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    1. Measurement of macular structure-function relationships using spectral domain-optical coherence ...

      Measurement of macular structure-function relationships using spectral domain-optical coherence ...

      Background Retinal ganglion cell (RGC) death is a common cause of loss of vision during glaucoma. Pattern electroretinogram (PERG) is an objective measure of the central retinal function that correlates with macular GCL thickness. The aim of this study is to determine possible relationships between the N95 amplitude of pattern electroretinogram (PERG amp ) and macular ganglion cell/inner plexiform layer thickness (GCIPLT). Methods and findings This was a retrospective and comparative study including 74 glaucoma patients (44 early stage and 30 advanced stage cases) and 66 normal control subjects. Macular GCIPLT was measured using Cirrus spectral domain-optical coherence tomography. Standard ...

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    2. Comparison of spectral-domain optical coherence tomography for intra-retinal layers thickness ...

      Comparison of spectral-domain optical coherence tomography for intra-retinal layers thickness ...

      Purpose To compare intra-retinal layer thickness measurements between eyes with no or mild diabetic retinopathy (DR) and age-matched controls using Spectralis spectral-domain optical coherence tomography (SD-OCT). Methods Cross-sectional observational analysis study. High-resolution macular volume scans (30° * 25°) were obtained for 133 type 2 diabetes mellitus (T2DM) patients with no DR, 42 T2DM patients with mild DR and 115 healthy controls. The mean thickness was measured in all 9 Early Treatment Diabetic Retinopathy Study (ETDRS) sectors for 8 separate layers, inner retinal layer (IRL), outer retinal layer (ORL) and total retina (TR), after automated segmentation. The ETDRS grid consisted of three ...

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    3. OCT-angiography: A qualitative and quantitative comparison of 4 OCT-A devices

      OCT-angiography: A qualitative and quantitative comparison of 4 OCT-A devices

      Article Authors Metrics Comments Related Content Abstract Introduction Methods Results Discussion Supporting information Acknowledgments Author Contributions References Reader Comments (0) Media Coverage Figures Abstract Purpose To compare the quality of four OCT-angiography(OCT-A) modules. Method The retina of nineteen healthy volunteers were scanned with four OCT-devices (Topcon DRI-OCT Triton Swept-source OCT, Optovue RTVue-XR, a prototype Spectralis OCT2, Heidelberg-Engineering and Zeiss Cirrus 5000-HD-OCT). The device-software generated en-face OCT-A images of the superficial (SCP) and deep capillary plexuses (DCP) were evaluated and scored by 3 independent retinal imaging experts. The SCP vessel density was assessed using Angiotool-software. After the inter-grader reliability assessment ...

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    4. Influence of eye biometrics and corneal micro-structure on noncontact tonometry

      Influence of eye biometrics and corneal micro-structure on noncontact tonometry

      Purpose Tonometry is widely used as the main screening tool supporting glaucoma diagnosis. Still, its accuracy could be improved if full knowledge about the variation of the corneal biomechanical properties was available. In this study, Optical Coherence Tomography (OCT) speckle statistics are used to infer the organisation of the corneal micro-structure and hence, to analyse its influence on intraocular pressure (IOP) measurements. Methods Fifty-six subjects were recruited for this prospective study. Macro and micro-structural corneal parameters as well as subject age were considered. Macro-structural analysis included the parameters that are associated with the ocular anatomy, such as central corneal thickness ...

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    5. Quantitative microvascular analysis of retinal venous occlusions by spectral domain optical coherence tomography angiography

      Quantitative microvascular analysis of retinal venous occlusions by spectral domain optical coherence tomography angiography

      Purpose To quantitatively evaluate the retinal microvasculature in human subjects with retinal venous occlusions (RVO) using optical coherence tomography angiography (OCTA). Design Retrospective, cross-sectional, observational case series. Participants Sixty subjects (84 eyes) were included (20 BRVO, 14 CRVO, 24 unaffected fellow eyes, and 26 controls). Methods OCTA was performed on a prototype, spectral domain-OCTA system in the 3x3mm central macular region. Custom software was used to quantify morphology and density of retinal capillaries using four quantitative parameters. The vasculature of the segmented retinal layers and nonsegmented whole retina were analyzed. Main outcome measures Fractal dimension (FD), vessel density (VD), skeletal ...

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    6. Measurements of the parapapillary atrophy zones in en face optical coherence tomography images

      Measurements of the parapapillary atrophy zones in en face optical coherence tomography images

      Objective To measure the parapapillary atrophy (PPA) area in en face images obtained with swept-source optical coherence tomography (SS-OCT), and to evaluate its relationship to glaucoma, myopia, and age in non-highly myopic subjects. Design Retrospective, cross-sectional study. Participants Fifty eyes of 30 subjects with open-angle glaucoma (G group) and forty-three eyes of 26 healthy control subjects (C group). Eyes with high myopia (spherical equivalent refractive error ≤ -8 diopters or axial length ≥ 26.5 mm) were excluded. Methods Mean age ± standard deviation was 59.9 ± 12.4 years. The beta zone and the gamma zone PPA areas were measured in en ...

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    7. Validation of full-field optical coherence tomography in distinguishing malignant and benign tissue in resected pancreatic cancer specimens

      Validation of full-field optical coherence tomography in distinguishing malignant and benign tissue in resected pancreatic cancer specimens

      Background Pancreatic cancer is the fourth leading cause of cancer-related mortality in the United States. The minority of patients can undergo curative-intended surgical therapy due to progressive disease stage at time of diagnosis. Nonetheless, tumor involvement of surgical margins is seen in up to 70% of resections, being a strong negative prognostic factor. Real-time intraoperative imaging modalities may aid surgeons to obtain tumor-free resection margins. Full-field optical coherence tomography (FF-OCT) is a promising diagnostic tool using high-resolution white-light interference microscopy without tissue processing. Therefore, we composed an atlas of FF-OCT images of malignant and benign pancreatic tissue, and investigated the ...

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    8. Polarization image segmentation of radiofrequency ablated porcine myocardial tissue

      Polarization image segmentation of radiofrequency ablated porcine myocardial tissue

      Optical polarimetry has previously imaged the spatial extent of a typical radiofrequency ablated (RFA) lesion in myocardial tissue, exhibiting significantly lower total depolarization at the necrotic core compared to healthy tissue, and intermediate values at the RFA rim region. Here, total depolarization in ablated myocardium was used to segment the total depolarization image into three (core, rim and healthy) zones. A local fuzzy thresholding algorithm was used for this multi-region segmentation, and then compared with a ground truth segmentation obtained from manual demarcation of RFA core and rim regions on the histopathology image. Quantitative comparison of the algorithm segmentation results ...

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    9. Assessment of the retinal posterior pole in dominant optic atrophy by spectral-domain optical coherence tomography and microperimetry

      Assessment of the retinal posterior pole in dominant optic atrophy by spectral-domain optical coherence tomography and microperimetry

      Background To assess posterior pole (PP) retinal structure in patients with genetically confirmed autosomal dominant optic atrophy (ADOA) using new spectral domain optical coherence tomography (SD-OCT) segmentation technology. To analyze retinal PP thickness in relation to retinal sensitivity data from microperimetry (MP) in ADOA patients. Methods and findings This prospective cross-sectional study included 11 patients with ADOA and 11 age-matched healthy subjects. All participants underwent both a “Posterior Pole” and “peripapillary RNFL (pRNFL)” scanning protocol using SD-OCT. Functional mapping of the PP was also performed using MP. A customized program was implemented in order to achieve accurate superimposition of MP ...

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      Mentions: Nidek
    10. A comparison of the diagnostic ability of vessel density and structural measurements of optical coherence tomography in primary open angle glaucoma

      A comparison of the diagnostic ability of vessel density and structural measurements of optical coherence tomography in primary open angle glaucoma

      Purpose To compare the diagnostic abilities of vessel density measurements of the optic nerve head (ONH), peripapillary and macular regions on optical coherence tomography (OCT) angiography in eyes with primary open angle glaucoma (POAG) with that of the ONH rim area, peripapillary retinal nerve fiber layer (RNFL) thickness and the macular ganglion cell complex (GCC) thickness measurements. Methods In a cross sectional study, 78 eyes of 50 control subjects and 117 eyes of 67 POAG patients underwent vessel density and structural measurements with spectral domain OCT. POAG was diagnosed based on the masked evaluation of optic disc stereo photographs. Area ...

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    11. In vivo images of the epidural space with two- and three-dimensional optical coherence tomography in a porcine model

      In vivo images of the epidural space with two- and three-dimensional optical coherence tomography in a porcine model

      Background No reports exist concerning in vivo optical coherence tomography visualization of the epidural space and the blood patch process in the epidural space. In this study, we produced real-time two-dimensional and reconstructed three-dimensional images of the epidural space by using optical coherence tomography in a porcine model. We also aimed to produce three-dimensional optical coherence tomography images of the dura puncture and blood patch process. Methods Two-dimensional and three-dimensional optical coherence tomography images were obtained using a swept source optical coherence tomography (SSOCT) system. Four laboratory pigs were intubated and ventilated after the induction of general anesthesia. An 18-gauge ...

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      Mentions: Wen-Chuan Kuo
    12. Optical coherence tomography angiography in eyes with good visual acuity recovery after treatment for optic neuritis

      Optical coherence tomography angiography in eyes with good visual acuity recovery after treatment for optic neuritis

      Objective To evaluate the retinal perfusion using optical coherence tomography (OCT) angiography in eyes with good visual acuity recovery after treatment for optic neuritis (ON). Methods Seven eyes of seven patients with good visual acuity recovery after treatment for monocular ON and seven eyes of each fellow eye used as controls were studied. Retinal perfusion around the disc and at the macula was evaluated using OCT angiography. The retinal nerve fiber layer thickness was measured around the disc. The ganglion cell layer complex thickness or the ganglion cell layer plus the inner plexiform layer thickness were measured at the macula ...

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    13. Optical coherence tomography segmentation analysis in relapsing remitting versus progressive multiple sclerosis

      Optical coherence tomography segmentation analysis in relapsing remitting versus progressive multiple sclerosis

      Introduction Optical coherence tomography (OCT) with retinal segmentation analysis is a valuable tool in assessing axonal loss and neuro-degeneration in multiple sclerosis (MS) by in-vivo imaging, delineation and quantification of retinal layers. There is evidence of deep retinal involvement in MS beyond the inner retinal layers. The ultra-structural retinal changes in MS in different MS phenotypes can reflect differences in the pathophysiologic mechanisms. There is limited data on the pattern of deeper retinal layer involvement in progressive MS (PMS) versus relapsing remitting MS (RRMS). We have compared the OCT segmentation analysis in patients with relapsing-remitting MS and progressive MS. Methods ...

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    14. Relationship between optical coherence tomography sector peripapillary angioflow-density and Octopus visual field cluster mean defect values

      Relationship between optical coherence tomography sector peripapillary angioflow-density and Octopus visual field cluster mean defect values

      Purpose To compare the relationship of Octopus perimeter cluster mean-defect (cluster MD) values with the spatially corresponding optical coherence tomography (OCT) sector peripapillary angioflow vessel-density (PAFD) and sector retinal nerve fiber layer thickness (RNFLT) values. Methods High quality PAFD and RNFLT images acquired on the same day with the Angiovue/RTVue-XR Avanti OCT (Optovue Inc., Fremont, USA) on 1 eye of 27 stable early-to-moderate glaucoma, 22 medically controlled ocular hypertensive and 13 healthy participants were analyzed. Octopus G2 normal visual field test was made within 3 months from the imaging. Results Total peripapillary PAFD and RNFLT showed similar strong positive ...

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    15. Optical measurements of paintings and the creation of an artwork database for authenticity

      Optical measurements of paintings and the creation of an artwork database for authenticity

      Paintings have high cultural and commercial value, so that needs to be preserved. Many techniques have been attempted to analyze properties of paintings, including X-ray analysis and optical coherence tomography (OCT) methods, and enable conservation of paintings from forgeries. In this paper, we suggest a simple and accurate optical analysis system to protect them from counterfeit which is comprised of fiber optics reflectance spectroscopy (FORS) and line laser-based topographic analysis. The system is designed to fully cover the whole area of paintings regardless of its size for the accurate analysis. For additional assessments, a line laser-based high resolved OCT was ...

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    16. Retinal vessel density from optical coherence tomography angiography to differentiate early glaucoma, pre-perimetric glaucoma and normal eyes

      Retinal vessel density from optical coherence tomography angiography to differentiate early glaucoma, pre-perimetric glaucoma and normal eyes

      Purpose To evaluate optic nerve vascular density using swept source optical coherence tomography angiography (OCTA) in patients with early primary open angle glaucoma (POAG), pre-perimetric glaucoma and normal eyes. Methods This is a prospective, observational study including 56 eyes in total and divided into 3 groups; 20 eyes with mild POAG, 20 pre-perimetric glaucoma eyes, and 16 age-matched normal eyes as controls. The optic disc region was imaged by a 1050-nm-wavelength swept-source OCT system (DRI OCT Triton, TOPCON). Vessel density was assessed as the ratio of the area occupied by the vessels in 3 distinct regions: 1) within the optic ...

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    17. Optical Coherence Tomography Angiography Findings in Stargardt Disease

      Optical Coherence Tomography Angiography Findings in Stargardt Disease

      Background to assess vessel density of superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) in advanced Stargardt disease (STGD) using optical coherence tomography angiography (OCTA) and correlate these findings with macular function using pattern electroretinogram (PERG) and multifocal electroretinogram (mfERG). Methods Twelve patients (24 eyes) with advanced STGD underwent vessel densities and macular thickness measurements using OCTA. A control group of 24 healthy controls (24 eyes) was chosen for comparison. In the STGD group correlation between vessel density and macular thickness and between macular function and morphologic parameters were evaluated. Results Whole parafoveal vessel density (VD) of ...

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      Mentions: Optovue
    18. 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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    19. Multi-Channel Optical Coherence Elastography Using Relative and Absolute Shear-Wave Time of Flight

      Multi-Channel Optical Coherence Elastography Using Relative and Absolute Shear-Wave Time of Flight

      Elastography, the imaging of elastic properties of soft tissues, is well developed for macroscopic clinical imaging of soft tissues and can provide useful information about various pathological processes which is complementary to that provided by the original modality. Scaling down of this technique should ply the field of cellular biology with valuable information with regard to elastic properties of cells and their environment. This paper evaluates the potential to develop such a tool by modifying a commercial optical coherence tomography (OCT) device to measure the speed of shear waves propagating in a three-dimensional (3D) medium. A needle, embedded in the ...

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    20. Visualization of Radial Peripapillary Capillaries Using Optical Coherence Tomography Angiography: The Effect of Image Averaging

      Visualization of Radial Peripapillary Capillaries Using Optical Coherence Tomography Angiography: The Effect of Image Averaging

      Objectives To assess the effect of image registration and averaging on the visualization and quantification of the radial peripapillary capillary (RPC) network on optical coherence tomography angiography (OCTA). Methods Twenty-two healthy controls were imaged with a commercial OCTA system (AngioVue, Optovue, Inc.). Ten 10x10° scans of the optic disc were obtained, and the most superficial layer (50-μm slab extending from the inner limiting membrane) was extracted for analysis. Rigid registration was achieved using ImageJ, and averaging of each 2 to 10 frames was performed in five ~2x2° regions of interest (ROI) located 1° from the optic disc margin. The ...

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    21. Optical Coherence Tomographic Features and Prognosis of Pneumatic Displacement for Submacular Hemorrhage

      Optical Coherence Tomographic Features and Prognosis of Pneumatic Displacement for Submacular Hemorrhage

      Purpose To identify prognostic factors, including optical coherence tomographic features, of visual outcome in exudative age-related macular degeneration with submacular hemorrhage treated with pneumatic displacement. Methods This retrospective interventional case series included 37 eyes with exudative age-related macular degeneration and submacular hemorrhage, all of which underwent pneumatic displacement. The best-corrected visual acuity (BCVA) was measured at diagnosis and at 3 and 6 months after treatment. In addition to demographic and funduscopic parameters, tomographic features such as reflectance of the submacular hemorrhage were analyzed with regard to BCVA at 6 months. Results After pneumatic displacement and a subsequent treatment such as ...

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    22. Enhanced Visualization of Subtle Outer Retinal Pathology by En Face Optical Coherence Tomography and Correlation with Multi-Modal Imaging

      Enhanced Visualization of Subtle Outer Retinal Pathology by En Face Optical Coherence Tomography and Correlation with Multi-Modal Imaging

      Purpose To present en face optical coherence tomography (OCT) images generated by graph-search theory algorithm-based custom software and examine correlation with other imaging modalities. Methods En face OCT images derived from high density OCT volumetric scans of 3 healthy subjects and 4 patients using a custom algorithm (graph-search theory) and commercial software (Heidelberg Eye Explorer software (Heidelberg Engineering)) were compared and correlated with near infrared reflectance, fundus autofluorescence, adaptive optics flood-illumination ophthalmoscopy (AO-FIO) and microperimetry. Results Commercial software was unable to generate accurate en face OCT images in eyes with retinal pigment epithelium (RPE) pathology due to segmentation error at ...

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    23. Collagen Fiber Orientation and Dispersion in the Upper Cervix of Non-Pregnant and Pregnant Wome

      Collagen Fiber Orientation and Dispersion in the Upper Cervix of Non-Pregnant and Pregnant Wome

      The structural integrity of the cervix in pregnancy is necessary for carrying a pregnancy until term, and the organization of human cervical tissue collagen likely plays an important role in the tissue’s structural function. Collagen fibers in the cervical extracellular matrix exhibit preferential directionality, and this collagen network ultrastructure is hypothesized to reorient and remodel during cervical softening and dilation at time of parturition. Within the cervix, the upper half is substantially loaded during pregnancy and is where the premature funneling starts to happen. To characterize the cervical collagen ultrastructure for the upper half of the human cervix, we ...

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    24. Aortic and Cardiac Structure and Function Using High-Resolution Echocardiography and Optical Coherence Tomography in a Mouse Model of Marfan Syndrome

      Aortic and Cardiac Structure and Function Using High-Resolution Echocardiography and Optical Coherence Tomography in a Mouse Model of Marfan Syndrome

      Marfan syndrome (MFS) is an autosomal-dominant disorder of connective tissue caused by mutations in the fibrillin-1 (FBN1) gene. Mortality is often due to aortic dissection and rupture. We investigated the structural and functional properties of the heart and aorta in a [ Fbn1 C1039G/+ ] MFS mouse using high-resolution ultrasound (echo) and optical coherence tomography (OCT). Echo was performed on 6- and 12-month old wild type (WT) and MFS mice (n = 8). In vivo pulse wave velocity (PWV), aortic root diameter, ejection fraction, stroke volume, left ventricular (LV) wall thickness, LV mass and mitral valve early and atrial velocities (E/A) ratio ...

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