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    1. Longitudinal Detection of Radiation-Induced Peripapillary and Macular Retinal Capillary Ischemia Using Optical Coherence Tomography Angiography

      Longitudinal Detection of Radiation-Induced Peripapillary and Macular Retinal Capillary Ischemia Using Optical Coherence Tomography Angiography

      Purpose To study longitudinal changes in retinal capillary circulation in eyes treated with iodine 125 (I-125) plaque brachytherapy for uveal melanoma using optical coherence tomography angiography (OCTA). Design Longitudinal prospective study of 21 subjects undergoing treatment for uveal melanoma with I-125 plaque brachytherapy. Eyes with melanoma were imaged with OCTA prior to treatment and at 12 month intervals until 2 years post-brachytherapy. Participants After IRB-approval, participants were enrolled prospectively from an academic ocular oncology clinic. Patients with low vision of < 20/200 in the eye with tumor at baseline were excluded. Methods Peripapillary (4.5 x 4.5-mm) and macular ...

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    2. Morphometric characteristics of the optical disc and thickness of retinal nerve fibre layer using Cirrus 5000 optical coherence tomography in healthy patients attending the National Institute of Ophthalmology

      Morphometric characteristics of the optical disc and thickness of retinal nerve fibre layer using Cirrus 5000 optical coherence tomography in healthy patients attending the National Institute of Ophthalmology

      Objective To describe the morphometric characteristics and thickness of the retinal nerve fibre layer (CFNR) in healthy patients using optical coherence tomography. Methods A cross-sectional and descriptive study was conducted on a total of 184 eyes of 184 people of mestizo origin enrolled after a complete ophthalmological evaluation at the National Institute of Ophthalmology, Lima-Peru. The morphometric parameters of the optic disc and thickness of the CFNR were measured by optical coherence tomography ZEISS CIRRUS™ HD-OCT Model 5000 (Carl Zeiss Inc., Dublin, CA, EE.UU). Megalopapilla was defined as: area of the optical disc greater than 2.5 mm 2 ...

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    3. Automated detection of glaucoma using optical coherence tomography angiogram images

      Automated detection of glaucoma using optical coherence tomography angiogram images

      Glaucoma is a malady that occurs due to the buildup of fluid pressure in the inner eye. Detection of glaucoma at an early stage is crucial as by 2040, 111.8 million people are expected to be afflicted with glaucoma globally. Feature extraction methods prove to be promising in the diagnosis of glaucoma. In this study, we have used optical coherence tomography angiogram (OCTA) images for automated glaucoma detection. Ocular sinister (OS) from the left eye while ocular dexter (OD) were obtained from right eye of subjects. We have used OS macular, OS disc, OD macular and OD disc images ...

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    4. Efficient supercontinuum generation enabled by dispersion engineering in a dual-core waveguide

      Efficient supercontinuum generation enabled by dispersion engineering in a dual-core waveguide

      A compact dual-core waveguide is proposed for efficient supercontinuum generation, in which the use of Si-rich nitride and titanium dioxide provides a large enough index contrast for dispersion engineering. Strong anomalous group velocity dispersion is obtained over a wide bandwidth of 1860 nm which greatly reduces the dispersion length. The nonlinear length can also be significantly decreased due to high nonlinear Kerr index of Si-rich nitride. As a consequence, it could facilitate octave-spanning supercontinuum generation from 1160 to 2385 nm in a greatly reduced propagation distance, as short as 165μm . It is more than one order of magnitude shorter ...

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    5. Deep Learning Approaches Predict Glaucomatous Visual Field Damage from Optical Coherence Tomography Optic Nerve Head Enface Images and Retinal Nerve Fiber Layer Thickness Maps

      Deep Learning Approaches Predict Glaucomatous Visual Field Damage from Optical Coherence Tomography Optic Nerve Head Enface Images and Retinal Nerve Fiber Layer Thickness Maps

      Purpose To develop and evaluate a deep learning system for differentiating between eyes with and without glaucomatous visual field damage (GVFD) and predicting the severity of GFVD from spectral domain optical coherence tomography (SDOCT) optic nerve head images. Design Evaluation of a diagnostic technology Participants 9,765 visual field (VF)–SDOCT pairs collected from 1,194 participants with and without GVFD (1909 eyes). Methods Deep learning models were trained to use SDOCT retinal nerve fiber layer (RNFL) thickness maps, RNFL enface images, and confocal scanning laser ophthalmoscopy (CSLO) images to identify eyes with GVFD and predict quantitative VF mean deviation ...

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    6. Geographic Atrophy Segmentation in SD-OCT Images Using Synthesized Fundus Autofluorescence Imaging

      Geographic Atrophy Segmentation in SD-OCT Images Using Synthesized Fundus Autofluorescence Imaging

      Background and Objective Accurate assessment of geographic atrophy (GA) is critical for diagnosis and therapy of non-exudative age-related macular degeneration (AMD). Herein, we propose a novel GA segmentation framework for spectral-domain optical coherence tomography (SD-OCT) images that employs synthesized fundus autofluorescence (FAF) images. Methods An en-face OCT image is created via the restricted sub-volume projection of three-dimensional OCT data. A GA region-aware conditional generative adversarial network is employed to generate a plausible FAF image from the en-face OCT image. The network balances the consistency between the entire synthesize FAF image and the lesion. We use a fully convolutional deep network ...

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    7. Choroidal thickness profile in normal Iranian eyes with different refractive status by spectral-domain optical coherence tomography

      Choroidal thickness profile in normal Iranian eyes with different refractive status by spectral-domain optical coherence tomography

      Purpose To investigate the choroidal thickness and its association with age, gender, spherical equivalent (SE), and axial length (AL) in a sample of Iranian population with different refractive status using spectral-domain optical coherence tomography (SD-OCT). Methods In a cross-sectional study, a total of 469 right eyes of 469 healthy subjects comprising 194 (41.4%) males and 275 (58.6%) females were examined. The mean age was 32.76 ± 15.77 years (range, 4–60 years). All subjects were divided into different groups according to their refractive status, age, and AL. The choroidal thickness was evaluated through enhanced-depth imaging (EDI) modality ...

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    8. Correlation between cognitive impairment and retinal neural loss assessed by swept-source optical coherence tomography in patients with mild cognitive impairment

      Correlation between cognitive impairment and retinal neural loss assessed by swept-source optical coherence tomography in patients with mild cognitive impairment

      Introduction We compared peripapillary retinal nerve fiber layer and macular thickness measurements in patients with mild cognitive impairment (MCI) and control subjects using swept-source optical coherence tomography (SS-OCT). We also assessed the relationship between SS-OCT measurements and the severity of cognitive impairment. Methods Peripapillary retinal nerve fiber layer and macular thickness were measured in 23 patients and 24 control subjects using SS-OCT. Cognitive status was assessed using the Mini-Mental State Examination, the Montreal Cognitive Assessment, and the Pfeffer Questionnaire. Results Most inner retinal layer thickness parameters were significantly smaller in patients with MCI, especially macular ganglion cell complex thickness measurements ...

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    9. Microaneurysm Imaging using Multiple En Face Optical Coherence Tomography Angiography Image Averaging: Morphology and Visualization

      Microaneurysm Imaging using Multiple En Face Optical Coherence Tomography Angiography Image Averaging: Morphology and Visualization

      Purpose In diabetic retinopathy (DR), optical coherence tomography angiography (OCTA) could not image all fluorescein angiography (FA)-detected microaneurysms. We investigated if multiple image averaging could enhance its microaneurysm detection capability in DR. Design Prospective- and cross-sectional observational study. Participants Consecutive 31 patients (n = 62 eyes) with DR. Methods All eyes underwent FA, and 3 x 3 mm fovea-centered OCTA images were obtained using two devices (RTVue XR Avanti: Optovue Inc. and OCT HS-100: Canon Inc.). OCTA imaging (HS-100) was performed ten consecutive times. Microaneurysm detection capability was compared among five OCTA images (single image, 3x, 5x, and 10x averaged ...

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    10. Automated segmentation of fluid regions in optical coherence tomography B-scan images of age-related macular degeneration

      Automated segmentation of fluid regions in optical coherence tomography B-scan images of age-related macular degeneration

      Age-related macular degeneration (AMD) is a common eye disease that causes progressive vision loss in people older than 50 years. Fluid regions in retina are the most characteristic of AMD. Accurately segmenting fluid regions is crucial for the early diagnosis of AMD, and assessment of treatment efficacy. In this paper, we propose an automatic deep learning method constructed by integrating Squeeze-and-Excitation blocks with U-Net named SEUNet to segment fluid regions and classify OCT B-scan images to AMD or normal image. The proposed method comprises three stages: (1) preprocessing stage that includes image noise removal, locating the image on the area ...

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    11. Optical biopsy of penile cancer with in vivo confocal laser endomicroscopy

      Optical biopsy of penile cancer with in vivo confocal laser endomicroscopy

      Introduction Surgical management of penile cancer depends on accurate margin assessment and staging. Advanced optical imaging technologies may improve penile biopsy and organ-sparing treatment. We evaluated the feasibility of confocal laser endomicroscopy for intraoperative assessment of benign and malignant penile tissue. Patients and methods With institutional review board approval, 11 patients were recruited, 9 with suspected penile cancer, and 2 healthy controls. Confocal laser endomicroscopy using a 2.6-mm fiber-optic probe was performed at 1 or 2 procedures on all subjects, for 13 imaging procedures. Fluorescein was administered intravenously approximately 3 minutes prior to imaging for contrast. Video sequences from ...

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    12. Effect of night work on image quality of optical coherence tomography angiography

      Effect of night work on image quality of optical coherence tomography angiography

      Purpose To assess the effect of night shift work on image quality and artifacts when performing optical coherence tomography angiography (OCT-A). Methods In a prospective case series study, twenty nurses underwent OCT-A in two separate sessions: early in the morning before duty shift and at the end of a night shift. Quantitative measurements of horizontal and vertical saccadic, blink, and stretch artifacts and also signal strength of the images were recorded. Moreover, using visual analogue scale of pain (VAS), the perceived pain and discomfort by blue focus light and red scanning laser were recorded. Results Vertical and horizontal saccades, blink ...

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    13. Automated quantification of choroidal neovascularization on Optical Coherence Tomography Angiography images

      Automated quantification of choroidal neovascularization on Optical Coherence Tomography Angiography images

      Objectives To report the design of an automated quantification algorithm for choroidal neovascularization (CNV) in the context of neovascular age-related macular degeneration (AMD), based on Optical Coherence Tomography Angiography (OCTA) images. Material and methods In this study, 54 patients (mean age 75.80 ± 14.29 years) with neovascular AMD (type 1 and type 2 CNV) were included retrospectively and separated into two groups (Group 1–24 images; Group 2–30 images), according to the lesion topology. All patients underwent a 3 × 3 mm OCTA examination (AngioVue, Optovue, Freemont, California). The proposed algorithm is based on segmentation and enhancement methods including ...

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    14. Subintimal Versus Intraplaque Recanalization of Coronary Chronic Total Occlusions: Mid-Term Angiographic and OCT Findings From the ISAR-OCT-CTO Registry

      Subintimal Versus Intraplaque Recanalization of Coronary Chronic Total Occlusions: Mid-Term Angiographic and OCT Findings From the ISAR-OCT-CTO Registry

      Objectives The aim of this study was to compare angiographic and optical coherence tomography findings following subintimal as opposed to intraplaque recanalization of chronic total occlusions (CTOs). Background There is ongoing controversy regarding outcomes of intraplaque versus subintimal CTO recanalization. Methods Consecutive patients undergoing angiography and intravascular optical coherence tomography following CTO recanalization were included in the ISAR-OCT-CTO (Intracoronary Stenting and Angiographic Results - Optical Coherence Tomography for Chronic Total Occlusions) registry. The study endpoints were percent diameter stenosis and late lumen loss as well as rate of uncovered and malapposed struts. Independent correlates of uncovered and malapposed struts were assessed ...

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    15. Objective evaluation of proliferative diabetic retinopathy using optical coherence tomography

      Objective evaluation of proliferative diabetic retinopathy using optical coherence tomography

      Purpose To present the routine use of optical coherence tomography (OCT) and OCT angiography (OCTA) for the objective diagnosis and monitoring of proliferative diabetic retinopathy (PDR). Design Retrospective observational case series. Subjects Patients with diabetic retinopathy imaged using a standardized PDR-protocol Methods Patients routinely imaged with a standardized PDR-protocol between March 2017 and January 2019 were included. This included a 12x9 mm structural OCT volume centered on the macula and a 6x6 mm OCTA scan centered on the optic nerve head obtained using a Topcon swept-source system (DRI OCT-1 Triton, Topcon, Tokyo, Japan). Ultra-widefield fluorescein angiography (FA) was also performed ...

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    16. Optical coherence tomography diagnostic signs in posterior uveitis

      Optical coherence tomography diagnostic signs in posterior uveitis

      A diagnostic sign refers to a quantifiable biological parameter that is measured and evaluated as an indicator of normal biological, pathogenic, or pharmacologic responses to a therapeutic intervention. When used in translational research discussions, the term itself often alludes to a signs used to accelerate or aid in diagnosis or monitoring and provide insight into “personalized” medicine. Many new diagnostic signs are being developed that involve imaging technology. Optical coherence tomography is an imaging technique that provides in vivo quasi-histological images of the ocular tissues and as such it's able to capture the structural and functional modifications that accompany ...

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    17. Optical coherence tomography en face analysis of the posterior vitreous reveal topographic relationships between premacular bursa, prevascular fissures and cisterns

      Optical coherence tomography en face analysis of the posterior vitreous reveal topographic relationships between premacular bursa, prevascular fissures and cisterns

      Purpose To characterize the topographic relationships among vitreous structures including the premacular bursa, prevascular vitreous fissures, cisterns and lacunae in healthy subjects using en face and cross-sectional swept-source optical coherence tomography (SS-OCT). Design Prospective comparative study. Subjects Sixty eyes of 60 healthy subjects (age range = 4 – 35 years). Eyes of individuals younger than 20 years (n= 29) were compared with eyes of individuals aged 20 years or older (n=31). Testing Twelve x 12-mm SS-OCT volume scans comprised of 1024 x 1024 A-scans centered at the fovea were acquired from each study eye. Main Outcome Measures En face and cross-sectional ...

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    18. Effect of evolocumab therapy on coronary fibrous cap thickness assessed by optical coherence tomography in patients with acute coronary syndrome

      Effect of evolocumab therapy on coronary fibrous cap thickness assessed by optical coherence tomography in patients with acute coronary syndrome

      Background The addition of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor, evolocumab, to statin therapy produced incremental regression of atherosclerotic plaques and a collaborative prevention of cardiovascular events in patients with coronary artery disease. The effect on fibrous-cup thickness, or extension of the atherosclerotic plaque with PCSK9-inhibitor, for several weeks after onset of acute coronary syndrome (ACS) has never been reported. Methods This study aimed to examine the effect of evolocumab on fibrous-cap thickness, as well as the extent of the atherosclerotic plaque, by serial optical coherence tomography (OCT) analysis in patients with ACS. All patients received rosuvastatin 5 ...

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    19. Intracoronary pressure increase due to contrast injection for optical coherence tomography imaging

      Intracoronary pressure increase due to contrast injection for optical coherence tomography imaging

      Background Optical coherence tomography (OCT) requires intracoronary injection of contrast media to remove blood from the field of view during image acquisition. Contrast injection may cause a temporal increase in intracoronary pressure. The aim of this study was to compare the intracoronary pressure during contrast injection between OCT and coronary angiography . Methods We measured intracoronary pressure by using a pressure guidewire during contrast injection for OCT and angiography in 30 coronary arteries (mean fractional flow reserve = 0.90 ± 0.03). Contrast media was injected into coronary artery through the guiding catheter by using a mechanical injector pump. Results Intracoronary pressure ...

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    20. Swept Source Optical Coherence Tomography Analysis of the Margin of Choroidal Coloboma : New Insights

      Swept Source Optical Coherence Tomography Analysis of the Margin of Choroidal Coloboma : New Insights

      Purpose To study the retinal architecture and vitreo-retinal interface at the edge of choroidal colobomata using swept source optical coherence tomography (SS-OCT). Design: Prospective observational case series at a tertiary eye care center. Participants Patients of choroidal coloboma presenting to ophthalmology department and fulfilling the inclusion criteria of the study. Testing SS-OCT was done in 30 eyes of 20 patients of choroidal coloboma. Main Outcome Measures The primary objective was to describe the OCT features at the margin of coloboma. Results SS-OCT of the coloboma margin revealed new features in addition to the previously described findings. Two types of transition ...

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    21. DN-GAN: Denoising generative adversarial networks for speckle noise reduction in optical coherence tomography images

      DN-GAN: Denoising generative adversarial networks for speckle noise reduction in optical coherence tomography images

      Optical coherence tomography (OCT) is an efficient noninvasive bioimaging technique that can measure retinal tissue. Considering the changes in the acquisition environment during imaging, the OCT images are affected by granular speckle noise, thereby reducing the image quality. In this paper, an efficient method based on generative adversarial network is proposed to reduce the speckle noise and preserve the texture details. The proposed model consists of two components, that is, a denoising generator and a discriminator. The denoising generator learns how to map the noise image to the ground truth. The discriminator learns as a loss function to compare the ...

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    22. Deep learning based early stage diabetic retinopathy detection using optical coherence tomography

      Deep learning based early stage diabetic retinopathy detection using optical coherence tomography

      Diabetic retinopathy (DR) is one of the leading causes of preventable blindness globally. Performing retinal examinations on all diabetic patients is an unmet need, and detection at an early stage can provide better control of the disease. The objective of this study is to provide an optical coherence tomography (OCT) image based diagnostic technology for automated early DR diagnosis, including at both grades 0 and 1. This work can help ophthalmologists with evaluation and treatment, reducing the rate of vision loss, and enabling timely and accurate diagnosis. In this work, we developed and evaluated a novel deep network – OCTD_Net, for ...

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    23. Spectral-Domain Optical Coherence Tomography for the Non-Invasive Investigation of the Pigment Layers of Tang Dynasty Tomb Murals Exhibited in Museums

      Spectral-Domain Optical Coherence Tomography for the Non-Invasive Investigation of the Pigment Layers of Tang Dynasty Tomb Murals Exhibited in Museums

      Optical coherence tomography (OCT) is a non-invasive subsurface three-dimensional imaging technique based on the Michelson interferometer. Due to the nature of non-invasive detection and high-speed acquisition, OCT is efficient for imaging intact objects to generate a complete overview of their microstructure. This paper presents the investigation of the pigment layer and ground layer of three Tang dynasty tomb murals exhibited in museums with Spectral-domain optical coherence tomography (SD-OCT). The investigation results demonstrated that SD-OCT system can obtain clear images of the subsurface microstructure and preservation status of ancient murals and can precisely locate and measure the location of the mural ...

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    24. Epithelial tissue thickness improves optical coherence tomography’s ability in detecting oral cancer

      Epithelial tissue thickness improves optical coherence tomography’s ability in detecting oral cancer

      Background OCT is a non-invasive imaging technique that enables the measurement of epithelial thickness and architectural changes, which can help in the diagnosis of pre-cancerous and cancerous lesions. The purpose of the study was to assess whether epithelial tissue thickness improves optical coherence tomography’s ability in detecting oral cancer. Patients and Methods Surgically resected oral margins from 60 patients diagnosed with oral squamous cell carcinoma were subjected to OCT. Three OCT measurements (immediate, 1 hour and 24 hours post-resection) were conducted per resected tissue specimen to look at the effect of saline and formalin on the specimen and its ...

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