an explainable deep-learning-based framework. METHODS This is a retrospective study with data from a cross-sectional cohort. The OCT volume of 73 eyes from 59 patients was included in this study. Disease differentiation was achieved through single-B-scan-based classification followed by a volumetric probability prediction aggregation step. We compared different labeling strategies with and without identifying pathological B-scans within each OCT volume. Clinical interpretability was achieved through normalized aggregation of B-scan-based saliency maps followed by maximum-intensity-projection onto the en face plane. We derived the PCV score from the proposed differential diagnosis framework with different labeling strategies. The en face projection of saliency map was validated with the pathologies identified in Indocyanine green angiography (ICGA). RESULTS Model trained with both labeling strategies achieved similar level differentiation power (>90%), with good correspondence between pathological features detected from the projected en face saliency map and ICGA. CONCLUSIONS This study demonstrated the potential clinical application of non-invasive differential diagnosis using AI-driven OCT-based analysis, with minimal requirement of labeling efforts, along with clinical explainability achieved through automatically detected disease-related pathologies.
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Affiliation(s)
- Da Ma
- Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC, USA; School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada.
| | - Meenakshi Kumar
- Shri Bhagwan Mahavir Vitreoretinal Service, Medical Research Foundation, Sankara Nethralaya, Chennai, India
| | - Vikas Khetan
- Shri Bhagwan Mahavir Vitreoretinal Service, Medical Research Foundation, Sankara Nethralaya, Chennai, India
| | - Parveen Sen
- Shri Bhagwan Mahavir Vitreoretinal Service, Medical Research Foundation, Sankara Nethralaya, Chennai, India
| | - Muna Bhende
- Shri Bhagwan Mahavir Vitreoretinal Service, Medical Research Foundation, Sankara Nethralaya, Chennai, India
| | - Shuo Chen
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Timothy T L Yu
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Sieun Lee
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada; Mental Health & Clinical Neurosciences, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Eduardo V Navajas
- Department of Ophthalmology & Visual Sciences, The University of British Columbia, Vancouver, BC, Canada; University of British Columbia Vancouver General Hospital, Eye Care Centre, Vancouver, BC, Canada
| | - Joanne A Matsubara
- Department of Ophthalmology & Visual Sciences, The University of British Columbia, Vancouver, BC, Canada; University of British Columbia Vancouver General Hospital, Eye Care Centre, Vancouver, BC, Canada
| | - Myeong Jin Ju
- Department of Ophthalmology & Visual Sciences, The University of British Columbia, Vancouver, BC, Canada; University of British Columbia Vancouver General Hospital, Eye Care Centre, Vancouver, BC, Canada; School of Biomedical Engineering, University of British Columbia, BC, Canada
| | - Marinko V Sarunic
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada; Institute of Ophthalmology, University College London, London, UK; Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom
| | - Rajiv Raman
- Shri Bhagwan Mahavir Vitreoretinal Service, Medical Research Foundation, Sankara Nethralaya, Chennai, India.
| | - Mirza Faisal Beg
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada.
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12
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Miao Y, Song J, Hsu D, Ng R, Jian Y, Sarunic MV, Ju MJ. Numerical calibration method for a multiple spectrometer-based OCT system. Biomed Opt Express 2022; 13:1685-1701. [PMID: 35414988 PMCID: PMC8973183 DOI: 10.1364/boe.450942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/14/2022] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
The present paper introduces a numerical calibration method for the easy and practical implementation of multiple spectrometer-based spectral-domain optical coherence tomography (SD-OCT) systems. To address the limitations of the traditional hardware-based spectrometer alignment across more than one spectrometer, we applied a numerical spectral calibration algorithm where the pixels corresponding to the same wavelength in each unit are identified through spatial- and frequency-domain interferometric signatures of a mirror sample. The utility of dual spectrometer-based SD-OCT imaging is demonstrated through in vivo retinal imaging at two different operation modes with high-speed and dual balanced acquisitions, respectively, in which the spectral alignment is critical to achieve improved retinal image data without any artifacts caused by misalignment of the spectrometers.
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Affiliation(s)
- Yusi Miao
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Jun Song
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
| | - Destiny Hsu
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Ringo Ng
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Yifan Jian
- Casey Eye Institute, Oregon Health and Science University, Portland, Oregon 97239, USA
| | - Marinko V. Sarunic
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
- Institute of Ophthalmology, University College London, London, UK
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Myeong Jin Ju
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
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13
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Yu TT, Ma D, Lo J, Ju MJ, Beg MF, Sarunic MV. Effect of optical coherence tomography and angiography sampling rate towards diabetic retinopathy severity classification. Biomed Opt Express 2021; 12:6660-6673. [PMID: 34745763 PMCID: PMC8547994 DOI: 10.1364/boe.431992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/12/2021] [Accepted: 08/16/2021] [Indexed: 06/13/2023]
Abstract
Optical coherence tomography (OCT) and OCT angiography (OCT-A) may benefit the screening of diabetic retinopathy (DR). This study investigated the effect of laterally subsampling OCT/OCT-A en face scans by up to a factor of 8 when using deep neural networks for automated referable DR classification. There was no significant difference in the classification performance across all evaluation metrics when subsampling up to a factor of 3, and only minimal differences up to a factor of 8. Our findings suggest that OCT/OCT-A can reduce the number of samples (and hence the acquisition time) for a volume for a given field of view on the retina that is acquired for rDR classification.
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Affiliation(s)
- Timothy T. Yu
- Engineering Science, Simon Fraser University, Burnaby BC V5A1S6, Canada
| | - Da Ma
- Engineering Science, Simon Fraser University, Burnaby BC V5A1S6, Canada
| | - Julian Lo
- Engineering Science, Simon Fraser University, Burnaby BC V5A1S6, Canada
| | - Myeong Jin Ju
- Dept. of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, V5Z 3N9, Canada
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC, V5Z 3N9, Canada
| | - Mirza Faisal Beg
- Engineering Science, Simon Fraser University, Burnaby BC V5A1S6, Canada
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14
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Miao Y, Siadati M, Song J, Ma D, Jian Y, Beg MF, Sarunic MV, Ju MJ. Phase-corrected buffer averaging for enhanced OCT angiography using FDML laser. Opt Lett 2021; 46:3833-3836. [PMID: 34388753 DOI: 10.1364/ol.430915] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/07/2021] [Indexed: 05/18/2023]
Abstract
Megahertz-rate optical coherence tomography angiography (OCTA) is highly anticipated as an ultrafast imaging tool in clinical settings. However, shot-noise-limited sensitivity is inevitably reduced in high-speed imaging systems. In this Letter, we present a coherent buffer averaging technique for use with a Fourier-domain mode-locked (FDML) laser to improve OCTA contrast at 1060 nm MHz-rate retinal imaging. Full characterization of spectral variations among the FDML buffers and a numerical correction method are also presented, with the results demonstrating a 10-fold increase in the phase alignment among buffers. Coherent buffer averaging provided better OCTA contrast than the conventional multi-frame averaging approach with a faster acquisition time.
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15
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Bhalla M, Heisler M, Mammo Z, Ju MJ, Sarunic MV, Navajas EV, Warner S, Schendel S, Gill KS. Investigation of the Peripapillary Choriocapillaris in Normal Tension Glaucoma, Primary Open-angle Glaucoma, and Control Eyes. J Glaucoma 2021; 30:682-689. [PMID: 33927150 DOI: 10.1097/ijg.0000000000001861] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 04/01/2021] [Indexed: 11/26/2022]
Abstract
PRECIS The peripapillary choriocapillaris (CC) was observed to be significantly impaired in normal tension glaucoma (NTG) subjects compared with normal controls using optical coherence tomography angiography (OCTA). PURPOSE The aim was to quantitatively evaluate the peripapillary CC in NTG, primary open-angle glaucoma (POAG), and control eyes using OCTA. MATERIALS AND METHODS Ninety eyes (30 controls, 30 NTG, and 30 POAG) from 73 patients were imaged using the Zeiss Plex Elite 9000. Five repeat 3×3 mm OCTA scans were acquired both nasally and temporally to the optic disc and subsequently averaged. Four CC flow deficit (FD) measures were calculated using the fuzzy C-means approach: FD density (FDD), mean FD size (MFDS), FD number (FDN), and FD area (FDA). RESULTS Temporal NTG CC parameters were associated with visual field index and mean deviation (P<0.05). The control group showed a significantly lower nasal FDD (nasal: 3.79±1.26%, temporal: 4.48±1.73%, P=0.03), FDN (nasal: 156.43±38.44, temporal: 178.40±45.68, P=0.02), and FDA (nasal: 0.22±0.08, temporal: 0.26±0.10, P=0.03) when compared with temporal optic disc. The NTG group showed a significantly higher FDD (NTG: 5.04±2.38%, control: 3.79±1.26%, P=0.03), FDN (NTG: 185.90±56.66, control: 156.43±38.44, P=0.04), and FDA (NTG: 0.30±0.14 mm2, control: 0.22±0.08 mm2, P=0.03) nasal to the optic disc compared with controls. CONCLUSIONS Association between CC parameters and glaucoma severity in NTG, but not POAG subjects, suggests vascular abnormalities may be a potential factor in the multifactorial process of glaucoma damage in NTG patients.
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Affiliation(s)
| | - Morgan Heisler
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Zaid Mammo
- Department of Ophthalmology and Visual Sciences
| | - Myeong Jin Ju
- Department of Ophthalmology and Visual Sciences
- School of Biomedical Engineering, University of British Columbia, Vancouver
| | - Marinko V Sarunic
- School of Engineering Science, Simon Fraser University, Burnaby, BC, Canada
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16
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Athwal A, Balaratnasingam C, Yu DY, Heisler M, Sarunic MV, Ju MJ. Optimizing 3D retinal vasculature imaging in diabetic retinopathy using registration and averaging of OCT-A. Biomed Opt Express 2021; 12:553-570. [PMID: 33659089 PMCID: PMC7899521 DOI: 10.1364/boe.408590] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/06/2020] [Accepted: 12/07/2020] [Indexed: 05/29/2023]
Abstract
High resolution visualization of optical coherence tomography (OCT) and OCT angiography (OCT-A) data is required to fully take advantage of the imaging modality's three-dimensional nature. However, artifacts induced by patient motion often degrade OCT-A data quality. This is especially true for patients with deteriorated focal vision, such as those with diabetic retinopathy (DR). We propose a novel methodology for software-based OCT-A motion correction achieved through serial acquisition, volumetric registration, and averaging. Motion artifacts are removed via a multi-step 3D registration process, and visibility is significantly enhanced through volumetric averaging. We demonstrate that this method permits clear 3D visualization of retinal pathologies and their surrounding features, 3D visualization of inner retinal capillary connections, as well as reliable visualization of the choriocapillaris layer.
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Affiliation(s)
- Arman Athwal
- School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Chandrakumar Balaratnasingam
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Dao-Yi Yu
- Centre for Ophthalmology and Visual Science, University of Western Australia, Perth, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Morgan Heisler
- School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Marinko V. Sarunic
- School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
| | - Myeong Jin Ju
- School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada
- University of British Columbia, Department of Ophthalmology and Visual Sciences, 2550 Willow Street, Vancouver, BC, V5Z 3N9, Canada
- University of British Columbia, School of Biomedical Engineering, 251–2222 Health Sciences Mall, Vancouver, BC, V6 T 1Z3, Canada
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17
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Hsu D, Kwon JH, Ng R, Makita S, Yasuno Y, Sarunic MV, Ju MJ. Quantitative multi-contrast in vivo mouse imaging with polarization diversity optical coherence tomography and angiography. Biomed Opt Express 2020; 11:6945-6961. [PMID: 33408972 PMCID: PMC7747897 DOI: 10.1364/boe.403209] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 10/15/2020] [Accepted: 10/31/2020] [Indexed: 05/02/2023]
Abstract
Retinal microvasculature and the retinal pigment epithelium (RPE) play vital roles in maintaining the health and metabolic activity of the eye. Visualization of these retina structures is essential for pre-clinical studies of vision-robbing diseases, such as age-related macular degeneration (AMD). We have developed a quantitative multi-contrast polarization diversity OCT and angiography (QMC-PD-OCTA) system for imaging and visualizing pigment in the RPE using degree of polarization uniformity (DOPU), along with flow in the retinal capillaries using OCT angiography (OCTA). An adaptive DOPU averaging kernel was developed to increase quantifiable values from visual data, and QMC en face images permit simultaneous visualization of vessel location, depth, melanin region thickness, and mean DOPU values, allowing rapid identification and differentiation of disease symptoms. The retina of five different mice strains were measured in vivo, with results demonstrating potential for pre-clinical studies of retinal disorders.
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Affiliation(s)
- Destiny Hsu
- Simon Fraser University, Biomedical Optics Research Group, Department of Engineering Science, Burnaby, British Columbia, Canada
- co-first author
| | - Ji Hoon Kwon
- Simon Fraser University, Biomedical Optics Research Group, Department of Engineering Science, Burnaby, British Columbia, Canada
- co-first author
| | - Ringo Ng
- Simon Fraser University, Biomedical Optics Research Group, Department of Engineering Science, Burnaby, British Columbia, Canada
| | - Shuichi Makita
- University of Tsukuba, Computational Optics Group, Institute of Applied Physics, Japan
| | - Yoshiaki Yasuno
- University of Tsukuba, Computational Optics Group, Institute of Applied Physics, Japan
| | - Marinko V. Sarunic
- Simon Fraser University, Biomedical Optics Research Group, Department of Engineering Science, Burnaby, British Columbia, Canada
| | - Myeong Jin Ju
- Simon Fraser University, Biomedical Optics Research Group, Department of Engineering Science, Burnaby, British Columbia, Canada
- University of British Columbia, Department of Ophthalmology and Visual Sciences, Vancouver, British Columbia, Canada
- University of British Columbia, School of Biomedical Engineering, Vancouver, British Columbia, Canada
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18
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Heisler M, Bhalla M, Lo J, Mammo Z, Lee S, Ju MJ, Beg MF, Sarunic MV. Semi-supervised deep learning based 3D analysis of the peripapillary region. Biomed Opt Express 2020; 11:3843-3856. [PMID: 33014570 PMCID: PMC7510893 DOI: 10.1364/boe.392648] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 05/08/2023]
Abstract
Optical coherence tomography (OCT) has become an essential tool in the evaluation of glaucoma, typically through analyzing retinal nerve fiber layer changes in circumpapillary scans. Three-dimensional OCT volumes enable a much more thorough analysis of the optic nerve head (ONH) region, which may be the site of initial glaucomatous optic nerve damage. Automated analysis of this region is of great interest, though large anatomical variations and the termination of layers make the requisite peripapillary layer and Bruch's membrane opening (BMO) segmentation a challenging task. Several machine learning-based segmentation methods have been proposed for retinal layer segmentation, and a few for the ONH region, but they typically depend on either heavily averaged or pre-processed B-scans or a large amount of annotated data, which is a tedious task and resource-intensive. We evaluated a semi-supervised adversarial deep learning method for segmenting peripapillary retinal layers in OCT B-scans to take advantage of unlabeled data. We show that the use of a generative adversarial network and unlabeled data can improve the performance of segmentation. Additionally, we use a Faster R-CNN architecture to automatically segment the BMO. The proposed methods are then used for the 3D morphometric analysis of both control and glaucomatous ONH volumes to demonstrate the potential for clinical utility.
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Affiliation(s)
- Morgan Heisler
- Simon Fraser University, Department of
Engineering Science, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Mahadev Bhalla
- University of British Columbia, Faculty of
Medicine, 317-2194 Health Sciences Mall, Vancouver, BC, V6 T 1Z3,
Canada
| | - Julian Lo
- Simon Fraser University, Department of
Engineering Science, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Zaid Mammo
- University of British Columbia, Department
of Ophthalmology and Vision Science, 2550 Willow Street, Vancouver,
BC, V5Z 3N9, Canada
| | - Sieun Lee
- Simon Fraser University, Department of
Engineering Science, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Myeong Jin Ju
- University of British Columbia, Department
of Ophthalmology and Vision Science, 2550 Willow Street, Vancouver,
BC, V5Z 3N9, Canada
- University of British Columbia, School of
Biomedical Engineering, 251-2222 Health Sciences Mall, Vancouver, BC,
V6 T 1Z3, Canada
| | - Mirza Faisal Beg
- Simon Fraser University, Department of
Engineering Science, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Marinko V. Sarunic
- Simon Fraser University, Department of
Engineering Science, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
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19
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Wahl DJ, Ju MJ, Jian Y, Sarunic MV. Non-invasive cellular-resolution retinal imaging with two-photon excited fluorescence. Biomed Opt Express 2019; 10:4859-4873. [PMID: 31565530 PMCID: PMC6757458 DOI: 10.1364/boe.10.004859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/13/2019] [Accepted: 08/13/2019] [Indexed: 05/02/2023]
Abstract
Two-photon excited fluorescence (TPEF) imaging of the retina is a developing technique that provides non-invasive compound-specific measurements from the retina. In this report, we demonstrate high-resolution TPEF imaging of the mouse retina using sensorless adaptive optics (SAO) and optical coherence tomography (OCT). A single near-infrared light source was used for simultaneous multi-modal imaging with OCT and TPEF. The image-based SAO could be performed using the en face OCT or the TPEF for aberration correction. Our results demonstrate OCT and TPEF for angiography. Also, we demonstrate non-invasive cellular-resolution imaging of fluorescently labelled cells and the Retinal Pigment Epithelium (RPE) mosaic.
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Affiliation(s)
- Daniel J. Wahl
- Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Myeong Jin Ju
- Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Yifan Jian
- Engineering Science, Simon Fraser University, Burnaby, BC, Canada
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
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20
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Meleppat RK, Zhang P, Ju MJ, Manna SK, Jian Y, Pugh EN, Zawadzki RJ. Directional optical coherence tomography reveals melanin concentration-dependent scattering properties of retinal pigment epithelium. J Biomed Opt 2019; 24:1-10. [PMID: 31254332 PMCID: PMC6977406 DOI: 10.1117/1.jbo.24.6.066011] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 05/30/2019] [Indexed: 05/18/2023]
Abstract
Optical coherence tomography (OCT) is a powerful tool in ophthalmology that provides in vivo morphology of the retinal layers and their light scattering properties. The directional (angular) reflectivity of the retinal layers was investigated with focus on the scattering from retinal pigment epithelium (RPE). The directional scattering of the RPE was studied in three mice strains with three distinct melanin concentrations: albino (BALB/c), agouti (129S1/SvlmJ), and strongly pigmented (C57BL/6J). The backscattering signal strength was measured with a directional OCT system in which the pupil entry position of the narrow OCT beam can be varied across the dilated pupil of the eyes of the mice. The directional reflectivity of other retinal melanin-free layers, including the internal and external limiting membranes, and Bruch's membrane (albinos) were also measured and compared between the strains. The intensity of light backscattered from these layers was found highly sensitive to the angle of illumination, whereas the inner/outer segment (IS/OS) junctions showed a reduced sensitivity. The reflections from the RPE are largely insensitive in highly pigmented mice. The differences in directional scattering between strains shows that directionality decreases with an increase in melanin concentrations in RPE, suggesting increasing contribution of Mie scattering by melanosomes.
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Affiliation(s)
- Ratheesh K. Meleppat
- University of California Davis, UC Davis Eyepod, Department of Cell Biology and Human Anatomy, Davis, California, United States
| | - Pengfei Zhang
- University of California Davis, UC Davis Eyepod, Department of Cell Biology and Human Anatomy, Davis, California, United States
| | - Myeong Jin Ju
- Simon Fraser University, School of Engineering Science, Burnaby, British Columbia, Canada
| | - Suman K. Manna
- University of California Davis, UC Davis Eyepod, Department of Cell Biology and Human Anatomy, Davis, California, United States
| | - Yifan Jian
- Oregon Science and Health University, Casey Eye Institute, Portland, Oregon, United States
| | - Edward N. Pugh
- University of California Davis, UC Davis Eyepod, Department of Cell Biology and Human Anatomy, Davis, California, United States
| | - Robert J. Zawadzki
- University of California Davis, UC Davis Eyepod, Department of Cell Biology and Human Anatomy, Davis, California, United States
- University of California Davis, UC Davis Eye Center, Department of Ophthalmology and Vision Science, Sacramento, California, United States
- Address all correspondence to Robert J. Zawadzki, E-mail:
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21
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Ju MJ, Hsu D, Kwon JH, Wahl DJ, Bonora S, Jian Y, Makita S, Yasuno Y, Sarunic MV. Multi-scale and -contrast sensorless adaptive optics optical coherence tomography. Quant Imaging Med Surg 2019; 9:757-768. [PMID: 31281772 DOI: 10.21037/qims.2019.05.17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Background The roles of the retinal microvasculature and the retinal pigment epithelium (RPE) in maintaining the health and metabolic activity of the retina lend great clinical value to their high-resolution visualization. Methods By integrating polarization diversity detection (PDD) into multi-scale and -contrast sensorless adaptive optics optical coherence tomography (MSC-SAO-OCT), we have developed a novel multi-contrast SAO OCT system for imaging pigment in the RPE as well as flow in the retinal capillaries using OCT angiography (OCTA). Aberration correction was performed based on the image quality using transmissive deformable optical elements. Results MSC-SAO-OCTA imaging was performed at multiple fields-of-view (FOVs) with adjustable numerical aperture (NA). Retinal flow and RPE structural images for in vivo healthy and pathological human posterior eyes were demonstrated to show clinical feasibility of the system. Conclusions High-resolution imaging of retinal vasculature at both large and small FOVs, as well as characterization of RPE topology and deformation, enables more sophisticated and concise investigation of retinal pathologies for in vivo human imaging. MSC imaging may permit detection and analysis of even subtle deformations in the RPE layer using a single instrument.
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Affiliation(s)
- Myeong Jin Ju
- Department of Engineering Science, Simon Fraser University, Burnaby, Canada.,Beckman Laser Institute-Korea, College of Medicine, Dankook University, Cheonan, South Korea
| | - Destiny Hsu
- Department of Engineering Science, Simon Fraser University, Burnaby, Canada
| | - Ji Hoon Kwon
- Department of Engineering Science, Simon Fraser University, Burnaby, Canada
| | - Daniel J Wahl
- Department of Engineering Science, Simon Fraser University, Burnaby, Canada
| | - Stefano Bonora
- CNR-Institute for Photonics and Nanotechnology, Padova, Italy
| | - Yifan Jian
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Shuichi Makita
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Marinko V Sarunic
- Department of Engineering Science, Simon Fraser University, Burnaby, Canada
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Zhou X, Ju MJ, Huang L, Tang S. Slope-based segmentation of articular cartilage using polarization-sensitive optical coherence tomography phase retardation image. J Biomed Opt 2019; 24:1-14. [PMID: 30873765 PMCID: PMC6975236 DOI: 10.1117/1.jbo.24.3.036006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/02/2019] [Indexed: 05/14/2023]
Abstract
A segmentation method based on phase retardation measurements from polarization-sensitive optical coherence tomography (PS-OCT) is developed to differentiate the structural zones of articular cartilage. The organization of collagen matrix in articular cartilage varies over the different structural zones, generating different tissue birefringence. Analyzing the slope of the accumulated phase retardation at different depths can detect the variation in tissue birefringence and be used to segment the structural zones. The method is validated on phantoms composed of layers of different materials. Articular cartilage samples from adult swine are segmented with the method. The characteristics in each segmented zone are also examined by histology and high-resolution second-harmonic generation imaging, showing distinctive properties that match with the anatomical structure of articular cartilage. The segmentation algorithm is also applied on PS-OCT images acquired at multiple illumination angles, where the angular dependence of tissue birefringence in the deep zone is detected. This method offers a noninvasive imaging approach to differentiating the structural zones of articular cartilage, as well as a quantification approach based on the phase retardation measurements of PS-OCT. This method has great potential in studying depth-related progression of cartilage degeneration.
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Affiliation(s)
- Xin Zhou
- University of British Columbia, Department of Electrical and Computer Engineering, Vancouver, British Columbia, Canada
| | - Myeong Jin Ju
- Simon Fraser University, School of Engineering Science, Burnaby, British Columbia, Canada
- Beckman Laser Institute-Korea, Dankook University, Cheonan, Chungnam, South Korea
| | - Lin Huang
- University of British Columbia, Department of Electrical and Computer Engineering, Vancouver, British Columbia, Canada
| | - Shuo Tang
- University of British Columbia, Department of Electrical and Computer Engineering, Vancouver, British Columbia, Canada
- Address all correspondence to Shuo Tang, E-mail:
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23
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Wahl DJ, Ng R, Ju MJ, Jian Y, Sarunic MV. Sensorless adaptive optics multimodal en-face small animal retinal imaging. Biomed Opt Express 2019; 10:252-267. [PMID: 30775098 PMCID: PMC6363194 DOI: 10.1364/boe.10.000252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 11/26/2018] [Accepted: 11/27/2018] [Indexed: 05/18/2023]
Abstract
Vision researchers often use small animals due to the availability of many transgenic strains that model human diseases or express biomarkers. Adaptive optics (AO) enables non-invasive single-cell imaging in a living animal but often results in high system complexity. Sensorless AO (SAO) can provide depth-resolved aberration correction with low system complexity. We present a multi-modal sensorless AO en face retina imaging system that includes optical coherence tomography (OCT), OCT-angiography, confocal scanning laser ophthalmoscopy (SLO), and fluorescence detection. We present a compact lens-based imaging system design that allows for a 50-degree maximum field of view (FOV), which can be reduced to the region of interest to perform SAO with the modality of choice. The system performance was demonstrated on wild type mice (C57BL/6J), and transgenic mice with GFP labeled cells. SAO SLO was used for imaging microglia (Cx3cr1-GFP) over ~1 hour, where dynamics of the microglia branches were clearly observed. Our results also include volumetric cellular imaging of microglia throughout the inner retina.
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Affiliation(s)
- Daniel J. Wahl
- Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Ringo Ng
- Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Myeong Jin Ju
- Engineering Science, Simon Fraser University, Burnaby, BC, Canada
| | - Yifan Jian
- Engineering Science, Simon Fraser University, Burnaby, BC, Canada
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
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24
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Heisler M, Ju MJ, Bhalla M, Schuck N, Athwal A, Navajas EV, Beg MF, Sarunic MV. Automated identification of cone photoreceptors in adaptive optics optical coherence tomography images using transfer learning. Biomed Opt Express 2018; 9:5353-5367. [PMID: 30460133 PMCID: PMC6238943 DOI: 10.1364/boe.9.005353] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/01/2018] [Accepted: 10/02/2018] [Indexed: 05/11/2023]
Abstract
Automated measurements of the human cone mosaic requires the identification of individual cone photoreceptors. The current gold standard, manual labeling, is a tedious process and can not be done in a clinically useful timeframe. As such, we present an automated algorithm for identifying cone photoreceptors in adaptive optics optical coherence tomography (AO-OCT) images. Our approach fine-tunes a pre-trained convolutional neural network originally trained on AO scanning laser ophthalmoscope (AO-SLO) images, to work on previously unseen data from a different imaging modality. On average, the automated method correctly identified 94% of manually labeled cones when compared to manual raters, from twenty different AO-OCT images acquired from five normal subjects. Voronoi analysis confirmed the general hexagonal-packing structure of the cone mosaic as well as the general cone density variability across portions of the retina. The consistency of our measurements demonstrates the high reliability and practical utility of having an automated solution to this problem.
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Affiliation(s)
- Morgan Heisler
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Myeong Jin Ju
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Mahadev Bhalla
- University of British Columbia, Faculty of Medicine, 317 - 2194 Health Sciences Mall, Vancouver, BC, V6T 1Z3,
Canada
| | - Nathan Schuck
- University of British Columbia, Faculty of Medicine, 317 - 2194 Health Sciences Mall, Vancouver, BC, V6T 1Z3,
Canada
| | - Arman Athwal
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Eduardo V. Navajas
- University of British Columbia, Department of Ophthalmology & Vision Science, 2550 Willow Street, Vancouver, BC, V5Z 3N9,
Canada
| | - Mirza Faisal Beg
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Marinko V. Sarunic
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
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25
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Ju MJ, Huang C, Wahl DJ, Jian Y, Sarunic MV. Visible light sensorless adaptive optics for retinal structure and fluorescence imaging. Opt Lett 2018; 43:5162-5165. [PMID: 30320845 DOI: 10.1364/ol.43.005162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Optical coherence tomography (OCT) has emerged as a powerful imaging instrument and technology in biomedicine. OCT imaging is predominantly performed using wavelengths in the near infrared; however, visible light (VIS) has been recently employed in OCT systems with encouraging results for high-resolution retinal imaging. Using a broadband supercontinuum VIS source, we present a sensorless adaptive optics (SAO) multimodal imaging system driven by VIS-OCT for volumetric retinal structural imaging, followed by the acquisition of fluorescence emission. The coherence-gated, depth-resolved VIS-OCT images used for image-guided SAO aberration correction enable high-resolution structural and fluorescence imaging.
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26
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Ju MJ, Heisler M, Athwal A, Sarunic MV, Jian Y. Effective bidirectional scanning pattern for optical coherence tomography angiography. Biomed Opt Express 2018; 9:2336-2350. [PMID: 29760992 PMCID: PMC5946793 DOI: 10.1364/boe.9.002336] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/17/2018] [Accepted: 04/17/2018] [Indexed: 05/18/2023]
Abstract
We demonstrate the utility of a novel scanning method for optical coherence tomography angiography (OCTA). Although raster scanning is commonly used for OCTA imaging, a bidirectional approach would lessen the distortion caused by galvanometer-based scanners as sources continue to increase sweep rates. As shown, a unidirectional raster scan approach has a lower effective scanning time than bidirectional approaches; however, a strictly bidirectional approach causes contrast variation along the B-scan direction due to the non-uniform time interval between B-scans. Therefore, a stepped bidirectional approach is introduced and successfully applied to retinal imaging in normal controls and in a pathological subject with diabetic retinopathy.
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27
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Ju MJ, Heisler M, Wahl D, Jian Y, Sarunic MV. Multiscale sensorless adaptive optics OCT angiography system for in vivo human retinal imaging. J Biomed Opt 2017; 22:1-10. [PMID: 29094524 DOI: 10.1117/1.jbo.22.12.121703] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 10/05/2017] [Indexed: 05/25/2023]
Abstract
We present a multiscale sensorless adaptive optics (SAO) OCT system capable of imaging retinal structure and vasculature with various fields-of-view (FOV) and resolutions. Using a single deformable mirror and exploiting the polarization properties of light, the SAO-OCT-A was implemented in a compact and easy to operate system. With the ability to adjust the beam diameter at the pupil, retinal imaging was demonstrated at two different numerical apertures with the same system. The general morphological structure and retinal vasculature could be observed with a few tens of micrometer-scale lateral resolution with conventional OCT and OCT-A scanning protocols with a 1.7-mm-diameter beam incident at the pupil and a large FOV (15 deg× 15 deg). Changing the system to a higher numerical aperture with a 5.0-mm-diameter beam incident at the pupil and the SAO aberration correction, the FOV was reduced to 3 deg× 3 deg for fine detailed imaging of morphological structure and microvasculature such as the photoreceptor mosaic and capillaries. Multiscale functional SAO-OCT imaging was performed on four healthy subjects, demonstrating its functionality and potential for clinical utility.
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Affiliation(s)
- Myeong Jin Ju
- Simon Fraser University, Department of Engineering Science, Burnaby, British Columbia, Canada
| | - Morgan Heisler
- Simon Fraser University, Department of Engineering Science, Burnaby, British Columbia, Canada
| | - Daniel Wahl
- Simon Fraser University, Department of Engineering Science, Burnaby, British Columbia, Canada
| | - Yifan Jian
- Simon Fraser University, Department of Engineering Science, Burnaby, British Columbia, Canada
| | - Marinko V Sarunic
- Simon Fraser University, Department of Engineering Science, Burnaby, British Columbia, Canada
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28
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Verstraete HRGW, Heisler M, Ju MJ, Wahl D, Bliek L, Kalkman J, Bonora S, Jian Y, Verhaegen M, Sarunic MV. Wavefront sensorless adaptive optics OCT with the DONE algorithm for in vivo human retinal imaging [Invited]. Biomed Opt Express 2017; 8:2261-2275. [PMID: 28736670 PMCID: PMC5516811 DOI: 10.1364/boe.8.002261] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 03/07/2017] [Accepted: 03/12/2017] [Indexed: 05/05/2023]
Abstract
In this report, which is an international collaboration of OCT, adaptive optics, and control research, we demonstrate the Data-based Online Nonlinear Extremum-seeker (DONE) algorithm to guide the image based optimization for wavefront sensorless adaptive optics (WFSL-AO) OCT for in vivo human retinal imaging. The ocular aberrations were corrected using a multi-actuator adaptive lens after linearization of the hysteresis in the piezoelectric actuators. The DONE algorithm succeeded in drastically improving image quality and the OCT signal intensity, up to a factor seven, while achieving a computational time of 1 ms per iteration, making it applicable for many high speed applications. We demonstrate the correction of five aberrations using 70 iterations of the DONE algorithm performed over 2.8 s of continuous volumetric OCT acquisition. Data acquired from an imaging phantom and in vivo from human research volunteers are presented.
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Affiliation(s)
- Hans R. G. W. Verstraete
- Delft Center for Systems and Control, Delft University of Technology, Mekelweg 2, 2628 CD, Delft, The
Netherlands
| | - Morgan Heisler
- School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Myeong Jin Ju
- School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Daniel Wahl
- School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
| | - Laurens Bliek
- Delft Center for Systems and Control, Delft University of Technology, Mekelweg 2, 2628 CD, Delft, The
Netherlands
| | - Jeroen Kalkman
- Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The
Netherlands
| | - Stefano Bonora
- Department of Imaging Physics, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The
Netherlands
| | - Yifan Jian
- School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
- These authors contributed equally
| | - Michel Verhaegen
- Delft Center for Systems and Control, Delft University of Technology, Mekelweg 2, 2628 CD, Delft, The
Netherlands
- These authors contributed equally
| | - Marinko V. Sarunic
- School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6,
Canada
- These authors contributed equally
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29
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Cua M, Lee S, Miao D, Ju MJ, Mackenzie PJ, Jian Y, Sarunic MV. Retinal optical coherence tomography at 1 μm with dynamic focus control and axial motion tracking. J Biomed Opt 2016; 21:26007. [PMID: 26882449 DOI: 10.1117/1.jbo.21.2.026007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 01/19/2016] [Indexed: 05/05/2023]
Abstract
High-resolution optical coherence tomography (OCT) retinal imaging is important to noninvasively visualize the various retinal structures to aid in better understanding of the pathogenesis of vision-robbing diseases. However, conventional OCT systems have a trade-off between lateral resolution and depth-of-focus. In this report, we present the development of a focus-stacking OCT system with automatic focus optimization for high-resolution, extended-focal-range clinical retinal imaging by incorporating a variable-focus liquid lens into the sample arm optics. Retinal layer tracking and selection was performed using a graphics processing unit accelerated processing platform for focus optimization, providing real-time layer-specific en face visualization. After optimization, multiple volumes focused at different depths were acquired, registered, and stitched together to yield a single, high-resolution focus-stacked dataset. Using this system, we show high-resolution images of the retina and optic nerve head, from which we extracted clinically relevant parameters such as the nerve fiber layer thickness and lamina cribrosa microarchitecture.
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Affiliation(s)
- Michelle Cua
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, British Columbia V5A1S6, Canada
| | - Sujin Lee
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, British Columbia V5A1S6, Canada
| | - Dongkai Miao
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, British Columbia V5A1S6, Canada
| | - Myeong Jin Ju
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, British Columbia V5A1S6, Canada
| | - Paul J Mackenzie
- University of British Columbia, Department of Ophthalmology and Visual Science, Eye Care Center, 2550 Willow Street, Vancouver, British Columbia V5Z 3N9, Canada
| | - Yifan Jian
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, British Columbia V5A1S6, Canada
| | - Marinko V Sarunic
- Simon Fraser University, Department of Engineering Science, 8888 University Drive, Burnaby, British Columbia V5A1S6, Canada
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Ju MJ, Tang S. Usage of polarization-sensitive optical coherence tomography for investigation of collagen cross-linking. J Biomed Opt 2015; 20:046001. [PMID: 25837511 DOI: 10.1117/1.jbo.20.4.046001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2014] [Accepted: 03/16/2015] [Indexed: 05/04/2023]
Abstract
To investigate morphological alternation in corneal stroma induced by collagen cross-linking (CXL) treatment, polarization-sensitive optical coherence tomography (PS-OCT) capable of providing scattering, phase retardation, and degree of polarization uniformity (DOPU) images were employed on fresh bovine cornea. Significant corneal thickness reduction was observed after the CXL procedure, and its variation was quantitatively analyzed. From the scattering contrast, a hyperscattering region was observed in the anterior of the cornea immediately after the CXL procedure and its range increased with time. Within the scattering region, a slow increase was observed in the phase retardation image, and a discriminable characteristic was found in the DOPU image. A global threshold value was empirically determined from the averaged DOPU depth profile in order to locate the effective cross-linking depth. In addition to the standard protocol, an accelerated CXL procedure shortening the treatment time with higher intensity of ultraviolet-A (UV-)A power was also performed. From the measurement results after the two different CXL protocols, different cross-linking aspects were found and their difference was discussed in terms of the effectiveness of cross-linking. Based on this study, we believe that PS-OCT could be a promising optical imaging modality to evaluate the progression and effectiveness of the riboflavin/UV-A induced corneal collagen cross-linking.
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Hong YJ, Miura M, Ju MJ, Makita S, Iwasaki T, Yasuno Y. Simultaneous Investigation of Vascular and Retinal Pigment Epithelial Pathologies of Exudative Macular Diseases by Multifunctional Optical Coherence Tomography. ACTA ACUST UNITED AC 2014; 55:5016-31. [DOI: 10.1167/iovs.14-14005] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Young-Joo Hong
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan 2Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan
| | - Masahiro Miura
- Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan 3Department of Ophthalmology, Ibaraki Medical Center, Tokyo Medical University, Ami, Ibaraki, Japan
| | - Myeong Jin Ju
- Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shuichi Makita
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan 2Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan
| | - Takuya Iwasaki
- Department of Ophthalmology, Ibaraki Medical Center, Tokyo Medical University, Ami, Ibaraki, Japan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan 2Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan
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Ju MJ, Shin JG, Hoshi S, Yasuno Y, Lee BH, Tang S, Eom TJ. Three-dimensional volumetric human meibomian gland investigation using polarization-sensitive optical coherence tomography. J Biomed Opt 2014; 19:30503. [PMID: 24604532 DOI: 10.1117/1.jbo.19.3.030503] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 02/05/2014] [Indexed: 06/03/2023]
Abstract
In this study, polarization-sensitive optical coherence tomography (PS-OCT) capable of providing polarization contrasts such as phase retardation and degree of polarization uniformity (DOPU) was used for visualizing human meibomian glands (MGs) and investigating morphological characteristics of them. Especially, with the help of the DOPU contrast, MGs were exclusively extracted from the volumetric OCT image. In vivo PS-OCT measurements were performed on the upper eyelids of different age groups. From these measurements, different age-dependent aspects of the MG structure were also observed. Based on these observations, it can be inferred that the PS-OCT system has the potential for clinical diagnosis and investigation of MG-related dry eye diseases like MG dysfunction (MGD) and acinar atrophy.
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Affiliation(s)
- Myeong Jin Ju
- University of British Columbia, Department of Electrical and Computer Engineering, 2332 Main Mall, Vancouver, BC, V6T 1Z4, CanadabUniversity of Tsukuba, Institute of Applied Physics, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8573, Japan
| | - Jun Geun Shin
- Gwangju Institute of Science and Technology, School of Information and Communication, 123 Cheomdan-gwagiro, Gwangju 500-712, Republic of Korea
| | - Sujin Hoshi
- University of Tsukuba, Institute of Applied Physics, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8573, JapandUniversity of Tsukuba, Faculty of Medicine, Department of Ophthalmology, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8575, Japan
| | - Yoshiaki Yasuno
- University of Tsukuba, Institute of Applied Physics, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8573, Japan
| | - Byeong Ha Lee
- Gwangju Institute of Science and Technology, School of Information and Communication, 123 Cheomdan-gwagiro, Gwangju 500-712, Republic of Korea
| | - Shuo Tang
- University of British Columbia, Department of Electrical and Computer Engineering, 2332 Main Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Tae Joong Eom
- Gwangju Institute of Science and Technology, Advanced Photonic Research Institute, 123 Cheomdan-gwagiro, Gwangju 500-712, Republic of Korea
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Ju MJ, Hong YJ, Makita S, Lim Y, Kurokawa K, Duan L, Miura M, Tang S, Yasuno Y. Advanced multi-contrast Jones matrix optical coherence tomography for Doppler and polarization sensitive imaging. Opt Express 2013; 21:19412-36. [PMID: 23938857 DOI: 10.1364/oe.21.019412] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
An advanced version of Jones matrix optical coherence tomography (JMT) is demonstrated for Doppler and polarization sensitive imaging of the posterior eye. JMT is capable of providing localized flow tomography by Doppler detection and investigating the birefringence property of tissue through a three-dimensional (3-D) Jones matrix measurement. Owing to an incident polarization multiplexing scheme based on passive optical components, this system is stable, safe in a clinical environment, and cost effective. Since the properties of this version of JMT provide intrinsic compensation for system imperfection, the system is easy to calibrate. Compared with the previous version of JMT, this advanced JMT achieves a sufficiently long depth measurement range for clinical cases of posterior eye disease. Furthermore, a fine spectral shift compensation method based on the cross-correlation of calibration signals was devised for stabilizing the phase of OCT, which enables a high sensitivity Doppler OCT measurement. In addition, a new theory of JMT which integrates the Jones matrix measurement, Doppler measurement, and scattering measurement is presented. This theory enables a sensitivity-enhanced scattering OCT and high-sensitivity Doppler OCT. These new features enable the application of this system to clinical cases. A healthy subject and a geographic atrophy patient were measured in vivo, and simultaneous imaging of choroidal vasculature and birefringence structures are demonstrated.
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Affiliation(s)
- Myeong Jin Ju
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
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Hong YJ, Miura M, Makita S, Ju MJ, Lee BH, Iwasaki T, Yasuno Y. Noninvasive Investigation of Deep Vascular Pathologies of Exudative Macular Diseases by High-Penetration Optical Coherence Angiography. ACTA ACUST UNITED AC 2013; 54:3621-31. [DOI: 10.1167/iovs.12-11184] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Young-Joo Hong
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan 2Computational Optics and Ophthalmology Group, Tsukuba, Japan
| | - Masahiro Miura
- Computational Optics and Ophthalmology Group, Tsukuba, Japan 3Department of Ophthalmology, Ibaraki Medical Center, Tokyo Medical University, Ami, Ibaraki, Japan
| | - Shuichi Makita
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan 2Computational Optics and Ophthalmology Group, Tsukuba, Japan
| | - Myeong Jin Ju
- School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Byeong Ha Lee
- School of Information and Communications, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Takuya Iwasaki
- Department of Ophthalmology, Ibaraki Medical Center, Tokyo Medical University, Ami, Ibaraki, Japan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan 2Computational Optics and Ophthalmology Group, Tsukuba, Japan
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Tang S, Zhou Y, Ju MJ. Multimodal optical imaging with multiphoton microscopy and optical coherence tomography. J Biophotonics 2012; 5:396-403. [PMID: 22461146 DOI: 10.1002/jbio.201100138] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 02/13/2012] [Accepted: 02/22/2012] [Indexed: 05/22/2023]
Abstract
Two types of combined multiphoton microscopy and optical coherence tomography (MPM/OCT) are compared for multimodal optical imaging. Single-scale multiphoton microscopy and optical coherence microscopy (MPM/OCM) is shown to acquire multiple contrasts from MPM and OCT simultaneously. Multi-scale MPM/OCT is shown to provide multiple field-of-views (FOVs), where OCT provides tissue level imaging and MPM provides cellular level imaging. In both types, the MPM includes two channels which are two-photon excited fluorescence (TPEF) and second harmonic generation (SHG). Representative images using each system are demonstrated on biological specimens. A detailed comparison of the two types of MPM/OCT shows that each system has its own pros and cons. MPM/OCM is high-resolution but with limited FOV, and OCM may or may not provide additional information than MPM depending on the samples. Multi-scale MPM/OCT can change FOV but need both low and high NA objectives. For future development, the two types of MPM/OCT can be further integrated to achieve both functions on a single system.
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Affiliation(s)
- Shuo Tang
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, Canada.
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Hong YJ, Makita S, Jaillon F, Ju MJ, Min EJ, Lee BH, Itoh M, Miura M, Yasuno Y. High-penetration swept source Doppler optical coherence angiography by fully numerical phase stabilization. Opt Express 2012; 20:2740-60. [PMID: 22330511 DOI: 10.1364/oe.20.002740] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
A high-penetration swept-source optical coherence tomography (HP-SS-OCT) system based on a 1-μm short cavity laser is developed. Doppler OCT processing is applied, along with a custom-made numerical phase stabilization algorithm; this process does not require additional calibration hardware. Thus, our phase stabilization method is simple and can be employed in a variety of SS-OCT systems. The bidirectional blood flow and vasculature in the deep choroid was successfully imaged via two Doppler modes that use different time intervals for Doppler processing. En face projection image of squared power of Doppler shift is compared to ICGA, and the utility of our method is verified.
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Affiliation(s)
- Young-Joo Hong
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
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Ju MJ, Lee SJ, Kim Y, Shin JG, Kim HY, Lim Y, Yasuno Y, Lee BH. Multimodal analysis of pearls and pearl treatments by using optical coherence tomography and fluorescence spectroscopy. Opt Express 2011; 19:6420-6432. [PMID: 21451670 DOI: 10.1364/oe.19.006420] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present an integrated optical system that consists of optical coherence tomography (OCT) and laser-induced fluorescence (LIF) spectroscopy for multimodal analysis of pearls and pearl treatments. The OCT source and the LIF excitation beams were aligned together to illuminate the same spot of a pearl fixed on the sample stage that was under rotation. As a result, both OCT images and LIF spectra of the pearls were detected at the same time and also at the same place. For OCT, a 1310 nm-centered swept laser source was used. For LIF, a 405 nm laser diode was used and a lensed multimode fiber was utilized as a fluorescence probe. The tomographic investigation on the internal structure of a pearl allowed us to evaluate and categorize the pearl nondestructively as was previously reported. In addition, the measurements of fluorescence spectrum and its decaying rate helped to determine the species of mother oyster. The proposed multimodal analysis made it possible to classify the pearls and also to disclose the treatments made on the pearls.
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Affiliation(s)
- Myeong Jin Ju
- School of Information and Mechatronics, GIST, Buk-gu, Gwangju, Korea
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Ju MJ, Lee SJ, Min EJ, Kim Y, Kim HY, Lee BH. Evaluating and identifying pearls and their nuclei by using optical coherence tomography. Opt Express 2010; 18:13468-13477. [PMID: 20588477 DOI: 10.1364/oe.18.013468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Optical coherence tomography (OCT) has been utilized to evaluate pearls including their nuclei noninvasively. By visualizing the internal structure of a pearl, we could measure the thickness of its nacre layer, observe the fine sub-structure of the nacre, and inspect the nucleus through the nacre. The system also allowed us to classify pearls into beaded- and non-beaded ones; usually, the saltwater ones have nuclei even though there are beaded freshwater pears and non-beaded saltwater pearls. Any cracks, crevices, or blemishes not only in the nacre but in the nucleus of a pearl could be clearly visualized. The OCT system was based on a 20 kHz swept-source of a 1.31microm central wavelength and an 110 nm full-width-at-half-maximum (FWHM) bandwidth. To get the 2-D images all around the circumference of a pearl, the pearl was rotated by a motorized rotating stage. And to achieve 3-D volume images, galvano-scans were made along two axes. Of all things, the OCT allowed us to check the use of a forbidden nucleus, usually made of a Giant Clam shell thus fragile, without hurting the pearl. With this modality, we believe, it would be possible evaluating pearls both in qualitative and quantitative. Comparison with the images taken with an optical microscope and X-ray radiograph gives the refractive index of pearl as about 1.53 in average.
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Affiliation(s)
- Myeong Jin Ju
- Department of Information and Communications, Gwanju, Korea
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Luo J, Ju MJ, Redies C. Regionalized cadherin-7 expression by radial glia is regulated by Shh and Pax7 during chicken spinal cord development. Neuroscience 2006; 142:1133-43. [PMID: 16973294 DOI: 10.1016/j.neuroscience.2006.07.038] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 07/17/2006] [Accepted: 07/17/2006] [Indexed: 10/24/2022]
Abstract
During development, several genes that specify neuronal subtype identity are expressed in distinct dorsoventral domains of the spinal cord and hindbrain. Cadherin-7 (Cad7), a member of the cadherin family of adhesion molecules, is expressed by radial glia in a dorsal domain of the spinal cord basal plate in chicken. To study the regulation of the Cad7 gene, we ectopically expressed two known dorsoventral patterning genes, Shh and Pax7, in the caudal neural tube and in two brain regions at different stages of development by in vivo electroporation. Results showed that Shh regulated the expression of Cad7 by radial glia in a concentration-dependent manner. Shh induced or repressed the expression of Cad7, at low and high concentrations, respectively. Furthermore, Pax7 inhibited the expression of Cad7. These results are compatible with a role of Shh and Pax7 in regulating endogenous Cad7 expression during spinal cord and hindbrain development. Our data show, for the first time, that Shh can regulate the expression not only of other gene regulatory factors, but also of Cad7, a morphoregulatory molecule that plays a role in axon elongation and neural circuit formation.
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Affiliation(s)
- J Luo
- Institute of Anatomy I, Friedrich Schiller University, Teichgraben 7, D-07740 Jena, Germany.
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Ju MJ, Aroca P, Luo J, Puelles L, Redies C. Molecular profiling indicates avian branchiomotor nuclei invade the hindbrain alar plate. Neuroscience 2005; 128:785-96. [PMID: 15464286 DOI: 10.1016/j.neuroscience.2004.06.063] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2004] [Indexed: 10/26/2022]
Abstract
It is generally believed that the spinal cord and hindbrain consist of a motor basal plate and a sensory alar plate. We now have molecular markers for these territories. The relationship of migrating branchiomotor neurons to molecularly defined alar and basal domains was examined in the chicken embryo by mapping the expression of cadherin-7 and cadherin-6B, in comparison to genetic markers for ventrodorsal patterning (Otp, Pax6, Pax7, Nkx2.2, and Shh) and motoneuron subpopulations (Phox2b and Isl1). We show cadherin-7 is expressed in a complete radial domain occupying a lateral region of the hindbrain basal plate. The cadherin-7 domain abuts the medial border of Pax7 expression; this common limit defines, or at least approximates, the basal/alar boundary. The hindbrain branchiomotor neurons originate in the medial part of the basal plate, close to the floor plate. Their cadherin-7-positive axons grow into the alar plate and exit the hindbrain close to the corresponding afferent nerve root. The cadherin-7-positive neuronal cell bodies later translocate laterally, following this axonal trajectory, thereby passing through the cadherin-7-positive basal plate domain. Finally, the cell bodies traverse the molecularly defined basal/alar boundary and move into positions within the alar plate. After the migration has ended, the branchiomotor neurons switch expression from cadherin-7 to cadherin-6B. These findings demonstrate that a specific subset of primary motor neurons, the branchiomotor neurons, migrate into the alar plate of the chicken embryo. Consequently, the century-old concept that all primary motor neurons come to reside in the basal plate should be revised.
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Affiliation(s)
- M J Ju
- Institute of Anatomy, University of Duisburg-Essen Medical School, D-45122 Essen, Germany
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