1. Articles from Tae-Woo Kim

    1-24 of 27 1 2 »
    1. Evaluation of Peripapillary Choroidal Microvasculature to Detect Glaucomatous Damage in Eyes With High Myopia

      Evaluation of Peripapillary Choroidal Microvasculature to Detect Glaucomatous Damage in Eyes With High Myopia

      Precis: Parapapillary choroidal microvasculature dropout (MvD), as observed by optical coherence tomography (OCT) angiography, was useful to detect glaucomatous damage in highly myopic eyes with unreliable OCT results due to segmentation errors. Purpose: The purpose of this study was to evaluate the usefulness of optical coherence tomography angiography (OCTA) imaging of the peripapillary choroidal microvasculature in detecting glaucomatous damage in highly myopic eyes, in cases where evaluating the thickness of the retinal nerve fiber layer (RNFL) is unreliable due to OCT segmentation errors. Materials and Methods: Forty-five highly myopic eyes with primary open-angle glaucoma (POAG) with an axial length >26 ...

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    2. Pseudophakic Macular Edema in Primary Open-Angle Glaucoma: a Prospective Study Using Spectral-Domain Optical Coherence Tomography

      Pseudophakic Macular Edema in Primary Open-Angle Glaucoma: a Prospective Study Using Spectral-Domain Optical Coherence Tomography

      Purpose To determine the incidence of and risk factors for pseudophakic macular edema (PME) after uncomplicated cataract surgery in primary open-angle glaucoma (POAG) using spectral-domain optical coherence tomography (SD-OCT). Design Cohort study Methods Macular retinal thickness was evaluated using SD-OCT at 1-week before surgery and at 1-, 3-, 6-, and 12-months postoperatively, in 70 POAG and 68 control eyes. Forty-three healthy subjects without impaired vision or cystoid PME were recruited separately as pilot samples to define significant PME. Significant PME was defined as an increase in the average thickness exceeding the mean+three standard deviations of the increase shown in ...

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    3. Parapapillary Choroidal Microvasculature Dropout in Glaucoma A Comparison between Optical Coherence Tomography Angiography and Indocyanine Green Angiography

      Parapapillary Choroidal Microvasculature Dropout in Glaucoma  A Comparison between Optical Coherence Tomography Angiography and Indocyanine Green Angiography

      Purpose To investigate whether the parapapillary choroidal microvasculature dropout (MvD) determined by optical coherence tomography angiography (OCTA) in glaucomatous eyes indicates a true perfusion defect and whether the MvD accurately represents the area of nonperfusion. Design Observational case series. Participants Thirty primary open-angle glaucoma (POAG) patients with choroidal MvD as determined by OCTA and 13 POAG patients without this dropout. Methods Peripapillary circulation was evaluated using both OCTA and indocyanine green angiography (ICGA). For OCTA, the choroidal microvasculature was evaluated using 4.5×4.5-mm choroid–disc vessel density maps of OCTA images of the optic nerve head. An MvD ...

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    4. Underlying Microstructure of Parapapillary Deep-Layer Capillary Dropout Identified by Optical Coherence Tomography Angiography

      Underlying Microstructure of Parapapillary Deep-Layer Capillary Dropout Identified by Optical Coherence Tomography Angiography

      Purpose : To characterize the microstructure underlying the parapapillary deep-layer microvasculature dropout (MvD) identified by optical coherence tomography (OCT) angiography (OCTA) in eyes with primary open-angle glaucoma (POAG). Methods : Parapapillary MvD was defined as a focal sectoral capillary dropout without any visible microvascular network identified in deep-layer en face images obtained using swept-source OCTA. The peripapillary microstructure was characterized in 188 POAG patients with MvD in the parapapillary deep layer. Twelve radial optic nerve images were obtained using swept-source OCT to examine the peripapillary structure and measure the juxtapapillary choroidal thickness (JPCT). The JPCT was also measured in 72 age-matched POAG ...

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    5. Factors Associated with the Retinal Nerve Fiber Layer Loss after Acute Primary Angle Closure: A Prospective EDI-OCT Study

      Factors Associated with the Retinal Nerve Fiber Layer Loss after Acute Primary Angle Closure: A Prospective EDI-OCT Study

      Purpose To determine the factors associated with retinal nerve fiber layer (RNFL) loss in eyes with acute primary angle-closure (APAC), particularly focusing on the influence of the change in the anterior lamina cribrosa surface depth (LCD). Methods After the initial presentation, 30 eyes with unilateral APAC were followed up at the following specific time points over a 12-month period: 1 week, 1~2 months, 2~3 months, 5~6 months, and 11~12 months. These follow-ups involved intraocular pressure measurements, enhanced depth-imaging spectral-domain optical coherence tomography (SD-OCT) scanning of the optic disc, and measurements of the circumpapillary RNFL thickness. The ...

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    6. Retinal Nerve Fiber Layer Thickness Measurement Comparison Using Spectral Domain and Swept Source Optical Coherence Tomography

      Retinal Nerve Fiber Layer Thickness Measurement Comparison Using Spectral Domain and Swept Source Optical Coherence Tomography

      Purpose To investigate the retinal nerve fiber layer (RNFL) thickness concordance when measured by spectral domain (SD) and swept source (SS) optical coherence tomography (OCT), and to compare glaucoma-discriminating capability. Methods RNFL thicknesses were measured with the scan circle, centered on the optic nerve head, in 55 healthy, 41 glaucoma suspected, and 87 glaucomatous eyes. The RNFL thickness measured by the SD-OCT (sdRNFL thickness) and SS-OCT (ssRNFL thickness) were compared using the t -test. Bland-Altman analysis was performed to examine their agreement. We compared areas under the receiver operating characteristics curve and examined sdRNFL and ssRNFL thickness for discriminating glaucomatous ...

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    7. Comparison of the Abilities of SD-OCT and SS-OCT in Evaluating the Thickness of the Macular Inner Retinal Layer for Glaucoma Diagnosis

      Comparison of the Abilities of SD-OCT and SS-OCT in Evaluating the Thickness of the Macular Inner Retinal Layer for Glaucoma Diagnosis

      Purpose To compare the abilities of spectral-domain optical coherence tomography (OCT) (SD-OCT; Spectralis, Heidelberg Engineering) and swept-source OCT (SS-OCT; DRI-OCT1 Atlantis system, Topcon) for analyzing the macular inner retinal layers in diagnosing glaucoma. Methods The study included 60 patients with primary open-angle glaucoma (POAG) and 60 healthy control subjects. Macular cube area was scanned using SD-OCT and SS-OCT on the same day to assess the thicknesses of the macular retinal nerve fiber layer (mRNFL), ganglion cell layer plus inner plexiform layer (GCIPL), and total retinal layer in nine subfields defined by the Early Treatment Diabetic Retinopathy Study (ETDRS). The abilities ...

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    8. Differentiation of Parapapillary Atrophy Using Spectral-Domain Optical Coherence Tomography

      Differentiation of Parapapillary Atrophy Using Spectral-Domain Optical Coherence Tomography

      Purpose To develop a classification of parapapillary atrophy (PPA) based on its relationship with the location of Bruch's membrane (BM) termination in primary open-angle glaucoma (POAG) patients. Design Cross-sectional observational study. Participants This study analyzed 161 eyes from 161 POAG patients who had temporal β-zone PPA, the width of which was more than 200 μm on at least 1 horizontal scan image obtained by spectral-domain optical coherence tomography within the mid horizontal one third of the optic nerve. Methods Based on the extent of BM within the PPA area, eyes were categorized as group A (intact BM; 76 eyes ...

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    9. Diagnostic Ability of Spectral-domain Versus Time-domain Optical Coherence Tomography in Preperimetric Glaucoma

      Diagnostic Ability of Spectral-domain Versus Time-domain Optical Coherence Tomography in Preperimetric Glaucoma

      Purpose: To evaluate and compare the diagnostic abilities of the speckle noise-reduced spectral-domain optical coherence tomography (SD-OCT; Spectralis OCT) and time-domain optical coherence tomography (TD-OCT; Stratus OCT) to detect localized retinal nerve fiber layer (RNFL) defects in patients with preperimetric open-angle glaucoma. Methods: Thirty-five eyes of 35 preperimetric glaucoma patients with localized RNFL defects and 72 normal control eyes were scanned using SD-OCT and TD-OCT. Areas under the receiver-operating characteristic curves (AUROCs), and the sensitivity and specificity for detecting localized RNFL defects based on the internal normative database of each device were calculated and compared. Results: The AUROC for the ...

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    10. Improved Reproducibility in Measuring the Laminar Thickness on Enhanced Depth Imaging SD-OCT Images Using Maximum Intensity Projection

      Improved Reproducibility in Measuring the Laminar Thickness on Enhanced Depth Imaging SD-OCT Images Using Maximum Intensity Projection

      PURPOSE. To investigate whether the thin-slab maximum intensity projection (MIP) image improves the reproducibility of spectral domain optical coherence tomography (SD-OCT) based lamina cribrosa thickness (LCT) measurement. METHODS. Optic discs of 63 open angle glaucoma patients or glaucoma suspects were scanned with enhanced depth imaging SD-OCT. The B-scan images were constructed 3-dimensionally using MIP. The whole MIP volume was then cut into thin slabs of 2 scan-line distance width (approximately 64 μm) at 3 locations: mid-horizontal, and superior and inferior mid-peripheral regions of the optic nerve head. The LCT was measured in the thin-slab MIP images (LCT-MIP) and the 3 ...

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    11. Detection of Localized Retinal Nerve Fiber Layer Defects with Posterior Pole Asymmetry Analysis of Spectral-domain Optical Coherence Tomography

      Detection of Localized Retinal Nerve Fiber Layer Defects with Posterior Pole Asymmetry Analysis of Spectral-domain Optical Coherence Tomography

      Purpose:To investigate the diagnostic ability of posterior pole asymmetry analysis (PPAA) with spectral domain optical coherence tomography (Spectralis SD-OCT, Heidelberg Engineering, Heidelberg, Germany) for detecting localized retinal nerve fiber layer (RNFL) defects. Methods:Eighty-four open-angle glaucoma subjects (84 eyes) with localized, wedge-shape RNFL defects by red-free RNFL photography and 122 eyes of normal subjects were enrolled. The subjects were examined by SD-OCT to obtain circumpapillary RNFL (cpRNFL) thickness as well as PPAA. The PPAA provides a corresponding cell to cell comparison between hemispheres within the central 20° and presents the difference using gray scale. Area under the receiver operating ...

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    12. Three-Dimensional Evaluation of the Lamina Cribrosa Using Spectral-Domain Optical Coherence Tomography in Glaucoma

      Three-Dimensional Evaluation of the Lamina Cribrosa Using Spectral-Domain Optical Coherence Tomography in Glaucoma

      Purpose. To introduce a novel, digital, three-dimensional (3D) reconstruction of the optic nerve head (ONH) and to use this method to evaluate the 3D configuration of the lamina cribrosa (LC) in patients with primary open-angle glaucoma. Methods. Optic discs of 137 eyes of 137 patients with open-angle glaucoma were scanned with enhanced depth-imaging spectral domain-optical coherence tomography (SD-OCT). 3D images of the ONH were then reconstructed from B-scan images using maximum intensity projection (MIP) and texture-based volume rendering (VRT). The performance of the threshold segmentation by MIP and VRT was assessed by comparing the distance of the anterior LC surface ...

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    13. 3-Dimensional Evaluation of the Lamina Cribrosa Using Spectral Domain Optical Coherence Tomography in Glaucoma

      3-Dimensional Evaluation of the Lamina Cribrosa Using Spectral Domain Optical Coherence Tomography in Glaucoma
      Purpose: To introduce a novel, digital 3-dimensional (3D) reconstruction of the optic nerve head (ONH) and to evaluate the 3D configuration of the lamina cribrosa (LC) in patients with primary open angle glaucoma using this method. Methods: Optic discs of 137 eyes of 137 patients with open angle glaucoma were scanned with enhanced depth imaging spectral domain-optical coherence tomography (SD-OCT). 3D images of the ONH then were reconstructed from B scan images using maximum intensity projection (MIP) and texture based-volume rendering (VRT). The performance of the threshold segmentation by MIP and VRT was assessed by comparing the distance of the ...
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    14. Diagnostic Accuracy of OCT with a Normative Database to Detect Diffuse Retinal Nerve Fiber Layer Atrophy: Diffuse Atrophy Imaging Study

      Diagnostic Accuracy of OCT with a Normative Database to Detect Diffuse Retinal Nerve Fiber Layer Atrophy: Diffuse Atrophy Imaging Study

      Purpose: To investigate the diagnostic accuracy of Stratus optical coherence tomography (OCT) with its internal normative database to detect diffuse retinal nerve fiber layer (RNFL) atrophy in glaucoma subjects. Methods: One hundred two eyes of 102 glaucoma patients with diffuse RNFL atrophy and 102 healthy eyes of 102 age-matched subjects were enrolled in the Diffuse Atrophy Imaging Study. Two experienced observers graded RNFL photographs of diffuse RNFL atrophy eyes using a four-level grading system. The diagnostic performances for detecting diffuse RNFL atrophy were examined according to the visual field results as well as the RNFL photographs grading. Results: Using a ...

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    15. Glaucoma Progression After the First-detected Optic Disc Hemorrhage by Optical Coherence Tomography

      Glaucoma Progression After the First-detected Optic Disc Hemorrhage by Optical Coherence Tomography

      Purpose: To evaluate the progression of glaucoma after first detected disc hemorrhage (DH) by time-domain optical coherence tomography (OCT). Methods: Forty-four eyes with a unilateral DH were allocated to the DH group and 44 fellow eyes to the non-DH group. OCT signal decrease indicating retinal nerve fiber layer thinning was defined as a decrease beyond the upper 95% limit of test-retest variability defined at the 95% confidence level of 44 control patients. The DH and non-DH groups were compared in terms of OCT-derived glaucoma progressions after the first detected DH. In addition, clock-hour locations of the OCT-derived progression were compared ...

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    16. Visualization of the Lamina Cribrosa Using Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography

      Visualization of the Lamina Cribrosa Using Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography

      Purpose To investigate whether the enhanced depth imaging technique (EDI) may improve the visualization of the lamina cribrosa using spectral-domain optical coherence tomography (SD-OCT). Design Prospective observational case series. Methods Images of the optic nerve were obtained in 10 normal subjects, 7 glaucoma suspects, and 18 glaucoma patients by positioning an SD-OCT in the usual fashion, as well as close enough to the eye to obtain an inverted representation of the fundus (EDI). In addition to these single line scans, approximately 65 sections were obtained within a 10 × 15-degree rectangle covering the optic nerve head using EDI. The “depth of ...

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    17. Changes in Anterior Chamber Configuration after Cataract Surgery as Measured by Anterior Segment Optical Coherence Tomography

      Changes in Anterior Chamber Configuration after Cataract Surgery as Measured by Anterior Segment Optical Coherence Tomography

      Purpose To evaluate the changes in anterior chamber depth (ACD) and angle width induced by phacoemulsification and intraocular lens (IOL) implantation in normal eyes using anterior segment optical coherence tomography (AS-OCT). Methods Forty-five eyes (45 patients) underwent AS-OCT imaging to evaluate anterior chamber configuration before and 2 days after phacoemulsification and IOL implantation. We analyzed the central ACD and angle width using different methods: anterior chamber angle (ACA), trabecular-iris angle (TIA), angle opening distance (AOD), and trabecular iris surface area (TISA) in the nasal and temporal quadrants. Comparison between preoperative and postoperative measurement was done using paired t-tests and each ...

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    18. Trend-based Analysis of Retinal Nerve Fiber Layer Thickness Measured by Optical Coherence Tomography in Eyes with Localized Nerve Fiber Layer Defects

      Trend-based Analysis of Retinal Nerve Fiber Layer Thickness Measured by Optical Coherence Tomography in Eyes with Localized Nerve Fiber Layer Defects
      Purpose. To evaluate the rate of change in retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) in eyes with stable and progressive localized RNFL defects, and to investigate the diagnostic capability of OCT in the detection of progressive RNFL thinning using a trend-based approach. Methods. The study included 153 glaucomatous eyes with localized RNFL defects. Patients were divided into nonprogressors (n=77) and progressors (n=76), based on evaluation of serial red-free photographs. The rates of progressive thinning in global, quadrant, and clock-hour OCT RNFL thicknesses were determined using linear regression and compared between groups. Areas ...
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    19. Quantitative Assessment of Diffuse Retinal Nerve Fiber Layer Atrophy Using Optical Coherence Tomography: Diffuse Atrophy Imaging Study

      Quantitative Assessment of Diffuse Retinal Nerve Fiber Layer Atrophy Using Optical Coherence Tomography: Diffuse Atrophy Imaging Study

      Purpose To evaluate quantitatively the degree of diffuse retinal nerve fiber layer (RNFL) atrophy using Stratus optical coherence tomography (OCT). Design Prospective, cross-sectional study. Participants One hundred two eyes of 102 patients with diffuse RNFL atrophy and 102 healthy eyes of 102 age-matched subjects were enrolled in the Diffuse Atrophy Imaging Study. Methods Two experienced observers graded RNFL photographs of diffuse RNFL atrophy eyes using a previously reported standardized protocol with a 4-level grading system. Readings were taken from the superior and inferior RNFL areas. The OCT-measured RNFL thickness parameters were compared among normal eyes and diffuse atrophy subgroups. Area ...

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    20. Quantitative Assessment of Diffuse Retinal Nerve Fiber Layer Atrophy Using Optical Coherence Tomography: Diffuse Atrophy Imaging Study

      Quantitative Assessment of Diffuse Retinal Nerve Fiber Layer Atrophy Using Optical Coherence Tomography: Diffuse Atrophy Imaging Study

      Purpose: To evaluate quantitatively the degree of diffuse retinal nerve fiber layer (RNFL) atrophy using Stratus optical coherence tomography (OCT).Design: Prospective, cross-sectional study.Participants: One hundred two eyes of 102 patients with diffuse RNFL atrophy and 102 healthy eyes of 102 age-matched subjects were enrolled in the Diffuse Atrophy Imaging Study.Methods: Two experienced observers graded RNFL photographs of diffuse RNFL atrophy eyes using a previously reported standardized protocol with a 4-level grading system. Readings were taken from the superior and inferior RNFL areas. The OCT-measured RNFL thickness parameters were compared among normal eyes and diffuse atrophy subgroups. Area ...

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    21. Reproducibility of Retinal Nerve Fiber Thickness Measurements Using the Test-retest Function of Spectral OCT/SLO in Normal and Glaucomatous Eyes

      Purpose: To evaluate the reproducibility of retinal nerve fiber layer (RNFL) thickness measurements in normal and glaucoma patients using the spectral optical coherence tomography (OCT)/scanning laser ophthalmosope (SLO). Methods: One experienced operator measured peripapillary RNFL thickness 3 times in succession in 98 normal participants and 79 glaucoma patients by using the test-retest function of the spectral OCT/SLO. The intraclass correlation coefficient (ICC), coefficient of variation, and test-retest variability (TRV) were analyzed for the mean RNFL thickness, and the RNFL thickness in each quadrant and at each clock-hour, in randomly selected eyes. The correlation coefficient was calculated between the ...

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    22. Peripapillary Retinal Nerve Fiber Layer Thickness Profile in Subjects with Myopia Measured Using the Stratus Optical Coherence Tomography

      Background/aims: To evaluate the relationship between the axial length and refractive error and peripapillary retinal nerve fiber layer(RNFL) thickness profiles measured using the Stratus optical coherence tomography(OCT) in subjects with myopia. Methods: Forty-eight eyes of 48 myopic subjects were recruited and divided into three groups according to their spherical equivalent(SE):low (- 3.0 D < SE < 0.0 D), moderate (-6.0 D < SE ≤ -3.0 D) and high (SE ≤ -6.0 D) myopia groups. All individuals underwent the imaging with the Stratus OCT.The RNFL thickness profiles were compared between the groups. Results: The global average ...
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    23. Ability of Stratus OCT to Detect Progressive Retinal Never Fiber Layer Atrophy in Glaucoma

      PURPOSE. To evaluate the ability of Stratus optical coherence tomography (OCT) to detect progressive glaucomatous retinal nerve fiber layer (RNFL) atrophy observed using red-free RNFL photography. METHODS. Intersession test-retest variability of each clock hour, quadrant, and average RNFL thickness was determined using 53 control subjects. The sensitivity and specificity of OCT for identification of progressive RNFL atrophy were tested on subjects in whom this condition was clearly observed in red-free RNFL photographs (n=27) and in another control group (n=62) using criteria derived from test-retest variability. RESULTS. The sensitivity of Stratus OCT RNFL measurement ranged from 14.8% (for ...

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    24. Optic Disc Hemorrhage May Be Associated with Retinal Nerve Fiber Loss in Otherwise Normal Eyes

      Purpose: To evaluate quantitatively the structural damage of the peripapillary retinal nerve fiber layer (RNFL) in eyes with disc hemorrhage (DH).Design: Prospective cross-sectional study.Participants: Seventy patients with DH (70 eyes; mean age ± standard deviation, 60.0±11.8 years) and 100 healthy control subjects (100 eyes; mean age ± standard deviation, 57.7±8.0 years) were enrolled from the Glaucoma Clinic of Seoul National University Hospital.Methods: Normal eyes without DH (group 1: normal control group) served as controls. Eyes with DH were divided into the following groups: (1) eyes with a DH, accompanied by no visible RNFL ...

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    1. (25 articles) Seoul National University
    2. (24 articles) Tae-Woo Kim
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    Changes in Anterior Chamber Configuration after Cataract Surgery as Measured by Anterior Segment Optical Coherence Tomography Visualization of the Lamina Cribrosa Using Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography Diagnostic Accuracy of OCT with a Normative Database to Detect Diffuse Retinal Nerve Fiber Layer Atrophy: Diffuse Atrophy Imaging Study Glaucoma Progression After the First-detected Optic Disc Hemorrhage by Optical Coherence Tomography Optical Coherence Tomography: Critical Tool to Manage Expectations after Cataract Extraction Improving the characterization of ex vivo human brain optical properties using high numerical aperture optical coherence tomography by spatially constraining the confocal parameters Choroidal, macular and ganglion cell layer thickness assessment in Caucasian children measured with spectral domain optical coherence tomography Examination of retinal vascular density changes via optical coherence tomography angiography in patients with glaucoma 3D reconstruction of coronary artery bifurcations from coronary angiography and optical coherence tomography: feasibility, validation, and reproducibility Age- and refraction-related changes in anterior segment anatomical structures measured by swept-source anterior segment OCT The evaluation of juvenile ocular hypertension by optical coherence tomography angiography Superficial capillary perfusion on optical coherence tomography angiography differentiates moderate and severe nonproliferative diabetic retinopathy