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    1. OCTA Multilayer and Multisector Peripapillary Microvascular Modeling for Diagnosing and Staging of Glaucoma

      OCTA Multilayer and Multisector Peripapillary Microvascular Modeling for Diagnosing and Staging of Glaucoma

      Purpose: To develop and assess an automatic procedure for classifying and staging glaucomatous vascular damage based on optical coherence tomography angiography (OCTA) imaging. Methods: OCTA scans (Zeiss Cirrus 5000 HD-OCT) from a random eye of 39 healthy subjects and 82 glaucoma patients were used to develop a new classification algorithm based on multilayer and multisector information. The averaged circumpapillary retinal nerve fiber layer (RNFL) thickness was also collected. Three models, support vector machine (SVM), random forest (RF), and gradient boosting (xGB), were developed and optimized for classifying between healthy and glaucoma patients, primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG ...

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    2. Combined Multi-Modal Assessment of Glaucomatous Damage With Electroretinography and Optical Coherence Tomography/Angiography

      Combined Multi-Modal Assessment of Glaucomatous Damage With Electroretinography and Optical Coherence Tomography/Angiography

      Abstract Purpose : To compare the diagnostic performance and to evaluate the interrelationship of electroretinographical and structural and vascular measures in glaucoma. Methods : For 14 eyes of 14 healthy controls and 15 eyes of 12 patients with glaucoma ranging from preperimetric to advanced stages optical coherence tomography (OCT), OCT-angiography (OCT-A), and electrophysiological measures (multifocal photopic negative response ratio [mfPhNR] and steady-state pattern electroretinography [ssPERG]) were applied to assess changes in retinal structure, microvasculature, and function, respectively. The diagnostic performance was assessed via area-under-curve (AUC) measures obtained from receiver operating characteristics analyses. The interrelation of the different measures was assessed with correlation ...

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    3. Improved Automated Foveal Avascular Zone Measurement in Cirrus Optical Coherence Tomography Angiography Using the Level Sets Macro

      Improved Automated Foveal Avascular Zone Measurement in Cirrus Optical Coherence Tomography Angiography Using the Level Sets Macro

      Purpose : To evaluate automated measurements of the foveal avascular zone (FAZ) using the Level Sets macro (LSM) in ImageJ as compared with the Cirrus optical coherence tomography angiography (OCTA) inbuilt algorithm and the Kanno–Saitama macro (KSM). Methods : The eyes of healthy volunteers were scanned four times consecutively on the Zeiss Cirrus HD-OCT 5000 system. The FAZ metrics (area, perimeter, and circularity) were measured manually and automatically by the Cirrus inbuilt algorithm, the KSM, and the LSM. The accuracy and repeatability of all methods and agreement between automated and manual methods were evaluated. Results : The LSM segmented the FAZ with ...

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    4. Pathological-Corneas Layer Segmentation and Thickness Measurement in OCT Images

      Pathological-Corneas Layer Segmentation and Thickness Measurement in OCT Images

      Purpose : The purpose of this study was to propose a new algorithm for the segmentation and thickness measurement of pathological corneas with irregular layers using a two-stage graph search and ray tracing. Methods : In the first stage, a graph, with only gradient edge-cost, is used to segment the air-epithelium and endothelium-aqueous boundaries. In the second stage, a graph, with gradient, directional, and multiplier edge-cost, is used to correct segmentation. The optical coherence tomography (OCT) image is flattened using the air-epithelium boundary and a graph search is used to segment the epithelium-Bowman's and Bowman's-stroma boundaries. Then, the OCT image ...

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    5. A Novel Approach to Quantitative Evaluation of Outer Retinal Lesions Via a New Parameter “Integral” in Spectral Domain Optical Coherence Tomography

      A Novel Approach to Quantitative Evaluation of Outer Retinal Lesions Via a New Parameter “Integral” in Spectral Domain Optical Coherence Tomography

      Purpose : The purpose of this study was to design a new parameter “integral” to quantitatively evaluate the spatial cumulative reflectivity of the outer retinal layers in optical coherence tomography (OCT), and to investigate its role in the detection of outer retinal diseases. Methods : This was a cross-sectional study. Fovea-centered line OCT scans were performed on 60 eyes of 60 healthy volunteers and 44 eyes of 44 patients diagnosed with outer retinal diseases. The integrals of the ellipsoid zone (EZ) and interdigitation zone (IZ) were measured by respectively accumulating the grayscale values of all the pixels within the EZ and IZ ...

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      Mentions: Fudan University
    6. Reasons why OCT Global Circumpapillary Retinal Nerve Fiber Layer Thickness is a Poor Measure of Glaucomatous Progression

      Reasons why OCT Global Circumpapillary Retinal Nerve Fiber Layer Thickness is a Poor Measure of Glaucomatous Progression

      Purpose: To assess the effects of local defects, segmentation errors, and improper image alignment on the performance of the commonly used optical coherence tomography (OCT) measure of progression, that is the change in global (average) circumpapillary retinal nerve fiber layer (cpRNFL) thickness (ΔG). Methods: One hundred fifty eyes suspected of, or with, early glaucoma had OCT circle and cube scans obtained using eye tracking on two occasions at least 1 year apart. Statistical progression was defined by fixed values of ΔG (3-8 um) and quantile regression. For a reference standard, four authors identified 30 eyes as "likely progressed," and 61 ...

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    7. Artificial Intelligence Algorithms to Diagnose Glaucoma and Detect Glaucoma Progression: Translation to Clinical Practice

      Artificial Intelligence Algorithms to Diagnose Glaucoma and Detect Glaucoma Progression: Translation to Clinical Practice

      Purpose : This concise review aims to explore the potential for the clinical implementation of artificial intelligence (AI) strategies for detecting glaucoma and monitoring glaucoma progression. Methods : Nonsystematic literature review using the search combinations “Artificial Intelligence,” “Deep Learning,” “Machine Learning,” “Neural Networks,” “Bayesian Networks,” “Glaucoma Diagnosis,” and “Glaucoma Progression.” Information on sensitivity and specificity regarding glaucoma diagnosis and progression analysis as well as methodological details were extracted. Results : Numerous AI strategies provide promising levels of specificity and sensitivity for structural (e.g. optical coherence tomography [OCT] imaging, fundus photography) and functional (visual field [VF] testing) test modalities used for the detection ...

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    8. Anatomical Location of the Raphe and Extended Raphe in the Human Retina: Implications for Assessment of the Optic Nerve with OCT

      Anatomical Location of the Raphe and Extended Raphe in the Human Retina: Implications for Assessment of the Optic Nerve with OCT

      Abstract Purpose : To determine the location of (1) the superior–inferior watershed between the fovea and optic disc (extended raphe) at the peripapillary optical coherence tomography (OCT) measurement circle and (2) the raphe, temporal to the fovea. Methods : We used existing data consisting of 2285 traced retinal nerve fiber bundle trajectories from 83 fundus images. For localization of the extended raphe at the 3.46-mm-diameter OCT measurement circle, trajectories were classified as belonging to the superior or inferior hemiretina, using predefined criteria. For the raphe, we localized the endings of trajectories coming from the superior and inferior arcuate bundles. Results ...

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    9. Assessing the Influence of OCT-A Device and Scan Size on Retinal Vascular Metrics

      Assessing the Influence of OCT-A Device and Scan Size on Retinal Vascular Metrics

      Purpose : The purpose of this study was to investigate the effect of device and scan size on quantitative optical coherence tomography angiography (OCT-A) metrics. Methods : The 3 × 3 mm scans from Optovue AngioVue and Zeiss AngioPlex systems were included for 18 eyes of 18 subjects without ocular pathology. The foveal avascular zone (FAZ) was segmented manually by two observers, from which estimates of FAZ area (using both the nominal image scale and the axial length corrected image scale) and acircularity were derived. Three scan sizes (3 mm, 6 mm HD, and 8 mm) from the AngioVue system were included for ...

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    10. Repeatability and Reproducibility of Axial and Lateral Measurements on Handheld Optical Coherence Tomography Systems Compared with Tabletop System

      Repeatability and Reproducibility of Axial and Lateral Measurements on Handheld Optical Coherence Tomography Systems Compared with Tabletop System

      Purpose : To compare the repeatability and reproducibility of axial and lateral retinal measurements using handheld optical coherence tomography (OCT) systems and a tabletop OCT system. Methods : Graders measured central foveal thickness (CFT), optic nerve-to-fovea distance (OFD), and retinal nerve fiber layer (RNFL) thickness on OCT scans of the right eye of 10 healthy adults. Three OCT systems were used: handheld Leica Envisu, investigational handheld swept-source OCT (UC3), and Heidelberg Spectralis tabletop system. All eyes were imaged five times with each OCT system by each of two imagers. A components of variance analysis provided estimates of repeatability (variation due to random ...

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    11. In Vivo 3D Determination of Peripapillary Scleral and Retinal Layer Architecture Using Polarization-Sensitive Optical Coherence Tomography

      In Vivo 3D Determination of Peripapillary Scleral and Retinal Layer Architecture Using Polarization-Sensitive Optical Coherence Tomography

      Purpose : The purpose of this paper was to determine the architecture of the collagen fibers of the peripapillary sclera, the retinal nerve fiber layer (RNFL), and Henle's fiber layer in vivo in 3D using polarization-sensitive optical coherence tomography (PS-OCT). Methods : Seven healthy volunteers were imaged with our in-house built PS-OCT system. PS-OCT imaging included intensity, local phase retardation, relative optic axis, and optic axis uniformity (OAxU). Differential Mueller matrix calculus was used for the first time in ocular tissues to visualize local orientations that varied with depth, incorporating a correction method for the fiber orientation in preceding layers. Results ...

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    12. Validation of an Automated Quantification of Relative Ellipsoid Zone Reflectivity on Spectral Domain-Optical Coherence Tomography Images

      Validation of an Automated Quantification of Relative Ellipsoid Zone Reflectivity on Spectral Domain-Optical Coherence Tomography Images

      Purpose : Relative ellipsoid zone reflectivity (rEZR) represents a potential biomarker of photoreceptor health on spectral-domain optical coherence tomography (SD-OCT). Because manual quantification of rEZR is laborious and lacks of spatial resolution, automated quantification of the rEZR would be beneficial. The purpose of this study was to evaluate the reliability and reproducibility of an automated rEZR quantification method. Methods : The rEZR was acquired using a manual and an automated approach in eyes with age-related macular degeneration (AMD) and healthy controls. The rEZR obtained from both methods was compared and the agreement between the methods and their reproducibility assessed. Results : Forty eyes ...

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    13. Retinal Boundary Segmentation in Stargardt Disease Optical Coherence Tomography Images Using Automated

      Retinal Boundary Segmentation in Stargardt Disease Optical Coherence Tomography Images Using Automated

      Purpose : To use a deep learning model to develop a fully automated method (fully semantic network and graph search [FS-GS]) of retinal segmentation for optical coherence tomography (OCT) images from patients with Stargardt disease. Methods : Eighty-seven manually segmented (ground truth) OCT volume scan sets (5171 B-scans) from 22 patients with Stargardt disease were used for training, validation and testing of a novel retinal boundary detection approach (FS-GS) that combines a fully semantic deep learning segmentation method, which generates a per-pixel class prediction map with a graph-search method to extract retinal boundary positions. The performance was evaluated using the mean absolute ...

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    14. Visible-Light Optical Coherence Tomography Fibergraphy for Quantitative Imaging of Retinal Ganglion Cell Axon Bundles

      Visible-Light Optical Coherence Tomography Fibergraphy for Quantitative Imaging of Retinal Ganglion Cell Axon Bundles

      Purpose : To develop a practical technique for visualizing and quantifying retinal ganglion cell (RGC) axon bundles in vivo. Methods : We applied visible-light optical coherence tomography (vis-OCT) to image the RGC axon bundles, referred to as vis-OCT fibergraphy, of healthy wild-type C57BL/6 mice. After vis-OCT imaging, retinas were flat-mounted, immunostained with anti-beta-III tubulin (Tuj1) antibody for RGC axons, and imaged with confocal microscopy. We quantitatively compared the RGC axon bundle networks imaged by in vivo vis-OCT and ex vivo confocal microscopy using semi-log Sholl analysis. Results : Side-by-side comparison of ex vivo confocal microscopy and in vivo vis-OCT confirmed that vis-OCT ...

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    15. Optical Coherence Tomography Angiography in Macular Neovascularization: A Comparison Between Different OCTA Devices

      Optical Coherence Tomography Angiography in Macular Neovascularization: A Comparison Between Different OCTA Devices

      Purpose : The purpose of this study is to compare the ability of 3 optical coherence tomography angiography (OCTA) devices to measure lesion area in patients with macular neovascularization (MNV) with type 1, 2 and mixed neovascularization (NV). Methods : OCTA, fluorescein angiography (FA), indocyanine green angiography (ICGA), and structural optical coherence tomography (OCT) were performed. NV lesion area measurements were performed by two graders. Results : Twenty-eight eyes were included: 20 with NV were classified as type 1, 6 as type 2, and 2 as mixed type. AngioVue and Spectralis detected the NV in 26 out of 28 eyes (92.8%). The ...

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    16. Optical Coherence Tomography Angiography in Type 1 Diabetes Mellitus. Report 1: Diabetic Retinopathy

      Optical Coherence Tomography Angiography in Type 1 Diabetes Mellitus. Report 1: Diabetic Retinopathy

      Purpose : The purpose of this study was to evaluate specifically in type 1 diabetes mellitus (DM) individuals the relationship between perifoveal superficial capillary plexus (SCP) parameters assessed by optical coherence tomography angiography (OCTA) and diabetic retinopathy (DR) grade. Methods : Cross-sectional analysis of a large scale prospective OCTA trial cohort (ClinicalTrials.gov NCT03422965). A total of 1186 eyes (593 individuals), 956 type 1 DM eyes (478 patients), and 230 control eyes (115 healthy volunteers) were included in this study. DR stage was graded according to the International Classification. OCTA imaging was performed with a commercially available device (Cirrus HD-OCT). Vessel density ...

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    17. Matching Misaligned Spectralis OCTs to a Reference Scan in Pediatric Glaucoma with Poor Fixation and Nystagmus

      Matching Misaligned Spectralis OCTs to a Reference Scan in Pediatric Glaucoma with Poor Fixation and Nystagmus

      Purpose : Poor fixation or nystagmus in children causes misalignment errors when measuring circumpapillary retinal nerve fiber layer (cpRNFL) thickness by simultaneous scanning laser ophthalmoscope imaging/optical coherence tomography (SLO/OCT). We investigated a method to assess cpRNFL from misaligned SLO/OCT scans. Methods : Heidelberg Spectralis SLO/OCT scans from a single clinical examination were retrospectively analyzed when automated eye tracking was unreliable. Retinal layer thickness was measured at overlapping match locations between a reference and misaligned scans based on the position data from simultaneously acquired SLO images. Three layers were segmented: cpRNFL, internal limiting membrane to outer nuclear layer (ILM-ONL ...

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    18. Comparison and Repeatability of High Resolution and High Speed Scans from Spectralis Optical Coherence Tomography Angiography

      Comparison and Repeatability of High Resolution and High Speed Scans from Spectralis Optical Coherence Tomography Angiography

      Purpose : The purpose of this study was to evaluate and compare the repeatability of optical coherence tomography angiography (OCTA) derived retinal vascular quantitative metrics using high resolution (HR) versus high speed (HS) acquisition modes. Methods : Macular 4.4 × 2.9-mm OCTA images from normal, healthy volunteers were captured using both HR (768 A-scans × 256 B-scans) and HS (384 A-scans × 256 B-scans) acquisition protocols. Vessel density and vessel length density of the superficial capillary plexus and deep capillary plexus, as well as choriocapillaris flow deficit were computed. In a subset of eyes, the OCTA scans were repeated twice 2 days later ...

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    19. Artifact Rates for 2D Retinal Nerve Fiber Layer Thickness Versus 3D Neuroretinal Rim Thickness Using Spectral-Domain Optical Coherence Tomography

      Artifact Rates for 2D Retinal Nerve Fiber Layer Thickness Versus 3D Neuroretinal Rim Thickness Using Spectral-Domain Optical Coherence Tomography

      Purpose : To compare the rates of clinically significant artifacts for two-dimensional peripapillary retinal nerve fiber layer (RNFL) thickness versus three-dimensional (3D) neuroretinal rim thickness using spectral-domain optical coherence tomography (SD-OCT). Methods : Only one eye per patient was used for analysis of 120 glaucoma patients and 114 normal patients. For RNFL scans and optic nerve scans, 15 artifact types were calculated per B-scan and per eye. Neuroretinal rim tissue was quantified by the minimum distance band (MDB). Global MDB neuroretinal rim thicknesses were calculated before and after manual deletion of B-scans with artifacts and subsequent automated interpolation. A clinically significant artifact ...

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    20. Development of Deep Learning Models to Predict Best-Corrected Visual Acuity from Optical Coherence Tomography

      Development of Deep Learning Models to Predict Best-Corrected Visual Acuity from Optical Coherence Tomography

      Purpose : To develop deep learning (DL) models to predict best-corrected visual acuity (BCVA) from optical coherence tomography (OCT) images from patients with neovascular age-related macular degeneration (nAMD). Methods : Retrospective analysis of OCT images and associated BCVA measurements from the phase 3 HARBOR trial (NCT00891735). DL regression models were developed to predict BCVA at the concurrent visit and 12 months from baseline using OCT images. Binary classification models were developed to predict BCVA of Snellen equivalent of <20/40, <20/60, and ≤20/200 at the concurrent visit and 12 months from baseline. Results : The regression model to predict BCVA at ...

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    21. An Artificial Intelligence Approach to Assess Spatial Patterns of Retinal Nerve Fiber Layer Thickness Maps in Glaucoma

      An Artificial Intelligence Approach to Assess Spatial Patterns of Retinal Nerve Fiber Layer Thickness Maps in Glaucoma

      Purpose : The purpose of this study was to classify the spatial patterns of retinal nerve fiber layer thickness (RNFLT) and assess their associations with visual field (VF) loss in glaucoma. Methods : We used paired reliable 24-2 VFs and optical coherence tomography scans of 691 eyes from 691 patients. The RNFLT maps were used to determine the RNFLT patterns (RPs) by non-negative matrix factorization (NMF). The RPs were correlated with mean deviation (MD), spherical equivalent (SE), and major blood vessel locations. The RPs were further used to predict the 52 total deviation (TD) values by linear regression compared with models using ...

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    22. Quantitative Optical Coherence Tomography Angiography Parameters in Type 1 Macular Neovascularization Secondary to Age-Related Macular Degeneration

      Quantitative Optical Coherence Tomography Angiography Parameters in Type 1 Macular Neovascularization Secondary to Age-Related Macular Degeneration

      Purpose : The purpose of this paper was to study type 1 macular neovascularization (MNV) quantitative optical coherence tomography (OCT) angiography (OCTA) features by means of advanced postprocessing analyses. Methods : We recruited patients affected by naïve type 1 MNV secondary to age-related macular degeneration (AMD) and age-matched controls. All patients underwent ophthalmologic examination and multimodal imaging. They were treated with pro-re-nata anti-VEGF injections. The ensuing follow-up lasted 24 months. Quantitative OCT and OCTA parameters were statistically analyzed to obtain cutoff values able to distinguish two clinically different patient subgroups. Main outcome measures were best-corrected visual acuity (BCVA), central macular thickness ...

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    23. Intradevice Repeatability and Interdevice Agreement of Ocular Biometric Measurements: A Comparison of Two Swept-Source Anterior Segment OCT Devices

      Intradevice Repeatability and Interdevice Agreement of Ocular Biometric Measurements: A Comparison of Two Swept-Source Anterior Segment OCT Devices

      Purpose : To assess the repeatability and agreement of ocular biometric parameters measured using the Tomey CASIA SS-1000 and Heidelberg ANTERION anterior segment optical coherence tomography (AS-OCT) devices. Methods : Both eyes of subjects 18 years of age or older were scanned three times with the CASIA and ANTERION under standardized dark lighting. One AS-OCT image along the horizontal (temporal-nasal) meridian was analyzed per eye and per scan. Pupillary diameter (PD) was within 15% for all pairwise comparisons. Anterior chamber depth, lens vault, anterior chamber width, angle opening distance, trabecular iris space area, and scleral spur angle (SSA500) were measured using manufacturer-provided ...

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    24. An Intelligent Optical Coherence Tomography-based System for Pathological Retinal Cases Identification and Urgent Referrals

      An Intelligent Optical Coherence Tomography-based System for Pathological Retinal Cases Identification and Urgent Referrals

      Purpose : This study aimed to develop an automated system with artificial intelligence algorithms to comprehensively identify pathologic retinal cases and make urgent referrals. Methods : To build and test the intelligent system, this study obtained 28,664 optical coherence tomography (OCT) images from 2254 patients in the Eye and ENT Hospital of Fudan University (EENT Hospital) and Shanghai Tenth People's Hospital (TENTH Hospital). We applied a deep learning model with an adapted feature pyramid network to detect 15 categories of retinal pathologies from OCT images as common signs of various retinal diseases. Subsequently, the pathologies detected in the OCT images ...

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