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Suh MH, Weinreb RN, Zangwill LM. Optic Disc Microvasculature Dropout in Preperimetric Glaucoma. J Glaucoma 2024; 33:490-498. [PMID: 38619387 DOI: 10.1097/ijg.0000000000002403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 02/29/2024] [Indexed: 04/16/2024]
Abstract
PRCIS Optic disc microvasculature dropout (MvD-D) was associated with worse disease severity in pre-perimetric glaucoma. MvD-D was not accompanied by focal lamina cribrosa defect or parapapillary deep-layer microvasculature dropout in 62.3% and 71.0% of eyes, respectively. PURPOSE To investigate factors associated with optic disc microvasculature dropout (MvD-D) in patients with preperimetric primary open angle glaucoma (PPG). METHODS One hundred thirty nine eyes of PPG patients were categorized according to the presence of MvD-D with optical coherence tomography angiography (OCTA). Factors including visual field (VF) mean deviation (MD), retinal nerve fiber layer (RNFL) thickness, focal lamina cribrosa (LC) defect, optic disc hemorrhage (DH), and parapapillary deep-layer microvasculature dropout (MvD-P) were compared between eyes with and without MvD-D. RESULTS MvD-D was observed in 69 PPG eyes (49.6%). Compared with eyes without MvD-D, the ones with MvD-D had a significantly thinner RNFL in all areas except the nasal sector, worse VF MD, and a focal LC defect and MvD-P ( P <0.05): male gender also was more highly prevalent. A considerable number of eyes with MvD-D lacked focal LC defect (62.3% [43/69]) or MvD-P (71.0% [49/69]), while a few eyes without MvD-D had focal LC defect (10.0% [7/70]) or MvD-P (2.9% [2/70]). In a multivariable logistic regression analysis, male gender (odds ratio [OR], 3.96; P <0.001), worse VF MD (OR, 1.44; P =0.019), thinner global RNFL (OR, 1.13; P <0.001), higher prevalence of focal LC defect (OR, 3.71; P =0.014) and MvD-P (OR, 7.85; P <0.001) were significantly associated with MvD-D. CONCLUSIONS MvD-D was related to worse disease severity in patients with PPG, and often was not accompanied by focal LC defect or MvD-P. This suggests that impaired optic disc circulation can be an early sign of glaucoma without noticeable changes in functional or structural features (i.e., VF, focal LC defect, MvD-P).
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Affiliation(s)
- Min Hee Suh
- Department of Ophthalmology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, South Korea
| | - Robert N Weinreb
- Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California San Diego, La Jolla, CA
| | - Linda M Zangwill
- Viterbi Family Department of Ophthalmology, Hamilton Glaucoma Center, Shiley Eye Institute, University of California San Diego, La Jolla, CA
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Abtahi M, Le D, Ebrahimi B, Dadzie AK, Rahimi M, Hsieh YT, Heiferman MJ, Lim JI, Yao X. Differential artery-vein analysis improves the OCTA classification of diabetic retinopathy. BIOMEDICAL OPTICS EXPRESS 2024; 15:3889-3899. [PMID: 38867785 PMCID: PMC11166441 DOI: 10.1364/boe.521657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/25/2024] [Accepted: 05/14/2024] [Indexed: 06/14/2024]
Abstract
This study investigates the impact of differential artery-vein (AV) analysis in optical coherence tomography angiography (OCTA) on machine learning classification of diabetic retinopathy (DR). Leveraging deep learning for arterial-venous area (AVA) segmentation, six quantitative features, including perfusion intensity density (PID), blood vessel density (BVD), vessel area flux (VAF), blood vessel caliber (BVC), blood vessel tortuosity (BVT), and vessel perimeter index (VPI) features, were derived from OCTA images before and after AV differentiation. A support vector machine (SVM) classifier was utilized to assess both binary and multiclass classifications of control, diabetic patients without DR (NoDR), mild DR, moderate DR, and severe DR groups. Initially, one-region features, i.e., quantitative features extracted from the entire OCTA, were evaluated for DR classification. Differential AV analysis improved classification accuracies from 78.86% to 87.63% and from 79.62% to 85.66% for binary and multiclass classifications, respectively. Additionally, three-region features derived from the entire image, parafovea, and perifovea, were incorporated for DR classification. Differential AV analysis further enhanced classification accuracies from 84.43% to 93.33% and from 83.40% to 89.25% for binary and multiclass classifications, respectively. These findings highlight the potential of differential AV analysis in augmenting disease diagnosis and treatment assessment using OCTA.
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Affiliation(s)
- Mansour Abtahi
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - David Le
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Behrouz Ebrahimi
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Albert K. Dadzie
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Mojtaba Rahimi
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Yi-Ting Hsieh
- Department of Ophthalmology, National Taiwan University Hospital, Taipei, Taiwan
| | - Michael J. Heiferman
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Jennifer I. Lim
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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3
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Hernandez RJ, Madhusudhan S, Zheng Y, El-Bouri WK. Linking Vascular Structure and Function: Image-Based Virtual Populations of the Retina. Invest Ophthalmol Vis Sci 2024; 65:40. [PMID: 38683566 PMCID: PMC11059806 DOI: 10.1167/iovs.65.4.40] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 04/02/2024] [Indexed: 05/01/2024] Open
Abstract
Purpose This study explored the relationship among microvascular parameters as delineated by optical coherence tomography angiography (OCTA) and retinal perfusion. Here, we introduce a versatile framework to examine the interplay between the retinal vascular structure and function by generating virtual vasculatures from central retinal vessels to macular capillaries. Also, we have developed a hemodynamics model that evaluates the associations between vascular morphology and retinal perfusion. Methods The generation of the vasculature is based on the distribution of four clinical parameters pertaining to the dimension and blood pressure of the central retinal vessels, constructive constrained optimization, and Voronoi diagrams. Arterial and venous trees are generated in the temporal retina and connected through three layers of capillaries at different depths in the macula. The correlations between total retinal blood flow and macular flow fraction and vascular morphology are derived as Spearman rank coefficients, and uncertainty from input parameters is quantified. Results A virtual cohort of 200 healthy vasculatures was generated. Means and standard deviations for retinal blood flow and macular flow fraction were 20.80 ± 7.86 µL/min and 15.04% ± 5.42%, respectively. Retinal blood flow was correlated with vessel area density, vessel diameter index, fractal dimension, and vessel caliber index. The macular flow fraction was not correlated with any morphological metrics. Conclusions The proposed framework is able to reproduce vascular networks in the macula that are morphologically and functionally similar to real vasculature. The framework provides quantitative insights into how macular perfusion can be affected by changes in vascular morphology delineated on OCTA.
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Affiliation(s)
- Rémi J. Hernandez
- Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart and Chest Hospital, Liverpool, United Kingdom
- Department of Cardiovascular and Metabolic Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Savita Madhusudhan
- St Paul's Eye Unit, Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom
- Department of Eye and Vision Sciences, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Yalin Zheng
- St Paul's Eye Unit, Liverpool University Hospitals NHS Foundation Trust, Liverpool, United Kingdom
- Department of Eye and Vision Sciences, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Wahbi K. El-Bouri
- Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart and Chest Hospital, Liverpool, United Kingdom
- Department of Cardiovascular and Metabolic Medicine, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
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Li M, Huang K, Xu Q, Yang J, Zhang Y, Ji Z, Xie K, Yuan S, Liu Q, Chen Q. OCTA-500: A retinal dataset for optical coherence tomography angiography study. Med Image Anal 2024; 93:103092. [PMID: 38325155 DOI: 10.1016/j.media.2024.103092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 11/10/2023] [Accepted: 01/22/2024] [Indexed: 02/09/2024]
Abstract
Optical coherence tomography angiography (OCTA) is a novel imaging modality that has been widely utilized in ophthalmology and neuroscience studies to observe retinal vessels and microvascular systems. However, publicly available OCTA datasets remain scarce. In this paper, we introduce the largest and most comprehensive OCTA dataset dubbed OCTA-500, which contains OCTA imaging under two fields of view (FOVs) from 500 subjects. The dataset provides rich images and annotations including two modalities (OCT/OCTA volumes), six types of projections, four types of text labels (age/gender/eye/disease) and seven types of segmentation labels (large vessel/capillary/artery/vein/2D FAZ/3D FAZ/retinal layers). Then, we propose a multi-object segmentation task called CAVF, which integrates capillary segmentation, artery segmentation, vein segmentation, and FAZ segmentation under a unified framework. In addition, we optimize the 3D-to-2D image projection network (IPN) to IPN-V2 to serve as one of the segmentation baselines. Experimental results demonstrate that IPN-V2 achieves an about 10% mIoU improvement over IPN on CAVF task. Finally, we further study the impact of several dataset characteristics: the training set size, the model input (OCT/OCTA, 3D volume/2D projection), the baseline networks, and the diseases. The dataset and code are publicly available at: https://ieee-dataport.org/open-access/octa-500.
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Affiliation(s)
- Mingchao Li
- School of Computer Science and Engineering, Nanjing University of Science and Technology, NanJing 210094, China.
| | - Kun Huang
- School of Computer Science and Engineering, Nanjing University of Science and Technology, NanJing 210094, China.
| | - Qiuzhuo Xu
- School of Computer Science and Engineering, Nanjing University of Science and Technology, NanJing 210094, China.
| | - Jiadong Yang
- School of Computer Science and Engineering, Nanjing University of Science and Technology, NanJing 210094, China.
| | - Yuhan Zhang
- School of Computer Science and Engineering, Nanjing University of Science and Technology, NanJing 210094, China.
| | - Zexuan Ji
- School of Computer Science and Engineering, Nanjing University of Science and Technology, NanJing 210094, China.
| | - Keren Xie
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, NanJing 210029, China.
| | - Songtao Yuan
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, NanJing 210029, China.
| | - Qinghuai Liu
- Department of Ophthalmology, The First Affiliated Hospital with Nanjing Medical University, NanJing 210029, China.
| | - Qiang Chen
- School of Computer Science and Engineering, Nanjing University of Science and Technology, NanJing 210094, China.
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Untracht GR, Durkee MS, Zhao M, Kwok-Cheung Lam A, Sikorski BL, Sarunic MV, Andersen PE, Sampson DD, Chen FK, Sampson DM. Towards standardising retinal OCT angiography image analysis with open-source toolbox OCTAVA. Sci Rep 2024; 14:5979. [PMID: 38472220 PMCID: PMC10933365 DOI: 10.1038/s41598-024-53501-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 02/01/2024] [Indexed: 03/14/2024] Open
Abstract
Quantitative assessment of retinal microvasculature in optical coherence tomography angiography (OCTA) images is important for studying, diagnosing, monitoring, and guiding the treatment of ocular and systemic diseases. However, the OCTA user community lacks universal and transparent image analysis tools that can be applied to images from a range of OCTA instruments and provide reliable and consistent microvascular metrics from diverse datasets. We present a retinal extension to the OCTA Vascular Analyser (OCTAVA) that addresses the challenges of providing robust, easy-to-use, and transparent analysis of retinal OCTA images. OCTAVA is a user-friendly, open-source toolbox that can analyse retinal OCTA images from various instruments. The toolbox delivers seven microvascular metrics for the whole image or subregions and six metrics characterising the foveal avascular zone. We validate OCTAVA using images collected by four commercial OCTA instruments demonstrating robust performance across datasets from different instruments acquired at different sites from different study cohorts. We show that OCTAVA delivers values for retinal microvascular metrics comparable to the literature and reduces their variation between studies compared to their commercial equivalents. By making OCTAVA publicly available, we aim to expand standardised research and thereby improve the reproducibility of quantitative analysis of retinal microvascular imaging. Such improvements will help to better identify more reliable and sensitive biomarkers of ocular and systemic diseases.
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Affiliation(s)
- Gavrielle R Untracht
- Department of Health Technology, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
- School of Biosciences, The University of Surrey, Guildford, GU27XH, UK
| | | | - Mei Zhao
- Centre for Myopia Research, School of Optometry, Faculty of Health and Social Science, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Andrew Kwok-Cheung Lam
- Centre for Myopia Research, School of Optometry, Faculty of Health and Social Science, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Bartosz L Sikorski
- Department of Ophthalmology, Nicolaus Copernicus University, 85-090, Bydgoszcz, Poland
- International Center for Translational Eye Research (ICTER), Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland
| | - Marinko V Sarunic
- Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E6BT, UK
- Institute of Ophthalmology, University College London, London, EC1V2PD, UK
| | - Peter E Andersen
- Department of Health Technology, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - David D Sampson
- School of Computer Science and Electronic Engineering, The University of Surrey, Guildford, GU27XH, UK
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), The University of Western Australia, Perth, WA, 6009, Australia
- Department of Ophthalmology, Royal Perth Hospital, Perth, WA, 6000, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, 3002, Australia
| | - Danuta M Sampson
- School of Biosciences, The University of Surrey, Guildford, GU27XH, UK.
- Institute of Ophthalmology, University College London, London, EC1V2PD, UK.
- Centre for Ophthalmology and Visual Science (Incorporating Lions Eye Institute), The University of Western Australia, Perth, WA, 6009, Australia.
- Department of Optometry, School of Allied Health, The University of Western Australia, Perth, WA, 6009, Australia.
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Al-Hinnawi AR, Al-Latayfeh M, Tavakoli M. Innovative Macula Capillaries Plexuses Visualization with OCTA B-Scan Graph Representation: Transforming OCTA B-Scan into OCTA Graph Representation. J Multidiscip Healthc 2023; 16:3477-3491. [PMID: 38024137 PMCID: PMC10662934 DOI: 10.2147/jmdh.s433405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/01/2023] [Indexed: 12/01/2023] Open
Abstract
Purpose The aim of this study is to transform optical coherence tomography angiography (OCTA) scans into innovative OCTA graphs, serving as novel biomarkers representing the macular vasculature. Patients and Methods The study included 90 healthy subjects and 39 subjects with various abnormalities (29 with diabetic retinopathy, 5 with age-related macular degeneration, and 5 with choroid neovascularization). OCTA 5µm macular coronal views (MCVs) were generated for each subject, followed by blood vessel segmentation and skeleton processing. Subsequently, the blood vessel density index, blood vessel skeleton index, and blood vessel tortuosity index were computed. The graphs of each metric were plotted against the axial axes of the OCTA B-scan, representing the integrity of vasculature at successive 5µm macular depths. Results The results revealed two significant findings. First, the B-scans from OCTA can be transformed into OCTA graphs, yielding three specific OCTA graphs in this study. These graphs provide new biomarkers for assessing the integrity of deep vascular complex (DVC) and superficial vascular complex (SVC) within the macula. Second, a statistically significant difference was observed between normal (n=90) and abnormal (n=39) subjects, with a t-test p-value significantly lower than 0.001. The Mann-Whitney u-test also yielded significant difference but only between the 90 normal and 29 DR subjects. Conclusion The novel OCTA graphs offer a unique representation of the macula's SVC and DVC, suggesting their potential in aiding physicians in the diagnosis of eye health within OCTA clinics. Further research is warranted to finalize the shape of these newly derived OCTA graphs and establish their clinical relevance and utility.
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Affiliation(s)
- Abdel-Razzak Al-Hinnawi
- Department of Medical Imaging, Faculty of Allied Medical Sciences, Isra University, Amman, Jordan
| | - Motasem Al-Latayfeh
- Department of Special Surgery, Faculty of Medicine, The Hashemite University, Zarqa, Jordan
| | - Mitra Tavakoli
- Exeter Centre of Excellence for Diabetes Research, National Institute for Health and Care Research (NIHR) Exeter Clinical Research Facility, and Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, Exeter, UK
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Le D, Dadzie A, Son T, Lim JI, Yao X. COMPARATIVE ANALYSIS OF OCT AND OCT ANGIOGRAPHY CHARACTERISTICS IN EARLY DIABETIC RETINOPATHY. Retina 2023; 43:992-998. [PMID: 36763982 PMCID: PMC10961166 DOI: 10.1097/iae.0000000000003761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
PURPOSE To assess the quantitative characteristics of optical coherence tomography (OCT) and OCT angiography (OCTA) for the objective detection of early diabetic retinopathy (DR). METHODS This was a retrospective and cross-sectional study, which was carried out at a tertiary academic practice with a subspecialty. Twenty control participants, 15 people with diabetics without retinopathy (NoDR), and 22 people with mild nonproliferative diabetic retinopathy (NPDR) were included in this study. Quantitative OCT characteristics were derived from the photoreceptor hyperreflective bands, i.e., inner segment ellipsoid (ISe) and retinal pigment epithelium (RPE). OCTA characteristics, including vessel diameter index (VDI), vessel perimeter index (VPI), and vessel skeleton density (VSD), were evaluated. RESULTS Quantitative OCT analysis indicated that the ISe intensity was significantly trending downward with DR advancement. Comparative OCTA revealed VDI, VPI, and VSD as the most sensitive characteristics of DR. Correlation analysis of OCT and OCTA characteristics revealed weak variable correlation between the two imaging modalities. CONCLUSION Quantitative OCT and OCTA analyses revealed photoreceptor and vascular distortions in early DR. Comparative analysis revealed that the OCT intensity ratio, ISe/RPE, has the best sensitivity for early DR detection. Weak variable correlation of the OCT and OCTA characteristics suggests that OCT and OCTA are providing supplementary information for DR detection and classification.
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Affiliation(s)
- David Le
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL; and
| | - Albert Dadzie
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL; and
| | - Taeyoon Son
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL; and
| | - Jennifer I Lim
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL; and
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL
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Abtahi M, Le D, Ebrahimi B, Dadzie AK, Lim JI, Yao X. An open-source deep learning network AVA-Net for arterial-venous area segmentation in optical coherence tomography angiography. COMMUNICATIONS MEDICINE 2023; 3:54. [PMID: 37069396 PMCID: PMC10110614 DOI: 10.1038/s43856-023-00287-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 04/06/2023] [Indexed: 04/19/2023] Open
Abstract
BACKGROUND Differential artery-vein (AV) analysis in optical coherence tomography angiography (OCTA) holds promise for the early detection of eye diseases. However, currently available methods for AV analysis are limited for binary processing of retinal vasculature in OCTA, without quantitative information of vascular perfusion intensity. This study is to develop and validate a method for quantitative AV analysis of vascular perfusion intensity. METHOD A deep learning network AVA-Net has been developed for automated AV area (AVA) segmentation in OCTA. Seven new OCTA features, including arterial area (AA), venous area (VA), AVA ratio (AVAR), total perfusion intensity density (T-PID), arterial PID (A-PID), venous PID (V-PID), and arterial-venous PID ratio (AV-PIDR), were extracted and tested for early detection of diabetic retinopathy (DR). Each of these seven features was evaluated for quantitative evaluation of OCTA images from healthy controls, diabetic patients without DR (NoDR), and mild DR. RESULTS It was observed that the area features, i.e., AA, VA and AVAR, can reveal significant differences between the control and mild DR. Vascular perfusion parameters, including T-PID and A-PID, can differentiate mild DR from control group. AV-PIDR can disclose significant differences among all three groups, i.e., control, NoDR, and mild DR. According to Bonferroni correction, the combination of A-PID and AV-PIDR can reveal significant differences in all three groups. CONCLUSIONS AVA-Net, which is available on GitHub for open access, enables quantitative AV analysis of AV area and vascular perfusion intensity. Comparative analysis revealed AV-PIDR as the most sensitive feature for OCTA detection of early DR. Ensemble AV feature analysis, e.g., the combination of A-PID and AV-PIDR, can further improve the performance for early DR assessment.
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Affiliation(s)
- Mansour Abtahi
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - David Le
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Behrouz Ebrahimi
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Albert K Dadzie
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Jennifer I Lim
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, 60607, USA.
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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Dadzie AK, Le D, Abtahi M, Ebrahimi B, Son T, Lim JI, Yao X. Normalized Blood Flow Index in Optical Coherence Tomography Angiography Provides a Sensitive Biomarker of Early Diabetic Retinopathy. Transl Vis Sci Technol 2023; 12:3. [PMID: 37017960 PMCID: PMC10082385 DOI: 10.1167/tvst.12.4.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/09/2023] [Indexed: 04/06/2023] Open
Abstract
Purpose To evaluate the sensitivity of normalized blood flow index (NBFI) for detecting early diabetic retinopathy (DR). Methods Optical coherence tomography angiography (OCTA) images of healthy controls, diabetic patients without DR (NoDR), and patients with mild nonproliferative DR (NPDR) were analyzed in this study. The OCTA images were centered on the fovea and covered a 6 mm × 6 mm area. Enface projections of the superficial vascular plexus (SVP) and the deep capillary plexus (DCP) were obtained for the quantitative OCTA feature analysis. Three quantitative OCTA features were examined: blood vessel density (BVD), blood flow flux (BFF), and NBFI. Each feature was calculated from both the SVP and DCP and their sensitivities to distinguish the three cohorts of the study were evaluated. Results The only quantitative feature capable of distinguishing all three cohorts was NBFI in the DCP image. Comparative study revealed that both BVD and BFF were able to distinguish the controls and NoDR from mild NPDR. However, neither BVD nor BFF was sensitive enough to separate NoDR from the healthy controls. Conclusions The NBFI has been demonstrated as a sensitive biomarker of early DR, revealing retinal blood flow abnormality better than traditional BVD and BFF. The NBFI in the DCP was verified as the most sensitive biomarker, supporting that diabetes affects the DCP earlier than SVP in DR. Translational Relevance NBFI provides a robust biomarker for quantitative analysis of DR-caused blood flow abnormalities, promising early detection and objective classification of DR.
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Affiliation(s)
- Albert K. Dadzie
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, USA
| | - David Le
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Mansour Abtahi
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Behrouz Ebrahimi
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Taeyoon Son
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Jennifer I. Lim
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
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Ma G, Son T, Adejumo T, Yao X. Rotational Distortion and Compensation in Optical Coherence Tomography with Anisotropic Pixel Resolution. Bioengineering (Basel) 2023; 10:313. [PMID: 36978706 PMCID: PMC10045376 DOI: 10.3390/bioengineering10030313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 02/24/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023] Open
Abstract
Accurate image registration is essential for eye movement compensation in optical coherence tomography (OCT) and OCT angiography (OCTA). The spatial resolution of an OCT instrument is typically anisotropic, i.e., has different resolutions in the lateral and axial dimensions. When OCT images have anisotropic pixel resolution, residual distortion (RD) and false translation (FT) are always observed after image registration for rotational movement. In this study, RD and FT were quantitively analyzed over different degrees of rotational movement and various lateral and axial pixel resolution ratio (RL/RA) values. The RD and FT provide the evaluation criteria for image registration. The theoretical analysis confirmed that the RD and FT increase significantly with the rotation degree and RL/RA. An image resizing assisting registration (RAR) strategy was proposed for accurate image registration. The performance of direct registration (DR) and RAR for retinal OCT and OCTA images were quantitatively compared. Experimental results confirmed that unnormalized RL/RA causes RD and FT; RAR can effectively improve the performance of OCT and OCTA image registration and distortion compensation.
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Affiliation(s)
- Guangying Ma
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL 60607, USA
| | - Taeyoon Son
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL 60607, USA
| | - Tobiloba Adejumo
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL 60607, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois Chicago, Chicago, IL 60612, USA
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Tsai WS, Thottarath S, Gurudas S, Pearce E, Giani A, Chong V, Gemmy Cheung CM, Sivaprasad S. Characterization of the Structural and Functional Alteration in Eyes with Diabetic Macular Ischemia. Ophthalmol Retina 2023; 7:142-152. [PMID: 35948210 DOI: 10.1016/j.oret.2022.07.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 07/11/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
OBJECTIVE To investigate the relative effect of disorganization of the retinal inner layers (DRIL) and ellipsoid zone (EZ) loss on visual function in diabetic macular ischemia (DMI). DESIGN Prospective cross-sectional observational study. PARTICIPANTS Patients with stable treated proliferative diabetic retinopathy (PDR) without center-involved diabetic macular edema were recruited at the Moorfields Eye Hospital from December 2019 to November 2021. The main inclusion criteria were best-corrected visual acuity (BCVA) of ≥ 40 ETDRS letters (Snellen equivalent 20/160) with OCT angiography (OCTA) evidence of DMI in ≥ 1 eye. METHODS Each eligible eye of the recruited patients was assessed for BCVA, OCT, and OCTA metrics. The prespecified OCT parameters were DRIL and subfoveal EZ loss. Generalized estimating equations were used. MAIN OUTCOMES MEASURES The frequency of DRIL and EZ loss, their relative contributions to vision loss, and their associations with microvascular alterations were evaluated. RESULTS A total of 125 eyes of 86 patients with PDR were enrolled; 104 (83%) eyes had a BCVA of ≥ 70 letters. Disorganization of the retinal inner layers was more prevalent than EZ loss (46% [58 eyes] vs. 19% [24 eyes]). On average, the presence of DRIL had a more pronounced impact on vision, retinal thickness, and microvascular parameters than EZ loss. After multivariable adjustment, the odds of coexisting DRIL increased by 12% with every letter decrease in BCVA; however, there was no statistically significant association of subfoveal EZ loss with BCVA. In eyes with DRIL in the absence of EZ loss, the BCVA declined significantly by 6.67 letters compared with eyes with no DRIL nor EZ loss (95% confidence interval [CI], -9.92 to -3.41; P < 0.001). However, if DRIL and EZ loss coexisted, the resultant BCVA was 13.22 letters less than eyes without these structural abnormalities (95% CI, -18.85 to -7.59; P < 0.001). CONCLUSIONS In patients with DMI with a Snellen visual acuity of 20/160 or better, eyes with DRIL were associated with more visual function loss and retinal blood circulation alterations than those with subfoveal EZ loss only.
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Affiliation(s)
- Wei-Shan Tsai
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; Institute of Ophthalmology, University College London, London, United Kingdom
| | - Sridevi Thottarath
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Sarega Gurudas
- Institute of Ophthalmology, University College London, London, United Kingdom
| | | | | | - Victor Chong
- Institute of Ophthalmology, University College London, London, United Kingdom
| | | | - Sobha Sivaprasad
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; Institute of Ophthalmology, University College London, London, United Kingdom.
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12
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Koctekin B, Karakus V, Dogan B, Erdem R, Dogan U, Buber H, Kurtoglu E. Optical coherence tomography angiography findings in transfusion-dependent beta-thalassemia patients with and without splenectomy. Photodiagnosis Photodyn Ther 2023; 42:103282. [PMID: 36639006 DOI: 10.1016/j.pdpdt.2023.103282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/31/2022] [Accepted: 01/06/2023] [Indexed: 01/12/2023]
Abstract
BACKGROUND Ocular involvement is common in transfusion-dependent beta-thalassemia (TDβ-T) patients. We aimed to investigate the effect of splenectomy on optical coherence tomography angiography (OCTA) findings in TDβ-T patients. METHODS The study is a prospective cross-sectional study. A total of 45 eyes of 23 patients with splenectomy (34.04±8.83 years), 18 eyes of 9 patients without splenectomy (27.44±5.43 years), and 54 eyes of 27 controls (33.22±6.44 years) were included. Vessel density in superficial capillary plexus, deep capillary plexus and radial peripapillary capillary, foveal avascular zone, choriocapillaris flow area, choroidal and retinal thickness detected by OCTA were evaluated. p < 0.05 was considered significant. RESULTS Vessel density of superficial capillary plexus and deep capillary plexus were similar in patients with and without splenectomy, and controls. Choriocapillaris flow area was significantly decreased in patients with splenectomy than that in those without splenectomy and controls (2.02±0.12 vs. 2.17±0.1 and 2.14±0.12; p < 0.001). Choroidal thickness was significantly lower in patients without splenectomy than in patients with splenectomy and controls (260.05±61.02 vs. 305.11±42.13 and 298.89±29.14, p = 0.008). Parafoveal and perifoveal thickness of the full retina and outer retina were significantly lower in patients without splenectomy than in patients with splenectomy and controls (301.06±10.0, 279.78±10.28 vs. 311.04±14.89, 290.87±13.67 and 316.63±13.57, 289.56±9.31, p < 0.001 and p = 0.002; 174.72±7.81, 167.17±6.21 vs. 182.87±8.81, 173.60±7.09 and 185.11±9.26, 173.96±6.79, p = 0.001 and p < 0.001, respectively). CONCLUSIONS OCTA findings can provide information about the microvascular effects of splenectomy on the retina of patients with TDβ-T.
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Affiliation(s)
- Belkis Koctekin
- Transfusion Center, Antalya Training and Research Hospital, University of Health Sciences, Antalya, Turkiye.
| | - Volkan Karakus
- Department of Hematology, Antalya Training and Research Hospital, University of Health Sciences, Antalya, Turkey
| | - Berna Dogan
- Department of Ophthalmology, Antalya Training and Research Hospital, University of Health Sciences, Antalya, Turkey
| | - Ramazan Erdem
- Department of Hematology, Antalya Training and Research Hospital, University of Health Sciences, Antalya, Turkey
| | - Ugur Dogan
- Department of General Surgery, Antalya Training and Research Hospital, University of Health Sciences, Antalya, Turkey
| | - Hakan Buber
- Department of Ophthalmology, Antalya Training and Research Hospital, University of Health Sciences, Antalya, Turkey
| | - Erdal Kurtoglu
- Department of Hematology, Kolan Hospital Group, Sisli Kolan International, Istanbul, Turkey
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13
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Mannil SS, Agarwal A, Conner IP, Kumar RS. A comprehensive update on the use of optical coherence tomography angiography in glaucoma. Int Ophthalmol 2022; 43:1785-1802. [PMID: 36472722 DOI: 10.1007/s10792-022-02574-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 11/12/2022] [Indexed: 12/12/2022]
Abstract
PURPOSE The primary purpose of this review is to provide a comprehensive summary on the technical principles of OCTA and to enumerate vascular parameters being explicated for glaucoma diagnosis and progression with emphasis on recent studies. In addition, the authors also summarize the future clinical potentials of OCTA in glaucoma and enumerate the limitations of this imaging modality in the present-day scenario. METHODS The index study is a narrative review on OCTA in glaucoma. The authors searched the PubMed database using the key phrases ''optical coherence tomography angiography" AND "glaucoma,'' AND/OR "vascular parameters" AND/OR "ocular perfusion." Being a relatively recent development in ocular imaging, studies in which OCTA imaging had been used for glaucoma evaluation since 2012 were included until March 2022. The literature search included original studies and previous review articles, while case reports were excluded. Preliminary search was based on relevant articles with search keywords in the title and abstract. The second screening was performed by reading the full text of the literature. RESULTS Recent studies indicate reduction in microcirculation in glaucomatous eyes compared to the normal subjects. The area of interest for glaucoma evaluation using OCTA varies among the different studies. Based on the literature reviewed here, (1) OCTA parameters measured in the peripapillary; ONH and macular area have been shown to differentiate between glaucoma and normal eyes with a discriminatory power comparable to OCT parameters used routinely in clinics, (2) monitoring of peripapillary and macular vessel density may provide important information to the evaluation of glaucoma progression and prediction of rates of disease worsening, (3) studies suggest strong correlation between the OCTA parameters, the OCT parameters and visual function, measured by visual field testing, in glaucomatous eyes, (4) future prospects of OCTA in glaucoma evaluations using AI predicting structural and functional features and prognosis based on early vascular findings would open up scope for early detection of high-risk suspects and fast progressors in glaucoma. CONCLUSION OCTA can be useful in quantifying vascular parameters in the optic disc, peripapillary and the macular regions for glaucoma evaluation. OCTA shows potential to become a part of everyday glaucoma management.
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Affiliation(s)
- Suria S Mannil
- Byers Eye Institute, Stanford University, Palo Alto, USA
| | - Aniruddha Agarwal
- Cleveland Clinic Abu Dhabi, The Eye Institute, Al Maryah Island, 112412, Abu Dhabi, United Arab Emirates
- Cleveland Clinic Lerner College of Medicine, Case Western, Reserve University, Cleveland, OH, USA
| | - Ian P Conner
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, USA
| | - Rajesh S Kumar
- Cleveland Clinic Abu Dhabi, The Eye Institute, Al Maryah Island, 112412, Abu Dhabi, United Arab Emirates.
- Cleveland Clinic Lerner College of Medicine, Case Western, Reserve University, Cleveland, OH, USA.
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14
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Huseyinhan Z, Ozcaliskan S, Gurez C, Artunay O. Retinal and choroidal microvasculature is altered after strabismus surgery. Eur J Ophthalmol 2022; 33:11206721221137156. [PMID: 36325688 DOI: 10.1177/11206721221137156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
PURPOSE To evaluate the retinal and choroidal microvasculature after strabismus surgery using swept-source optical coherence tomography angiography (OCTA). METHODS Thirty-three eyes of 33 patients who underwent horizontal rectus surgery for strabismus were included in this retrospective study. The unoperated fellow eyes were used as the control group. The macular microvasculature was assessed using a 3 × 3 scan pattern centred on the fovea preoperatively, and one week and one month postoperatively. The vessel density (VD) of superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) were automatically analyzed. The foveal avascular zone (FAZ) was calculated manually using the tool of the device. RESULTS The VD in SCP demonstrated a significant difference between operated and fellow eyes at one week (p = 0.017). Moreover, a significant increase was observed in the mean VD values in SCP of operated eyes after surgery (p = 0.037). The VD in DCP exhibited no significant differences between operated and fellow eyes before and after strabismus surgery. However, there was a significant difference in VD was observed between operated and fellow eyes one week after surgery (p = 0.001). The mean VD in CC was significantly increased in the operated eyes one week after surgery compared to preoperative values (p = 0.006). CONCLUSION This study revealed that strabismus surgery may cause transient alterations both in retinal and choroidal microcirculation in the early postoperative period.
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Affiliation(s)
- Zahid Huseyinhan
- 147017Beyoğlu Eye Training and Research Hospital, 448249University of Health Sciences, Istanbul, Turkey
| | - Sehnaz Ozcaliskan
- 147017Beyoğlu Eye Training and Research Hospital, 448249University of Health Sciences, Istanbul, Turkey
| | - Ceren Gurez
- 147017Beyoğlu Eye Training and Research Hospital, 448249University of Health Sciences, Istanbul, Turkey
| | - Ozgur Artunay
- 147017Beyoğlu Eye Training and Research Hospital, 448249University of Health Sciences, Istanbul, Turkey
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15
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Ke W, Yu N, Liu X, Gu Y, Qin Q, Ye Z, Li Y, Wang K, Chen M. Analysis of macular microvasculature with optical coherence tomography angiography for migraine: A systematic review and meta-analysis. Front Neurol 2022; 13:1001304. [PMID: 36313505 PMCID: PMC9606770 DOI: 10.3389/fneur.2022.1001304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 09/26/2022] [Indexed: 11/26/2022] Open
Abstract
Objective This study aimed to evaluate the features of macular microvasculature with optical coherence tomography angiography (OCTA) among migraine patients. Methods We systematically searched PubMed, Web of Science, Embase, and Cochrane Library for studies that evaluated the macular microvasculature of migraine patients. The weighted mean differences (WMDs) of the foveal avascular zone (FAZ), foveal superficial capillary plexus (SCP) vessel density (VD), parafoveal SCP VD, foveal deep capillary plexus (DCP) VD, and parafoveal DCP VD with 95% confidence intervals (CIs) among migraine with aura (MA) group, migraine without aura (MO) group, and healthy controls (HC) group were analyzed using a random-effect model. P < 0.05 was considered significant in statistical analyses. Publication bias was assessed using funnel plots and statistical tests (Egger's test and Begg's test). Results Nine studies covering 675 individuals were enrolled in this meta-analysis ultimately. The FAZ of MA patients was not significantly different from HC (WMD = 0.04, 95% CI −0.00 to 0.09). However, the FAZ of MA was significantly larger than that of HC after correction of publication bias by trim and fill method (WMD = 1.03, 95% CI 0.99 to 1.08). The FAZ of MO patients was similar to that of HC (WMD = 0.03, 95% CI −0.00 to 0.07), while smaller than that of MA patients (WMD = 0.05, 95% CI 0.01 to 0.09). VD of the SCP, either in the foveal or parafoveal area, was not significantly different among the three groups. As for DCP, VD in MA patients was lower when compared with HC in the parafovea (WMD = −1.20, 95% CI −1.88 to −0.51). Conclusions We found that there was a larger FAZ in MA compared with HC after adjusting for publication bias. The FAZ in MO was not significantly different from that in HC, but significantly lower than that in MA. There was no significant difference in either foveal or parafoveal VD of SCP among MA, MO, and HC participants, while the parafoveal VD of the DCP in MA was lower than that of the HC.
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Affiliation(s)
- Weishaer Ke
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, China
| | - Naiji Yu
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, China
| | - Xin Liu
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, China
| | - Yuxiang Gu
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, China
| | - Qiyu Qin
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, China
| | - Zifan Ye
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, China
| | - Yuhang Li
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, China
| | - Kaijun Wang
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, China
- *Correspondence: Kaijun Wang
| | - Min Chen
- Eye Center of the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Zhejiang Provincial Key Laboratory of Ophthalmology, Hangzhou, China
- Min Chen
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Abtahi M, Le D, Lim JI, Yao X. MF-AV-Net: an open-source deep learning network with multimodal fusion options for artery-vein segmentation in OCT angiography. BIOMEDICAL OPTICS EXPRESS 2022; 13:4870-4888. [PMID: 36187235 PMCID: PMC9484445 DOI: 10.1364/boe.468483] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/12/2022] [Accepted: 08/12/2022] [Indexed: 06/16/2023]
Abstract
This study is to demonstrate the effect of multimodal fusion on the performance of deep learning artery-vein (AV) segmentation in optical coherence tomography (OCT) and OCT angiography (OCTA); and to explore OCT/OCTA characteristics used in the deep learning AV segmentation. We quantitatively evaluated multimodal architectures with early and late OCT-OCTA fusions, compared to the unimodal architectures with OCT-only and OCTA-only inputs. The OCTA-only architecture, early OCT-OCTA fusion architecture, and late OCT-OCTA fusion architecture yielded competitive performances. For the 6 mm×6 mm and 3 mm×3 mm datasets, the late fusion architecture achieved an overall accuracy of 96.02% and 94.00%, slightly better than the OCTA-only architecture which achieved an overall accuracy of 95.76% and 93.79%. 6 mm×6 mm OCTA images show AV information at pre-capillary level structure, while 3 mm×3 mm OCTA images reveal AV information at capillary level detail. In order to interpret the deep learning performance, saliency maps were produced to identify OCT/OCTA image characteristics for AV segmentation. Comparative OCT and OCTA saliency maps support the capillary-free zone as one of the possible features for AV segmentation in OCTA. The deep learning network MF-AV-Net used in this study is available on GitHub for open access.
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Affiliation(s)
- Mansour Abtahi
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- These authors contributed equally to this work
| | - David Le
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- These authors contributed equally to this work
| | - Jennifer I. Lim
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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Gurevich IB, Yashina VV, Tleubaev AT. Research and Development of the Method for Automating the Diagnostic Analysis of Human Fundus Images Produced by Optical Coherent Tomography Angiography. PATTERN RECOGNITION AND IMAGE ANALYSIS 2022. [DOI: 10.1134/s1054661822030154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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18
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Li Y, Zheng F, Foo LL, Wong QY, Ting D, Hoang QV, Chong R, Ang M, Wong CW. Advances in OCT Imaging in Myopia and Pathologic Myopia. Diagnostics (Basel) 2022; 12:diagnostics12061418. [PMID: 35741230 PMCID: PMC9221645 DOI: 10.3390/diagnostics12061418] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 06/06/2022] [Accepted: 06/06/2022] [Indexed: 11/16/2022] Open
Abstract
Advances in imaging with optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) technology, including the development of swept source OCT/OCTA, widefield or ultra-widefield systems, have greatly improved the understanding, diagnosis, and treatment of myopia and myopia-related complications. Anterior segment OCT is useful for imaging the anterior segment of myopes, providing the basis for implantable collamer lens optimization, or detecting intraocular lens decentration in high myopic patients. OCT has enhanced imaging of vitreous properties, and measurement of choroidal thickness in myopic eyes. Widefield OCT systems have greatly improved the visualization of peripheral retinal lesions and have enabled the evaluation of wide staphyloma and ocular curvature. Based on OCT imaging, a new classification system and guidelines for the management of myopic traction maculopathy have been proposed; different dome-shaped macula morphologies have been described; and myopia-related abnormalities in the optic nerve and peripapillary region have been demonstrated. OCTA can quantitatively evaluate the retinal microvasculature and choriocapillaris, which is useful for the early detection of myopic choroidal neovascularization and the evaluation of anti-vascular endothelial growth factor therapy in these patients. In addition, the application of artificial intelligence in OCT/OCTA imaging in myopia has achieved promising results.
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Affiliation(s)
- Yong Li
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.L.); (F.Z.); (L.L.F.); (Q.Y.W.); (D.T.); (Q.V.H.); (R.C.); (M.A.)
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Feihui Zheng
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.L.); (F.Z.); (L.L.F.); (Q.Y.W.); (D.T.); (Q.V.H.); (R.C.); (M.A.)
| | - Li Lian Foo
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.L.); (F.Z.); (L.L.F.); (Q.Y.W.); (D.T.); (Q.V.H.); (R.C.); (M.A.)
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Qiu Ying Wong
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.L.); (F.Z.); (L.L.F.); (Q.Y.W.); (D.T.); (Q.V.H.); (R.C.); (M.A.)
| | - Daniel Ting
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.L.); (F.Z.); (L.L.F.); (Q.Y.W.); (D.T.); (Q.V.H.); (R.C.); (M.A.)
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Quan V. Hoang
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.L.); (F.Z.); (L.L.F.); (Q.Y.W.); (D.T.); (Q.V.H.); (R.C.); (M.A.)
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
- Department of Ophthalmology, Columbia University, New York, NY 10027, USA
| | - Rachel Chong
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.L.); (F.Z.); (L.L.F.); (Q.Y.W.); (D.T.); (Q.V.H.); (R.C.); (M.A.)
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Marcus Ang
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.L.); (F.Z.); (L.L.F.); (Q.Y.W.); (D.T.); (Q.V.H.); (R.C.); (M.A.)
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
| | - Chee Wai Wong
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore 169856, Singapore; (Y.L.); (F.Z.); (L.L.F.); (Q.Y.W.); (D.T.); (Q.V.H.); (R.C.); (M.A.)
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore 169857, Singapore
- Correspondence:
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Tsai WS, Thottarath S, Gurudas S, Sen P, Pearce E, Giani A, Chong V, Cheung CMG, Sivaprasad S. Correlation of Optical Coherence Tomography Angiography Characteristics with Visual Function to Define Vision-Threatening Diabetic Macular Ischemia. Diagnostics (Basel) 2022; 12:diagnostics12051050. [PMID: 35626206 PMCID: PMC9139901 DOI: 10.3390/diagnostics12051050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 04/15/2022] [Accepted: 04/20/2022] [Indexed: 12/10/2022] Open
Abstract
The thresholds of macular microvasculature parameters associated with mild visual impairment in diabetic macular ischemia (DMI) patients are unclear. Therefore, this prospective observational study is aimed at demonstrating the optical coherence tomography angiography parameters that best correlate with mild visual impairment (<70 Early Treatment Diabetic Retinopathy Study (ETDRS) letters, Snellen equivalent 20/40) in DMI. The study was completed at the Moorfields Eye Hospital from December 2019 to August 2021. A total of 123 eyes of 87 patients with stable-treated proliferative diabetic retinopathy following panretinal photocoagulation were recruited. DMI was defined as an irregular foveal avascular zone (FAZ) area ≥ 0.5 mm2 or a smaller FAZ area with parafoveal capillary dropout in at least one quadrant. The analysis showed that the whole image deep vascular complex vessel density (DVC VD) in the 3 × 3 mm area had the best discriminatory ability to identify participants with mild visual impairment at 41.9% (area under the curve = 0.77, sensitivity 94%, specificity 54%, likelihood ratio [LR] = 2.04), and the FAZ area had the greatest post-test LR = 4.21 at 0.64 mm2. The 3 × 3 mm whole image DVC VD and FAZ area cutoffs are useful for screening vision-threatening DMI, but DVC VD has low specificity.
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Affiliation(s)
- Wei-Shan Tsai
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London EC1V 2PD, UK; (W.-S.T.); (S.T.)
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK; (S.G.); (P.S.); (V.C.)
| | - Sridevi Thottarath
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London EC1V 2PD, UK; (W.-S.T.); (S.T.)
| | - Sarega Gurudas
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK; (S.G.); (P.S.); (V.C.)
| | - Piyali Sen
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK; (S.G.); (P.S.); (V.C.)
| | - Elizabeth Pearce
- Boehringer Ingelheim, Binger Street 173, 55218 Ingelheim am Rhein, Germany; (E.P.); (A.G.)
| | - Andrea Giani
- Boehringer Ingelheim, Binger Street 173, 55218 Ingelheim am Rhein, Germany; (E.P.); (A.G.)
| | - Victor Chong
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK; (S.G.); (P.S.); (V.C.)
| | | | - Sobha Sivaprasad
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, 162 City Road, London EC1V 2PD, UK; (W.-S.T.); (S.T.)
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK; (S.G.); (P.S.); (V.C.)
- Correspondence: ; Tel.: +44-7817-886759
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Kim TH, Ma G, Son T, Yao X. Functional Optical Coherence Tomography for Intrinsic Signal Optoretinography: Recent Developments and Deployment Challenges. Front Med (Lausanne) 2022; 9:864824. [PMID: 35445037 PMCID: PMC9013890 DOI: 10.3389/fmed.2022.864824] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/16/2022] [Indexed: 11/13/2022] Open
Abstract
Intrinsic optical signal (IOS) imaging of the retina, also termed as optoretinogram or optoretinography (ORG), promises a non-invasive method for the objective assessment of retinal function. By providing the unparalleled capability to differentiate individual retinal layers, functional optical coherence tomography (OCT) has been actively investigated for intrinsic signal ORG measurements. However, clinical deployment of functional OCT for quantitative ORG is still challenging due to the lack of a standardized imaging protocol and the complication of IOS sources and mechanisms. This article aims to summarize recent developments of functional OCT for ORG measurement, OCT intensity- and phase-based IOS processing. Technical challenges and perspectives of quantitative IOS analysis and ORG interpretations are discussed.
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Affiliation(s)
- Tae-Hoon Kim
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Guangying Ma
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Taeyoon Son
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
| | - Xincheng Yao
- Richard and Loan Hill Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL, United States
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, United States
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21
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Sampson DM, Dubis AM, Chen FK, Zawadzki RJ, Sampson DD. Towards standardizing retinal optical coherence tomography angiography: a review. LIGHT, SCIENCE & APPLICATIONS 2022; 11:63. [PMID: 35304441 PMCID: PMC8933532 DOI: 10.1038/s41377-022-00740-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 02/01/2022] [Accepted: 02/14/2022] [Indexed: 05/11/2023]
Abstract
The visualization and assessment of retinal microvasculature are important in the study, diagnosis, monitoring, and guidance of treatment of ocular and systemic diseases. With the introduction of optical coherence tomography angiography (OCTA), it has become possible to visualize the retinal microvasculature volumetrically and without a contrast agent. Many lab-based and commercial clinical instruments, imaging protocols and data analysis methods and metrics, have been applied, often inconsistently, resulting in a confusing picture that represents a major barrier to progress in applying OCTA to reduce the burden of disease. Open data and software sharing, and cross-comparison and pooling of data from different studies are rare. These inabilities have impeded building the large databases of annotated OCTA images of healthy and diseased retinas that are necessary to study and define characteristics of specific conditions. This paper addresses the steps needed to standardize OCTA imaging of the human retina to address these limitations. Through review of the OCTA literature, we identify issues and inconsistencies and propose minimum standards for imaging protocols, data analysis methods, metrics, reporting of findings, and clinical practice and, where this is not possible, we identify areas that require further investigation. We hope that this paper will encourage the unification of imaging protocols in OCTA, promote transparency in the process of data collection, analysis, and reporting, and facilitate increasing the impact of OCTA on retinal healthcare delivery and life science investigations.
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Affiliation(s)
- Danuta M Sampson
- Surrey Biophotonics, Centre for Vision, Speech and Signal Processing and School of Biosciences and Medicine, The University of Surrey, Guildford, GU2 7XH, UK.
| | - Adam M Dubis
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Trust and UCL Institute of Ophthalmology, London, EC1V 2PD, UK
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Nedlands, Western Australia, 6009, Australia
- Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, 6000, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Victoria, 3002, Australia
| | - Robert J Zawadzki
- Department of Ophthalmology & Vision Science, University of California Davis, Sacramento, CA, 95817, USA
| | - David D Sampson
- Surrey Biophotonics, Advanced Technology Institute, School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, Surrey, GU2 7XH, UK
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22
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Retinal Vessel Density in Age-Related Macular Degeneration Patients with Geographic Atrophy. J Clin Med 2022; 11:jcm11061501. [PMID: 35329825 PMCID: PMC8949909 DOI: 10.3390/jcm11061501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/26/2022] [Accepted: 03/07/2022] [Indexed: 11/17/2022] Open
Abstract
We compared the retinal vessel density and inner retinal thickness in patients who had one eye with geographic atrophy (GA) and a fellow eye with intermediate age-related macular degeneration (iAMD). The vessel density from the superficial vascular complex (SVC) and deep vascular complex (DVC) through optical coherence tomography angiography and the thickness of the nerve fiber layer, ganglion cell-inner plexiform layer (GCIPL), inner nuclear layer (INL), outer nuclear layer (ONL) on a structural optical coherence tomography thickness map were measured in 28 eyes of 14 GA patients with iAMD in the fellow eye. GA eyes had significantly lower vessel density in the SVC (26.2 ± 3.9% vs. 28.3 ± 4.4%; p = 0.015) and DVC (24.2 ± 2.6% vs. 26.8 ± 1.9%; p = 0.003) than fellow eyes (iAMD). GCIPL and ONL were significantly thinner in GA eyes than in the fellow eyes (p = 0.032 and 0.024 in the foveal areas, p = 0.029 and 0.065 in the parafovea areas, respectively). Twenty-four eyes of 12 patients were followed up for 2 years and seven of the fellow eyes (58.3%) developed GA during the follow-up period and showed reduced vessel density in the SVC (26.4 ± 3.0% vs. 23.8 ± 2.9%; p = 0.087) and DVC (25.8 ± 2.2% vs. 22.4 ± 4.4%; p = 0.047) compared to baseline. Vessel density and GCIPL thickness map measurements are potential GA markers in non-neovascular AMD.
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Abstract
PURPOSE OF REVIEW To summarize the literature on three-dimensional (3D) technological advances in ophthalmology, the quantitative methods associated with this, and their improved ability to help detect glaucoma disease progression. RECENT FINDINGS Improvements in measuring glaucomatous structural changes are the result of dual innovations in optical coherence tomography (OCT) imaging technology and in associated quantitative software. SUMMARY Compared with two-dimensional (2D) OCT parameters, newer 3D parameters provide more data and fewer artifacts.
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Affiliation(s)
- Maria A. Guzman Aparicio
- Harvard Medical School
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Glaucoma Service, Boston, Massachusetts, USA
| | - Teresa C. Chen
- Harvard Medical School
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Glaucoma Service, Boston, Massachusetts, USA
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24
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Role of Anterior Segment-Optical Coherence Tomography Angiography in Acute Ocular Burns. Diagnostics (Basel) 2022; 12:diagnostics12030607. [PMID: 35328160 PMCID: PMC8947509 DOI: 10.3390/diagnostics12030607] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/09/2022] [Accepted: 02/21/2022] [Indexed: 02/01/2023] Open
Abstract
Acute ocular burns have varied manifestations which require prompt diagnosis and management to prevent chronic sequelae. Of these, the detection of limbal ischemia poses a challenge because of the subjective nature of its clinical signs. Anterior segment optical coherence tomography angiography (AS-OCTA) offers an objective method of assessing ischemia in these eyes. This review provides an overview of the technology of AS-OCTA and its applications in acute burns. AS-OCTA generates images by isolating the movement of erythrocytes within blood vessels from sequentially obtained b-scans. Limbal ischemia manifests in these scans as absent vasculature and the extent of ischemia can be quantified using different vessel-related parameters. Of these, the density of vessels is most commonly used and correlates with the severity of the injury. Incorporation of the degree of ischemia in the classification of acute burns has been attempted in animal studies and its extension to human trials may provide an added dimension in determining the final prognosis of these eyes. Thus, AS-OCTA is a promising device that can objectively evaluate limbal ischemia. This will facilitate the identification of patients who will benefit from revascularization therapies and stem cell transplants in acute and chronic ocular burns, respectively.
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25
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Thangamathesvaran L, Ong SS, Wang J, Lance E, Tekes A, Scott AW. EVALUATION OF MACULAR FLOW VOIDS ON OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY AS POTENTIAL BIOMARKERS FOR SILENT CEREBRAL INFARCTION IN SICKLE CELL DISEASE. Retina 2022; 42:340-347. [PMID: 34608107 DOI: 10.1097/iae.0000000000003309] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the relationship between macular microvascular abnormalities on optical coherence tomography angiography and silent cerebral infarctions (SCIs) on cerebral magnetic resonance imaging in sickle cell disease. METHODS Patients (age <18 years old) from our previous pediatric sickle cell disease study cohort who had prior optical coherence tomography angiography and brain magnetic resonance imaging were identified. Brain magnetic resonance imaging images were compared with macular optical coherence tomography angiography scans to identify macular vascular density differences between patients with SCI and without SCI. RESULTS Sixty-eight eyes from 34 patients who underwent optical coherence tomography angiography were evaluated, of whom 28 eyes from 14 patients met the inclusion criteria for this study. Eight patients (57%) with SCI and 6 patients (43%) without SCI were identified. The mean age (17 years in SCI and 16.3 years in non-SCI) was comparable between groups. There was no statistically significant difference in systemic complications. Deep capillary plexus vessel density was lower in the temporal quadrant in patients with SCI (49.3% vs. 53.7%, P = 0.014). CONCLUSION Patients with SCI were found to have lower vessel density in the deep capillary plexus compared with those without SCI. This finding suggests that deep capillary plexus vessel density may have utility as an imaging biomarker to predict the presence of SCI.
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Affiliation(s)
- Loka Thangamathesvaran
- Retina Division, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Sally S Ong
- Department of Ophthalmology and Visual Science, Wake Forest Baptist Health, Winston-Salem, North Carolina
| | - Jiangxia Wang
- Department of Biostatistics, Wilmer Biostats Center, Johns Hopkins University, Baltimore, Maryland
| | - Eboni Lance
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland; and
| | - Aylin Tekes
- Department of Pediatric Radiology and Pediatric Neuroradiology, Russell Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Adrienne W Scott
- Retina Division, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
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26
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Adejumo T, Kim TH, Le D, Son T, Ma G, Yao X. Depth-resolved vascular profile features for artery-vein classification in OCT and OCT angiography of human retina. BIOMEDICAL OPTICS EXPRESS 2022; 13:1121-1130. [PMID: 35284164 PMCID: PMC8884205 DOI: 10.1364/boe.450913] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/22/2022] [Accepted: 01/23/2022] [Indexed: 05/11/2023]
Abstract
This study is to characterize reflectance profiles of retinal blood vessels in optical coherence tomography (OCT), and to test the potential of using these vascular features to guide artery-vein classification in OCT angiography (OCTA) of the human retina. Depth-resolved OCT reveals unique features of retinal arteries and veins. Retinal arteries show hyper-reflective boundaries at both upper (inner side towards the vitreous) and lower (outer side towards the choroid) walls. In contrast, retinal veins reveal hyper-reflectivity at the upper boundary only. Uniform lumen intensity was observed in both small and large arteries. However, the venous lumen intensity was dependent on the vessel size. Small veins exhibit a hyper-reflective zone at the bottom half of the lumen, while large veins show a hypo-reflective zone at the bottom half of the lumen.
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Affiliation(s)
- Tobiloba Adejumo
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- These authors contributed equally to this work
| | - Tae-Hoon Kim
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- These authors contributed equally to this work
| | - David Le
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Taeyoon Son
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Guangying Ma
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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27
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Bouma B, de Boer J, Huang D, Jang I, Yonetsu T, Leggett C, Leitgeb R, Sampson D, Suter M, Vakoc B, Villiger M, Wojtkowski M. Optical coherence tomography. NATURE REVIEWS. METHODS PRIMERS 2022; 2:79. [PMID: 36751306 PMCID: PMC9901537 DOI: 10.1038/s43586-022-00162-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Optical coherence tomography (OCT) is a non-contact method for imaging the topological and internal microstructure of samples in three dimensions. OCT can be configured as a conventional microscope, as an ophthalmic scanner, or using endoscopes and small diameter catheters for accessing internal biological organs. In this Primer, we describe the principles underpinning the different instrument configurations that are tailored to distinct imaging applications and explain the origin of signal, based on light scattering and propagation. Although OCT has been used for imaging inanimate objects, we focus our discussion on biological and medical imaging. We examine the signal processing methods and algorithms that make OCT exquisitely sensitive to reflections as weak as just a few photons and that reveal functional information in addition to structure. Image processing, display and interpretation, which are all critical for effective biomedical imaging, are discussed in the context of specific applications. Finally, we consider image artifacts and limitations that commonly arise and reflect on future advances and opportunities.
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Affiliation(s)
- B.E. Bouma
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA,Institute for Medical Engineering and Physics, Massachusetts Institute of Technology, Cambridge, MA, USA,Harvard Medical School, Boston, MA, USA,Corresponding author:
| | - J.F. de Boer
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - D. Huang
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, USA
| | - I.K. Jang
- Harvard Medical School, Boston, MA, USA,Cardiology Division, Massachusetts General Hospital, Boston, MA, USA
| | - T. Yonetsu
- Department of Cardiovascular Medicine, Tokyo Medical and Dental University
| | - C.L. Leggett
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA
| | - R. Leitgeb
- Institute of Medical Physics, University of Vienna, Wien, Austria
| | - D.D. Sampson
- School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, United Kingdom
| | - M. Suter
- Harvard Medical School, Boston, MA, USA,Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - B. Vakoc
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA,Harvard Medical School, Boston, MA, USA
| | - M. Villiger
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA,Harvard Medical School, Boston, MA, USA
| | - M. Wojtkowski
- Institute of Physical Chemistry and International Center for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland,Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun, Poland
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28
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Ripolles-Garcia A, Ruthel G, Ying GS, Chen Y, Cuenca N, Aguirre GD, Beltran WA. Characterization of the Canine Retinal Vasculature With Optical Coherence Tomography Angiography: Comparisons With Histology and Fluorescein Angiography. Front Neuroanat 2021; 15:785249. [PMID: 34966262 PMCID: PMC8710516 DOI: 10.3389/fnana.2021.785249] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 11/23/2021] [Indexed: 11/16/2022] Open
Abstract
Purpose: To present a methodology for quantification of the canine retinal vasculature imaged by optical coherence tomography angiography (OCTA) and validate this approach by comparison with fluorescein angiography (FA) and confocal imaging of retinal wholemounts labelled by immunohistochemistry (IHC). Methods: Six normal adult dogs underwent retinal OCTA imaging in both eyes. The images extracted from the different microvascular plexuses at eight retinal locations spanning the central and mid-peripheral fundus were analyzed using the AngioTool software. FA was performed in one eye and was compared to the OCTA images. Six eyes from three dogs were processed by IHC to examine the retinal vasculature. Results: A total of four retinal plexuses were identified by OCTA in the canine retina, and their density and topographical pattern varied with eccentricity. OCTA offered improved resolution over FA with the advantage of allowing imaging of the individual plexuses. Detection by OCTA of small vessels within the deep capillary plexus was possible and approached the level of resolution achieved with ex vivo imaging of the retinal vasculature by confocal microscopy/IHC. The plexuses herein described are analogous to human retinal vasculature. Conclusion: OCTA can be used to image and quantify non-invasively the vascular retinal networks of the canine retina. We provide normative data in eight different retinal locations that can be imaged non-invasively with this technology. This could support analysis of retinal vascular changes associated with disease and following therapeutic intervention.
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Affiliation(s)
- Ana Ripolles-Garcia
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Gordon Ruthel
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Gui-Shuang Ying
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Yineng Chen
- Department of Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Nicolas Cuenca
- Department of Physiology, Genetics and Microbiology, University of Alicante, Alicante, Spain
| | - Gustavo D. Aguirre
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - William A. Beltran
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, United States
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29
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McKay KM, Chu Z, Kim JB, Legocki A, Zhou X, Tian M, Munk MR, Wang RK, Pepple KL. Automated Quantification of Choriocapillaris Lesion Area in Patients With Posterior Uveitis. Am J Ophthalmol 2021; 231:179-193. [PMID: 34107308 PMCID: PMC8608733 DOI: 10.1016/j.ajo.2021.06.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 04/26/2021] [Accepted: 06/01/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE To validate a custom algorithm for automated identification and quantification of clinically relevant inflammatory choriocapillaris (CC) lesions from en face swept-source optical coherence tomography (SS-OCTA) images. DESIGN Observational case series. METHODS Twenty eyes of 14 patients with posterior uveitis were imaged. The machine-generated en face OCTA CC slabs were exported to a computing platform, where a custom algorithm performed unsupervised lesion boundary delineation and area quantification. Lesions identified by the algorithm (AG) were compared to those identified by 2 masked human graders (HG1 and HG2), using the Sørensen-Dice coefficient (DSC) and intraclass correlation coefficient (ICC). Intragrader and intravisit reliability were determined by coefficient of variation (CV) and DSC. RESULTS The AG demonstrated excellent agreement with both HGs in determination of lesion area (HG1 vs AG ICC 0.92, 95% CI 0.81-0.97, HG2 vs AG ICC 0.91, 95% CI 0.78-0.97). The AG demonstrated good spatial overlap (DSC ≥0.70) with both HGs in 14 of 20 (70%) eyes and at least 1 HG in 16 of 20 (80%) eyes. Poor spatial overlap (DSC between 0.31 and 0.69) was associated with the presence of a choroidal neovascular membrane and low-contrast lesion boundaries. Intravisit repeatability for the AG was superior to both HGs (CV 2.6% vs >5%). CONCLUSION This custom algorithm demonstrated a high degree of agreement with HGs in identification of inflammatory CC lesions and outperformed HGs in reproducibility. Automated CC lesion delineation will support the development of objective and quantitative biomarker of disease activity in patients with posterior uveitis.
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Affiliation(s)
- K Matthew McKay
- Department of Ophthalmology, University of Washington, Seattle, Washington, USA
| | - Zhongdi Chu
- Departments of Ophthalmology and Bioengineering, University of Washington, Seattle, Washington, USA
| | - Joon-Bom Kim
- Department of Ophthalmology, University of Washington, Seattle, Washington, USA
| | - Alex Legocki
- Department of Ophthalmology, University of Washington, Seattle, Washington, USA
| | - Xiao Zhou
- Departments of Ophthalmology and Bioengineering, University of Washington, Seattle, Washington, USA
| | - Meng Tian
- Department of Ophthalmology and Bern Photographic Reading Center, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Marion R Munk
- Department of Ophthalmology and Bern Photographic Reading Center, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Ruikang K Wang
- Department of Ophthalmology, University of Washington, Seattle, Washington, USA; Departments of Ophthalmology and Bioengineering, University of Washington, Seattle, Washington, USA
| | - Kathryn L Pepple
- Department of Ophthalmology, University of Washington, Seattle, Washington, USA.
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30
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Le P, Zehden J, Zhang AY. Role of Optical Coherence Tomography Angiography Imaging in Patients with Diabetes. Curr Diab Rep 2021; 21:42. [PMID: 34665347 DOI: 10.1007/s11892-021-01405-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/26/2021] [Indexed: 11/30/2022]
Abstract
PURPOSE OF REVIEW Ocular manifestations in patients with diabetes mellitus (DM) can present as microvascular changes. These microvascular changes can be challenging to identify on exams, and imaging technologies have commonly aided in the diagnosis and management of patients with DM. Optical coherence tomography angiography (OCTA) provides noninvasive image segmentation of various layers of the retina and choroid. Also, post-processing of images and associated quantitative measurements offer potential clinical enhancements. Our aim is to review the current evidence on the utility of OCTA for patients with DM. RECENT FINDINGS Research suggests OCTA to potentially provide potential clinical enhancements and alternative methods in detecting subclinical manifestation of diabetic retinopathy, staging diabetic retinopathy, management of diabetic macular edema, and monitoring of systemic markers in patients with diabetes mellitus. OCTA is a promising but relatively new modality, and differences in terminology, research designs, and image processing techniques provide a difficult landscape to navigate. Standardization within further validation is needed to determine the extent of OCTA's clinical utility, but the current literature suggests the potential for earlier detection of ocular manifestations in patients with DM, additional objective measurements for grading and management, and opportunity for additional biomarkers for treatment outcomes.
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Affiliation(s)
- Patrick Le
- Department of Ophthalmology, University of North Carolina At Chapel Hill, Chapel Hill, NC, USA
| | - Jason Zehden
- Department of Ophthalmology, University of North Carolina At Chapel Hill, Chapel Hill, NC, USA
| | - Alice Yang Zhang
- Department of Ophthalmology, University of North Carolina At Chapel Hill, Chapel Hill, NC, USA.
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31
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Leitgeb R, Placzek F, Rank E, Krainz L, Haindl R, Li Q, Liu M, Andreana M, Unterhuber A, Schmoll T, Drexler W. Enhanced medical diagnosis for dOCTors: a perspective of optical coherence tomography. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210150-PER. [PMID: 34672145 PMCID: PMC8528212 DOI: 10.1117/1.jbo.26.10.100601] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/23/2021] [Indexed: 05/17/2023]
Abstract
SIGNIFICANCE After three decades, more than 75,000 publications, tens of companies being involved in its commercialization, and a global market perspective of about USD 1.5 billion in 2023, optical coherence tomography (OCT) has become one of the fastest successfully translated imaging techniques with substantial clinical and economic impacts and acceptance. AIM Our perspective focuses on disruptive forward-looking innovations and key technologies to further boost OCT performance and therefore enable significantly enhanced medical diagnosis. APPROACH A comprehensive review of state-of-the-art accomplishments in OCT has been performed. RESULTS The most disruptive future OCT innovations include imaging resolution and speed (single-beam raster scanning versus parallelization) improvement, new implementations for dual modality or even multimodality systems, and using endogenous or exogenous contrast in these hybrid OCT systems targeting molecular and metabolic imaging. Aside from OCT angiography, no other functional or contrast enhancing OCT extension has accomplished comparable clinical and commercial impacts. Some more recently developed extensions, e.g., optical coherence elastography, dynamic contrast OCT, optoretinography, and artificial intelligence enhanced OCT are also considered with high potential for the future. In addition, OCT miniaturization for portable, compact, handheld, and/or cost-effective capsule-based OCT applications, home-OCT, and self-OCT systems based on micro-optic assemblies or photonic integrated circuits will revolutionize new applications and availability in the near future. Finally, clinical translation of OCT including medical device regulatory challenges will continue to be absolutely essential. CONCLUSIONS With its exquisite non-invasive, micrometer resolution depth sectioning capability, OCT has especially revolutionized ophthalmic diagnosis and hence is the fastest adopted imaging technology in the history of ophthalmology. Nonetheless, OCT has not been completely exploited and has substantial growth potential-in academics as well as in industry. This applies not only to the ophthalmic application field, but also especially to the original motivation of OCT to enable optical biopsy, i.e., the in situ imaging of tissue microstructure with a resolution approaching that of histology but without the need for tissue excision.
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Affiliation(s)
- Rainer Leitgeb
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
- Medical University of Vienna, Christian Doppler Laboratory OPTRAMED, Vienna, Austria
| | - Fabian Placzek
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Elisabet Rank
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Lisa Krainz
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Richard Haindl
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Qian Li
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Mengyang Liu
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Marco Andreana
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Angelika Unterhuber
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
| | - Tilman Schmoll
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
- Carl Zeiss Meditec, Inc., Dublin, California, United States
| | - Wolfgang Drexler
- Medical University of Vienna, Center for Medical Physics and Biomedical Engineering, Vienna, Austria
- Address all correspondence to Wolfgang Drexler,
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32
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Jiao S, Jia Y, Yao X. Emerging imaging developments in experimental vision sciences and ophthalmology. Exp Biol Med (Maywood) 2021; 246:2137-2139. [PMID: 34404253 PMCID: PMC8718248 DOI: 10.1177/15353702211038891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Shuliang Jiao
- Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA
| | - Yali Jia
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Xincheng Yao
- Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
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Romond K, Alam M, Kravets S, Sisternes LD, Leng T, Lim JI, Rubin D, Hallak JA. Imaging and artificial intelligence for progression of age-related macular degeneration. Exp Biol Med (Maywood) 2021; 246:2159-2169. [PMID: 34404252 DOI: 10.1177/15353702211031547] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of severe vision loss. With our aging population, it may affect 288 million people globally by the year 2040. AMD progresses from an early and intermediate dry form to an advanced one, which manifests as choroidal neovascularization and geographic atrophy. Conversion to AMD-related exudation is known as progression to neovascular AMD, and presence of geographic atrophy is known as progression to advanced dry AMD. AMD progression predictions could enable timely monitoring, earlier detection and treatment, improving vision outcomes. Machine learning approaches, a subset of artificial intelligence applications, applied on imaging data are showing promising results in predicting progression. Extracted biomarkers, specifically from optical coherence tomography scans, are informative in predicting progression events. The purpose of this mini review is to provide an overview about current machine learning applications in artificial intelligence for predicting AMD progression, and describe the various methods, data-input types, and imaging modalities used to identify high-risk patients. With advances in computational capabilities, artificial intelligence applications are likely to transform patient care and management in AMD. External validation studies that improve generalizability to populations and devices, as well as evaluating systems in real-world clinical settings are needed to improve the clinical translations of artificial intelligence AMD applications.
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Affiliation(s)
- Kathleen Romond
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Minhaj Alam
- Department of Biomedical Data Science, Stanford University, Stanford, CA 94304, USA
| | - Sasha Kravets
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA.,Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, Chicago, IL 60612, USA
| | | | - Theodore Leng
- Byers Eye Institute at Stanford, Stanford University School of Medicine, Palo Alto, CA 94303, USA
| | - Jennifer I Lim
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Daniel Rubin
- Department of Biomedical Data Science, Stanford University, Stanford, CA 94304, USA
| | - Joelle A Hallak
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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Vujosevic S, Cunha-Vaz J, Figueira J, Löwenstein A, Midena E, Parravano M, Scanlon PH, Simó R, Hernández C, Madeira MH, Marques IP, C-V Martinho A, Santos AR, Simó-Servat O, Salongcay RP, Zur D, Peto T. Standardisation of Optical Coherence Tomography Angiography Imaging Biomarkers in Diabetic Retinal Disease. Ophthalmic Res 2021; 64:871-887. [PMID: 34348330 DOI: 10.1159/000518620] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/12/2021] [Indexed: 11/19/2022]
Affiliation(s)
| | - José Cunha-Vaz
- AIBILI-Association for Innovation and Biomedical Research on Light and Image, Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - João Figueira
- AIBILI-Association for Innovation and Biomedical Research on Light and Image, Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Anat Löwenstein
- Ophthalmology Division, Tel Aviv Medical Center, affiliated to Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Edoardo Midena
- Department of Neuroscience, University of Padua, Padua, Italy
| | | | - Peter Henry Scanlon
- Department of Ophthalmology, Gloucestershire Hospitals NHS Foundation Trust, Cheltenham, United Kingdom
| | - Rafael Simó
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Hernández
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Maria H Madeira
- AIBILI-Association for Innovation and Biomedical Research on Light and Image, Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Inês P Marques
- AIBILI-Association for Innovation and Biomedical Research on Light and Image, Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
- Department of Orthoptics, School of Health, Polytechnic of Porto, Porto, Portugal
| | - António C-V Martinho
- AIBILI-Association for Innovation and Biomedical Research on Light and Image, Coimbra, Portugal
| | - Ana R Santos
- AIBILI-Association for Innovation and Biomedical Research on Light and Image, Coimbra, Portugal
- Department of Orthoptics, School of Health, Polytechnic of Porto, Porto, Portugal
| | - Olga Simó-Servat
- Diabetes and Metabolism Research Unit, Vall d'Hebron Research Institute, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Recivall P Salongcay
- Centre for Public Health, Queen's University Belfast, Belfast, United Kingdom
- Eye and Vision Institute, The Medical City, Pasig, Philippines
| | - Dinah Zur
- Ophthalmology Division, Tel Aviv Medical Center, affiliated to Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Tunde Peto
- Centre for Public Health, Queen's University Belfast, Belfast, United Kingdom
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Dadkhah A, Paudel D, Jiao S. Comparative study of optical coherence tomography angiography algorithms for rodent retinal imaging. Exp Biol Med (Maywood) 2021; 246:2207-2213. [PMID: 34120494 DOI: 10.1177/15353702211024572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Optical coherence tomography angiography (OCTA) is a functional extension of optical coherence tomography for non-invasive in vivo three-dimensional imaging of the microvasculature of biological tissues. Several algorithms have been developed to construct OCTA images from the measured optical coherence tomography signals. In this study, we compared the performance of three OCTA algorithms that are based on the variance of phase, amplitude, and the complex representations of the optical coherence tomography signals for rodent retinal imaging, namely the phase variance, improved speckle contrast, and optical microangiography. The performance of the different algorithms was evaluated by comparing the quality of the OCTA images regarding how well the vasculature network can be resolved. Quantities that are widely used in ophthalmic studies including blood vessel density, vessel diameter index, vessel perimeter index, vessel complexity index were also compared. Results showed that both the improved speckle contrast and optical microangiography algorithms are more robust than phase variance, and they can reveal similar vasculature features while there are statistical differences in the calculated quantities.
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Affiliation(s)
- Arash Dadkhah
- Department of Biomedical Engineering, 5450Florida International University, Miami, FL 33174, USA
| | - Dhruba Paudel
- Department of Biomedical Engineering, 5450Florida International University, Miami, FL 33174, USA
| | - Shuliang Jiao
- Department of Biomedical Engineering, 5450Florida International University, Miami, FL 33174, USA
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Yao X, Lu R, Wang B, Lu Y, Kim TH. Super-resolution ophthalmoscopy: Virtually structured detection for resolution improvement in retinal imaging. Exp Biol Med (Maywood) 2021; 246:249-259. [PMID: 33243006 PMCID: PMC7876641 DOI: 10.1177/1535370220970533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Quantitative retinal imaging is essential for advanced study and clinical management of eye diseases. However, spatial resolution of retinal imaging has been limited due to available numerical aperture and optical aberration of the ocular optics. Structured illumination microscopy has been established to break the diffraction-limit resolution in conventional light microscopy. However, practical implementation of structured illumination microscopy for in vivo ophthalmoscopy of the retina is challenging due to inevitable eye movements that can produce phase artifacts. Recently, we have demonstrated the feasibility of using virtually structured detection as one alternative to structured illumination microscopy for super-resolution imaging. By providing the flexibility of digital compensation of eye movements, the virtually structured detection provides a feasible, phase-artifact-free strategy to achieve super-resolution ophthalmoscopy. In this article, we summarize the technical rationale of virtually structured detection, and its implementations for super-resolution imaging of freshly isolated retinas, intact animals, and awake human subjects.
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Affiliation(s)
- Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Rongwen Lu
- National Eye Institute, National Institutes of Health, Bethesda, MD 20814, USA
| | - Benquan Wang
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Yiming Lu
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
| | - Tae-Hoon Kim
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
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Laiginhas R, Guimarães M, Nora M, Chibante J, Falcão M. Gastric Bypass Improves Microvascular Perfusion in Patients with Obesity. Obes Surg 2021; 31:2080-2086. [PMID: 33420672 DOI: 10.1007/s11695-021-05223-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/11/2022]
Abstract
PURPOSE Basic science research has shown that obesity is associated with microvascular endothelial dysfunction. However, whether bariatric surgery impacts the microvascular networks has yet to be explored. This study sought to evaluate the impact of gastric bypass in the retinal microvasculature. METHODS Patients with obesity (BMI ≥ 35 kg/m2) scheduled to gastric bypass were consecutively recruited and included in the study. Patients were evaluated before surgery and 6-12 months after the intervention. Macular microvascular properties were evaluated using optical coherence tomography (OCT) angiography. Foveal avascular zone area, perimeter, circularity, and foveal and perifoveal vascular density (in both superficial and deep vascular plexus) were computed. RESULTS In total, 40 eyes from 20 patients were included (30% male, mean BMI 43.4 ± 4.5 kg/m2 (range 35.7-51.4). From these, 45% were diabetic before bariatric surgery. After surgery, there was a significant increase in foveal avascular zone circularity (from 0.85 ± 0.09 to 0.92 ± 0.07, p = 0.001) and vascular density in perifoveal deep vascular plexus (from 0.69 ± 0.12 to 0.73 ± 0.12; p = 0.04), whereas foveal avascular zone perimeter decreased (from 2.34 ± 0.37 to 2.20 ± 0.35 mm, p = 0.007). Preoperative diabetic status was not a predictor of microvascular retinal changes after bariatric surgery. However, after multivariate adjustments, the increased drop in HbA1c after the surgery remained associated with the increase in perifoveal vascular density in the deep vascular plexus (B = 0.05; 95% CI 0.05-0.10; p = 0.03). CONCLUSIONS Gastric bypass improves retinal microvascular perfusion as demonstrated by the increased parafoveal vascular density in the deep vascular plexus, increased foveal avascular zone circularity, and decreased foveal avascular zone perimeter.
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Affiliation(s)
- Rita Laiginhas
- PDICSS, Faculty of Medicine of Porto University (FMUP), Porto, Portugal
- Department of Ophthalmology, Centro Hospitalar de Entre o Douro e Vouga, Santa Maria da Feira, Portugal
| | - Marta Guimarães
- Department of General Surgery, Centro Hospitalar de Entre Douro e Vouga, Santa Maria da Feira, Portugal
- Unit for Multidisciplinary Research in Biomedicine (UMIB), Endocrine, Cardiovascular and Metabolic Research, University of Porto, Porto, Portugal
- Department of Anatomy, Institute of Biomedical Science Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Mário Nora
- Department of General Surgery, Centro Hospitalar de Entre Douro e Vouga, Santa Maria da Feira, Portugal
- Unit for Multidisciplinary Research in Biomedicine (UMIB), Endocrine, Cardiovascular and Metabolic Research, University of Porto, Porto, Portugal
- Department of Anatomy, Institute of Biomedical Science Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - João Chibante
- Department of Ophthalmology, Centro Hospitalar de Entre o Douro e Vouga, Santa Maria da Feira, Portugal
| | - Manuel Falcão
- Department of Ophthalmology, Centro Hospitalar e Universitário São João, Porto, Portugal.
- Department of Surgery and Physiology, Faculty of Medicine of Porto University (FMUP), Porto, Portugal.
- Faculty of Medicine of the University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319, Porto, Portugal.
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Kim TH, Le D, Son T, Yao X. Vascular morphology and blood flow signatures for differential artery-vein analysis in optical coherence tomography of the retina. BIOMEDICAL OPTICS EXPRESS 2021; 12:367-379. [PMID: 33520388 PMCID: PMC7818960 DOI: 10.1364/boe.413149] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/07/2020] [Accepted: 12/09/2020] [Indexed: 05/09/2023]
Abstract
Differential artery-vein (AV) analysis is essential for retinal study, disease detection, and treatment assessment. This study is to characterize vascular reflectance profiles and blood flow patterns of retinal artery and vein systems in optical coherence tomography (OCT) and OCT angiography (OCTA), and establish them as robust signatures for objective AV classification. A custom designed OCT was employed for three-dimensional (3D) imaging of mouse retina, and corresponding OCTA was reconstructed. Radially resliced OCT B-scans revealed two, i.e. top and bottom, hyperreflective wall boundaries in retinal arteries, while these wall boundaries were absent in OCT of retinal veins. Additional OCTA analysis consistently displayed a layered speckle distribution in the vein, which may indicate the venous laminar flow. These OCT and OCTA differences offer unique signatures for objective AV classification in OCT and OCTA.
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Affiliation(s)
- Tae-Hoon Kim
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - David Le
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Taeyoon Son
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Xincheng Yao
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA
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Everett M, Magazzeni S, Schmoll T, Kempe M. Optical coherence tomography: From technology to applications in ophthalmology. TRANSLATIONAL BIOPHOTONICS 2020. [DOI: 10.1002/tbio.202000012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
| | | | - Tilman Schmoll
- Carl Zeiss Meditec Inc. Dublin California USA
- Center for Medical Physics and Biomedical Engineering Medical University of Vienna Vienna Austria
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40
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Jiao S. Biomedical optical imaging technology and applications: From basic research toward clinical diagnosis. Exp Biol Med (Maywood) 2020; 245:269-272. [PMID: 32141780 DOI: 10.1177/1535370220909543] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Affiliation(s)
- Shuliang Jiao
- Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA
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