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    1. Noninvasive Estimation of Pulsatile and Static Intracranial Pressure by Optical Coherence Tomography

      Noninvasive Estimation of Pulsatile and Static Intracranial Pressure by Optical Coherence Tomography

      Purpose: To explore the ability of optical coherence tomography (OCT) to noninvasively estimate pulsatile and static intracranial pressure (ICP). Methods: An OCT examination was performed in patients who underwent continuous overnight monitoring of the pulsatile and static ICP for diagnostic purpose. We included two patient groups, patients with idiopathic intracranial hypertension (IIH; n = 20) and patients with no verified cerebrospinal fluid disturbances (reference; n = 12). Several OCT parameters were acquired using spectral-domain OCT (RS-3000 Advance; NIDEK, Singapore). The ICP measurements were obtained using a parenchymal sensor (Codman ICP MicroSensor; Johnson & Johnson, Raynham, MA, USA). The pulsatile ICP was determined as ...

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      Mentions: Nidek
    2. Lateral Resolution of a Commercial Optical Coherence Tomography Instrument

      Lateral Resolution of a Commercial Optical Coherence Tomography Instrument

      Purpose : The lateral resolution of an optical coherence tomography (OCT) instrument was considered to be equal to the illumination spot size on the retina. To evaluate the potential lateral resolution of the Spectralis OCT, an instrument calculated to have a 14 µm resolution. Methods : The lateral point spread function (PSF) was evaluated using diamond abrasive powder 0 to 1 µm in diameter in silicone elastomer and a validated target with 800 nm FeO particles in urethane. The amplitude transfer function was calculated from human OCT images. Finally, resolution was measured using the 1951 USAF target. Results : Measurement of the lateral ...

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    3. Assessment of Artifacts in Swept-Source Optical Coherence Tomography Angiography for Glaucomatous and Normal Eyes

      Assessment of Artifacts in Swept-Source Optical Coherence Tomography Angiography for Glaucomatous and Normal Eyes

      urpose: To evaluate the frequency of and identify the factors that influence the artifacts of swept-source optical coherence tomography angiography (SS-OCTA) in glaucomatous and normal eyes. Methods: Artifacts of OCTA images of open-angle glaucoma (OAG) and normal subjects were analyzed using SS-OCTA. Univariate and multivariate logistic regression analyses were performed to evaluate the association of age, sex, best-corrected visual acuity, axial length (AL), intraocular pressure, presence and severity of OAG, and image quality score (IQS) with the presence of artifacts. Results: Images from 4426 subjects were included in the study. At least one type of artifact was present in 24 ...

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    4. Progression of cRORA (Complete RPE and Outer Retinal Atrophy) in Dry Age-Related Macular Degeneration Measured Using SD-OCT

      Progression of cRORA (Complete RPE and Outer Retinal Atrophy) in Dry Age-Related Macular Degeneration Measured Using SD-OCT

      Purpose: The purpose of this study was to evaluate the long-term rate of progression and baseline predictors of geographic atrophy (GA) using complete retinal pigment epithelium and outer retinal atrophy (cRORA) annotation criteria. Methods: This is a retrospective study. Columns of GA were manually annotated by two graders using a self-developed software on optical coherence tomography (OCT) B-scans and projected onto the infrared images. The primary outcomes were: (1) rate of area progression, (2) rate of square root area progression, and (3) rate of radial progression towards the fovea. The effects of 11 additional baseline predictors on the primary outcomes ...

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    5. Diagnosis of Choroidal Disease With Deep Learning-Based Image Enhancement and Volumetric Quantification of Optical Coherence Tomography

      Diagnosis of Choroidal Disease With Deep Learning-Based Image Enhancement and Volumetric Quantification of Optical Coherence Tomography

      Purpose: The purpose of this study was to quantify choroidal vessels (CVs) in pathological eyes in three dimensions (3D) using optical coherence tomography (OCT) and a deep-learning analysis. Methods: A single-center retrospective study including 34 eyes of 34 patients (7 women and 27 men) with treatment-naïve central serous chorioretinopathy (CSC) and 33 eyes of 17 patients (7 women and 10 men) with Vogt-Koyanagi-Harada disease (VKH) or sympathetic ophthalmitis (SO) were imaged consecutively between October 2012 and May 2019 with a swept source OCT. Seventy-seven eyes of 39 age-matched volunteers (26 women and 13 men) with no sign of ocular ...

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    6. Retinal Microvascular Alterations Detected by Optical Coherence Tomography Angiography in Nonfunctioning Pituitary Adenomas

      Retinal Microvascular Alterations Detected by Optical Coherence Tomography Angiography in Nonfunctioning Pituitary Adenomas

      Purpose: Visual impairment assessment plays a significant role in diagnosis and clinical decisions in nonfunctioning pituitary adenoma (NFPA). Retinal microvascular alterations may potentially reflect the visual impairment. The purpose of this study was to evaluate fundus microvascular alterations in patients with NFPA. Methods: Comparisons of visual field, retinal structure, and microcirculation were conducted between patients with NFPA and age- and sex-matched healthy controls. Multivariate regression modeling was used to assess the relationship between symptom duration, sellar mass size, and fundus vessel density (VD) of patients. Receiver operating characteristic (ROC) curves were depicted to determine the diagnostic performance of significant parameters ...

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    7. Wide Corneal Epithelial Thickness Mapping in Eyes With Topical Antiglaucoma Therapy Using Optical Coherence Tomography

      Wide Corneal Epithelial Thickness Mapping in Eyes With Topical Antiglaucoma Therapy Using Optical Coherence Tomography

      Purpose: The purpose of this study was to assess the corneal epithelial thickness (CET) of the 9-mm diameter zone in patients treated using topical antiglaucoma medications and to evaluate the factors associated with CET changes. Methods: Seventy-five patients treated using topical antiglaucoma medications and 65 healthy subjects were included in this cross-sectional study. Each patient completed the Ocular Surface Disease Index (OSDI) questionnaire and underwent examinations including the Schirmer I test, tear breakup time (TBUT), and fluorescein staining. CET mapping of the 9-mm diameter zone was performed using RTVue XR. The CET of the different analyzed zones was compared between ...

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    8. OCT Assisted Quantification of Vitreous Inflammation in Uveitis

      OCT Assisted Quantification of Vitreous Inflammation in Uveitis

      Purpose: Vitreous haze (VH) is a key marker of inflammation in uveitis but limited by its subjectivity. Optical coherence tomography (OCT) has potential as an objective, noninvasive method for quantifying VH. We test the hypotheses that OCT can reliably quantify VH and the measurement is associated with slit-lamp based grading of VH. Methods: In this prospective study, participants underwent three repeated OCT macular scans to evaluate the within-eye reliability of the OCT vitreous intensity (VI). Association between OCT VI and clinical findings (including VH grade, phakic status, visual acuity [VA], anterior chamber cells, and macular thickness) were assessed. Results: One ...

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    9. Peripheral Chorioretinal Imaging Through a Front Prism on Optical Coherence Tomography Angiography

      Peripheral Chorioretinal Imaging Through a Front Prism on Optical Coherence Tomography Angiography

      Purpose: To evaluate the clinical feasibility of peripheral chorioretinal imaging through a front prism on swept-source optical coherence tomography angiography (SS-OCTA). Methods: We prospectively obtained en face OCTA images using SS-OCTA in 10 eyes of 10 healthy volunteers. For the peripheral chorioretinal imaging, the scanning laser passed and refracted through a 45°-90°-45° right-angle prism. We evaluated the qualitative and quantitative characteristics of chorioretinal vessels in the periphery. Results: Using peripheral chorioretinal imaging through a prism, the retinal vasculature was delineated to the equator on the OCTA images, and varices of the vortex vein ampullae were observed on choroidal ...

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    10. Conversion of Central Subfield Thickness Measurements of Diabetic Macular Edema Across Cirrus and Spectralis Optical Coherence Tomography Instruments

      Conversion of Central Subfield Thickness Measurements of Diabetic Macular Edema Across Cirrus and Spectralis Optical Coherence Tomography Instruments

      Purpose: Develop equations to convert Cirrus central subfield thickness (CST) to Spectralis CST equivalents and vice versa in eyes with diabetic macular edema (DME). Methods: The DRCR Retina Network Protocol O data were split randomly to train (70% sample) and validate (30% sample) conversion equations. Data from an independent study (CADME) also validated the equations. Bland-Altman 95% limits of agreement between predicted and observed values evaluated the equations. Results: Protocol O included 374 CST scan pairs from 187 eyes (107 participants). The CADME study included 150 scan pairs of 37 eyes (37 participants). Proposed conversion equations are Spectralis = 40.78 ...

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    11. Visualization of Anterior Chamber Angle Structures With Scattering- and Polarization-Sensitive Anterior Segment Optical Coherence Tomography

      Visualization of Anterior Chamber Angle Structures With Scattering- and Polarization-Sensitive Anterior Segment Optical Coherence Tomography

      Purpose: The purpose of this study was to compare three optical coherence tomography (OCT) modalities in the observation of anterior chamber angle structures; trabecular meshwork (TM), Schlemm's canal (SC), and band of extracanalicular limbal lamina (BELL). Methods: Three OCT modalities were used: (1) 2 × 2 Jones-matrix scattering OCT (S-OCT) representing conventional intensity OCT, (2) polarization-diverse S-OCT that was calculated as summation of all elements of the Jones-matrix to eliminate the influence of artifacts caused by sample birefringence, and (3) polarization-sensitive OCT (PS-OCT) to assess depth-resolved phase retardation. Results: In a total of 97 eyes of 55 subjects, nasal and ...

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    12. Plane-wave ultrasound assessment of ocular blood flow in preeclampsia and correlation with optical coherence tomography angiography

      Plane-wave ultrasound assessment of ocular blood flow in preeclampsia and correlation with optical coherence tomography angiography

      Purpose: Pre-eclampsia (PE) is a serious complication of pregnancy characterized by high blood pressure, proteinuria, compromised fetal blood supply, and potential organ damage. The superficial location of the eye makes it an ideal target for characterization hemodynamics. Our aim was to discern the impact of PE on ocular blood flow. Methods: 18 MHz plane-wave ophthalmic ultrasound scanning was performed on subjects with PE (n = 26), chronic or gestational hypertension (n = 8), and normal controls (n = 19) within 72 hours of delivery. Duplicate three-second long scans of the posterior pole including the optic nerve were acquired at 6000 images/sec for ...

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    13. Predicting 10-2 Visual Field From Optical Coherence Tomography in Glaucoma Using Deep Learning Corrected With 24-2/30-2 Visual Field

      Predicting 10-2 Visual Field From Optical Coherence Tomography in Glaucoma Using Deep Learning Corrected With 24-2/30-2 Visual Field

      Purpose: To investigate whether a correction based on a Humphrey field analyzer (HFA) 24-2/30-2 visual field (VF) can improve the prediction performance of a deep learning model to predict the HFA 10-2 VF test from macular optical coherence tomography (OCT) measurements. Methods: This is a multicenter, cross-sectional study. The training dataset comprised 493 eyes of 285 subjects (407, open-angle glaucoma [OAG]; 86, normative) who underwent HFA 10-2 testing and macular OCT. The independent testing dataset comprised 104 OAG eyes of 82 subjects who had undergone HFA 10-2 test, HFA 24-2/30-2 test, and macular OCT. A convolutional neural network ...

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    14. Advances in Imaging of Subbasal Corneal Nerves With Micro–Optical Coherence Tomography

      Advances in Imaging of Subbasal Corneal Nerves With Micro–Optical Coherence Tomography

      Purpose: To investigate the most peripheral corneal nerve plexus using high-resolution micro-optical coherence tomography (µOCT) imaging and to assess µOCT's clinical potential as a screening tool for corneal and systemic diseases. Methods: An experimental high-resolution (1.5 × 1.5 × 1 µm) µOCT setup was applied for three-dimensional imaging of the subbasal nerve plexus in nonhuman primates (NHPs) and swine within 3 hours postmortem. Morphologic features of subbasal nerves in µOCT were compared to β3 tubulin-stained fluorescence confocal microscopy (FCM). Parameters such as nerve density, nerve distribution, and imaging repeatability were evaluated, using semiautomatic image analysis in form of a ...

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    15. Prediction of Cardiovascular Parameters With Supervised Machine Learning From Singapore "I" Vessel Assessment and OCT-Angiography: A Pilot Study

      Prediction of Cardiovascular Parameters With Supervised Machine Learning From Singapore "I" Vessel Assessment and OCT-Angiography: A Pilot Study

      Purpose: Assessment of cardiovascular risk is the keystone of prevention in cardiovascular disease. The objective of this pilot study was to estimate the cardiovascular risk score (American Hospital Association [AHA] risk score, Syntax risk, and SCORE risk score) with machine learning (ML) model based on retinal vascular quantitative parameters. Methods: We proposed supervised ML algorithm to predict cardiovascular parameters in patients with cardiovascular diseases treated in Dijon University Hospital using quantitative retinal vascular characteristics measured with fundus photography and optical coherence tomography - angiography (OCT-A) scans (alone and combined). To describe retinal microvascular network, we used the Singapore "I" Vessel Assessment ...

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    16. Prevention of Image Quality Degradation in Wider Field Optical Coherence Tomography Angiography Images Via Image Averaging

      Prevention of Image Quality Degradation in Wider Field Optical Coherence Tomography Angiography Images Via Image Averaging

      Purpose: Assessment of cardiovascular risk is the keystone of prevention in cardiovascular disease. The objective of this pilot study was to estimate the cardiovascular risk score (American Hospital Association [AHA] risk score, Syntax risk, and SCORE risk score) with machine learning (ML) model based on retinal vascular quantitative parameters. Methods: We proposed supervised ML algorithm to predict cardiovascular parameters in patients with cardiovascular diseases treated in Dijon University Hospital using quantitative retinal vascular characteristics measured with fundus photography and optical coherence tomography - angiography (OCT-A) scans (alone and combined). To describe retinal microvascular network, we used the Singapore "I" Vessel Assessment ...

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    17. Automatic Screening and Identifying Myopic Maculopathy on Optical Coherence Tomography Images Using Deep Learning

      Automatic Screening and Identifying Myopic Maculopathy on Optical Coherence Tomography Images Using Deep Learning

      Purpose: The purpose of this study was to engineer deep learning (DL) models that can identify myopic maculopathy in patients with high myopia based on optical coherence tomography (OCT) images. Methods: An artificial intelligence (AI) system was developed using 2342 qualified OCT macular images from 1041 patients with pathologic myopia admitted to the Affiliated Eye Hospital of Wenzhou Medical University (WMU). We adopted an ResNeSt101 architecture to train five independent models to identify the following five myopic maculopathies: macular choroidal thinning, macular Bruch membrane (BM) defects, subretinal hyper-reflective material (SHRM), myopic traction maculopathy (MTM), and dome-shaped macula (DSM). We tested ...

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    18. A Hybrid Model Composed of Two Convolutional Neural Networks (CNNs) for Automatic Retinal Layer Segmentation of OCT Images in Retinitis Pigmentosa (RP)

      A Hybrid Model Composed of Two Convolutional Neural Networks (CNNs) for Automatic Retinal Layer Segmentation of OCT Images in Retinitis Pigmentosa (RP)

      Purpose: We propose and evaluate a hybrid model composed of two convolutional neural networks (CNNs) with different architectures for automatic segmentation of retina layers in spectral domain optical coherence tomography (SD-OCT) B-scans of retinitis pigmentosa (RP). Methods: The hybrid model consisted of a U-Net for initial semantic segmentation and a sliding-window (SW) CNN for refinement by correcting the segmentation errors of U-Net. The U-Net construction followed Ronneberger et al. (2015) with an input image size of 256 × 32. The SW model was similar to our previously reported approach. Training image patches were generated from 480 horizontal midline B-scans obtained from ...

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    19. Normative Data of Ocular Biometry, Optical Coherence Tomography, and Electrophysiology Conducted for Cynomolgus Macaque Monkeys

      Normative Data of Ocular Biometry, Optical Coherence Tomography, and Electrophysiology Conducted for Cynomolgus Macaque Monkeys

      Purpose: To present normative data of optical coherence tomography (OCT) parameters, electrophysiological tests, and optical biometry conducted for cynomolgus monkeys. Methods: Multimodal examinations were performed for 11 adult cynomolgus monkeys (Macaca fascicularis, weighing 2.6-7.5 kg, aged 45-99 months). A-scan biometry was performed to measure ocular biometry. OCT images were obtained at 30° and 55°. After the pupils were fully dilated, electroretinogram (ERG) and visual evoked potentials (VEP) were recorded with a commercial system using a contact lens electrode. Results: All cynomolgus monkeys were males. The mean axial length was 17.92 ± 0.34 mm. The central total retinal ...

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      Mentions: Korea University
    20. Automated Analysis of Choroidal Sublayer Morphologic Features in Myopic Children Using EDI-OCT by Deep Learning

      Automated Analysis of Choroidal Sublayer Morphologic Features in Myopic Children Using EDI-OCT by Deep Learning

      Purpose: The purpose of this study was to analyze the choroidal sublayer morphologic features in emmetropic and myopic children using an automatic segmentation model, and to explore the relationship between choroidal sublayers and spherical equivalent refraction (SER). Methods: We collected data on 92 healthy children (92 eyes) from the Ophthalmology Department of Peking University First Hospital. The data were allocated to three groups: emmetropia (+0.50 diopters [D] to -0.50 D), low myopia (-0.75 D to -3.00 D), and moderate myopia (-3.25 D to -5.75 D). We performed standardized optical coherence tomography (OCT) and developed ...

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    21. Challenges Associated With Ellipsoid Zone Intensity Measurements Using Optical Coherence Tomography

      Challenges Associated With Ellipsoid Zone Intensity Measurements Using Optical Coherence Tomography

      Optical coherence tomography (OCT) allows noninvasive visualization of individual retinal layers and has become a mainstay in the diagnosis and management of a wide range of retinal and systemic diseases. As the number of available treatments increases, there is growing interest in developing sensitive OCT-based biomarkers for assessing therapeutic response. In particular, the hyperreflective outer retinal band just posterior to the external limiting membrane, also known as the ellipsoid zone (EZ), is a widely used biomarker of photoreceptor structure. The integrity of the EZ, EZ lesion size, and width/area of retained EZ are established metrics that have been correlated ...

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    22. Topographic Variation of Retinal Vascular Density in Normal Eyes Using Optical Coherence Tomography Angiography

      Topographic Variation of Retinal Vascular Density in Normal Eyes Using Optical Coherence Tomography Angiography

      Purpose: To establish a continuous topography of retinal vessel density in normal eyes using optical coherence tomography angiography (OCTA). Methods: A retrospective chart review was performed, and 8-mm × 8-mm OCTA images from 22 normal eyes were analyzed. Vessel density was plotted as a continuous function of distance from the foveal center (radial vessel density) and directional meridians (directional vessel density) for the superficial capillary plexus and deep capillary plexus. Results: Continuous radial and directional vessel density plots for the superficial and deep capillary plexus were generated. Radial vessel density analysis revealed transition points at 657 microns (95% confidence interval [CI ...

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      Mentions: Yale University
    23. Region of Interest Densitometry Analysis of Descemet Membrane Endothelial Keratoplasty Dehiscence on Anterior Segment Optical Coherence Tomography

      Region of Interest Densitometry Analysis of Descemet Membrane Endothelial Keratoplasty Dehiscence on Anterior Segment Optical Coherence Tomography

      Purpose: To evaluate a region of interest (ROI) method of analyzing anterior segment optical coherence tomography (AS-OCT) corneal densitometry (CD) in the setting of Descemet membrane endothelial keratoplasty (DMEK) dehiscence. Methods: Retrospective chart review of eyes that underwent (1) DMEK for Fuchs dystrophy (2) between 2018 to 2020 with (3) a partial DMEK dehiscence on AS-OCT, (4) involvement of only one side of the graft, (5) high-quality corneal AS-OCT scan, and (6) location of dehiscence within the central 5.5 mm of the cornea. Image analysis of the ROIs with ImageJ compared the total edematous area, mean stromal CD, and ...

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    24. Enhanced Objective Detection of Retinal Nerve Fiber Bundle Defects in Glaucoma With a Novel Method for En Face OCT Slab Image Construction and Analysis

      Enhanced Objective Detection of Retinal Nerve Fiber Bundle Defects in Glaucoma With a Novel Method for En Face OCT Slab Image Construction and Analysis

      Purpose: To introduce and evaluate the performance in detecting glaucomatous abnormalities of a novel method for extracting en face slab images (SMAS), which considers varying individual anatomy and configuration of retinal nerve fiber bundles. Methods: Dense central retinal spectral domain optical coherence tomography scans were acquired in 16 participants with glaucoma and 19 age-similar controls. Slab images were generated by averaging reflectivity over different depths below the inner limiting membrane according to several methods. SMAS considered multiple 16 µm thick slabs from 8 to 116 µm below the inner limiting membrane, whereas 5 alternative methods considered single summary slabs of ...

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