1. Articles from Yanling Ouyang

    1-25 of 25
    1. Retinal vessel diameter changes in different severities of diabetic retinopathy by SD-OCT

      Retinal vessel diameter changes in different severities of diabetic retinopathy by SD-OCT

      To evaluate retinal vessel diameters in relation to different severity grades of diabetic retinopathy (DR) using spectral-domain optical coherence tomography (SD-OCT). Patients with varying degrees of nonproliferative DR (NPDR) underwent circular OCT scans centered on the optic nerve head using a SD-OCT. These cases were retrospectively reviewed. The presence and severity of DR was assessed using Early Treatment Diabetic Retinopathy Study protocols. The 5 largest retinal arterioles and venules were labeled and measured on OCT scans for each patient according to previously published methods. Vertical vessel inner contour diameter, vertical vessel outer contour diameter, and reflectance shadowing width were among ...

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    2. Subretinal fluid in eyes with active ocular toxoplasmosis observed using spectral domain optical coherence tomography

      Subretinal fluid in eyes with active ocular toxoplasmosis observed using spectral domain optical coherence tomography

      Purpose To describe the clinical finding of subretinal fluid (SRF) in the posterior pole by spectral domain optical coherence tomography (SD-OCT) in eyes with active ocular toxoplasmosis (OT). Design Retrospective case series. Participants Thirty-eight eyes from 39 patients with active OT. Methods Eyes with active OT which underwent SD-OCT were reviewed. SRFs in the posterior pole were further analyzed. Main Outcome Measures Presence of SRF; its accompanying features, e.g. retinal necrosis, cystoid macular edema (CME), choroidal neovascularization (CNV); and longitudinal changes of SRF, including maximum height and total volume before and after treatment. Results SRF presented in 45.5 ...

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    3. Retinal vessel diameter measurements by spectral domain optical coherence tomography

      Retinal vessel diameter measurements by spectral domain optical coherence tomography

      Purpose To describe a spectral domain optical coherence (OCT)-assisted method of measuring retinal vessel diameters. Methods All Patients with an OCT circle scan centered at the optic nerve head using a Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) were retrospectively reviewed. Individual retinal vessels were identified on infrared reflectance (IR) images and given unique labels both on IR and spectral domain OCT (SD-OCT). Vessel width and vessel types obtained by IR were documented as ground truth. From OCT, measurements of each vessel, including horizontal vessel contour diameter, vertical vessel contour diameter, horizontal hyperreflective core diameter, and reflectance shadowing width, were ...

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    4. An easy method to differentiate retinal arteries from veins by spectral domain optical coherence tomography: retrospective, observational case series

      An easy method to differentiate retinal arteries from veins by spectral domain optical coherence tomography: retrospective, observational case series

      Background Recently it was shown that retinal vessel diameters could be measured using spectral domain optical coherence tomography (OCT). It has also been suggested that retinal vessels manifest different features on spectral domain OCT (SD-OCT) depending on whether they are arteries or veins. Our study was aimed to present a reliable SD-OCT assisted method of differentiating retinal arteries from veins. Methods Patients who underwent circular OCT scans centred at the optic disc using a Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany) were retrospectively reviewed. Individual retinal vessels were identified on infrared reflectance (IR) images and given unique labels for subsequent grading ...

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    5. Evaluation of cystoid change phenotypes in ocular toxoplasmosis using optical coherence tomography

      Evaluation of cystoid change phenotypes in ocular toxoplasmosis using optical coherence tomography

      Purpose To present unique cystoid changes occurring in patients with ocular toxoplasmosis observed in spectral domain optical coherence tomography (OCT). Methods Forty-six patients (80 eyes) with a diagnosis of ocular toxoplasmosis, who underwent volume OCT examination between January 2005 and October 2012, were retrospectively collected. Review of clinical examination findings, fundus photographs, fluorescein angiograms (FA) and OCT image sets obtained at initial visits and follow-up. Qualitative and quantitative analyses of cystoid space phenotypes visualized using OCT. Results Of the 80 eyes included, 17 eyes (15 patients) demonstrated cystoid changes in the macula on OCT. Six eyes (7.5%) had cystoid ...

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    6. The Retinal Disease Screening Study: Retrospective Comparison of Nonmydriatic Fundus Photography and Three-Dimensional Optical Coherence Tomography for Detection of Retinal Irregularities

      The Retinal Disease Screening Study: Retrospective Comparison of Nonmydriatic Fundus Photography and Three-Dimensional Optical Coherence Tomography for Detection of Retinal Irregularities

      Purpose. To determine the sensitivity of three-dimensional optical coherence tomography (3D-OCT) versus single field nonmydriatic fundus photography (FP) for detection of a variety of retinal abnormalities. Methods. Images from consecutive patients in a retina clinic undergoing simultaneous 3D-OCT (512×128) and single, foveal nonmydriatic 45° color fundus imaging with 3D-OCT-1000 in a 4 month-period were retrospectively collected. Findings from each modality were graded independently by two graders as present, questionable, or absent. Irregularities were separated into three categories for intermodality comparisons: epiretinal, retinal/subretinal, and RPE/choroidal irregularities. The approximate location of findings in relation to the 3D-OCT field was ...

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    7. Comparison of Non-Mydriatic Fundus Photography and Three Dimensional Optical Coherence Tomography for Detection of Retinal Irregularities

      Comparison of Non-Mydriatic Fundus Photography and Three Dimensional Optical Coherence Tomography for Detection of Retinal Irregularities

      Purpose:To determine the sensitivity of detection for retinal abnormalities using 3D-OCT versus single field fundus imaging. Methods:Images from consecutive patients in a retina clinic undergoing simultaneous 3D-OCT (512x128) and single, foveal non-mydriatic 45 degree color fundus imaging with 3D-OCT-1000 (Topcon Corp, Tokyo, Japan) in a 4 months period were retrospectively collected. Findings for each modality were graded independently by two graders as present, questionable or absent. Findings were separated into 3 categories for intermodality comparisons: epiretinal, retinal/subretinal, and RPE/choroidal. The approximate location of findings in relation to the 3D-OCT field was noted as infield and out ...

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    8. Optical Coherence Tomography–Based Observation of the Natural History of Drusenoid Lesion in Eyes with Dry Age-Related Macular Degeneration

      Optical Coherence Tomography–Based Observation of the Natural History of Drusenoid Lesion in Eyes with Dry Age-Related Macular Degeneration

      Purpose To use spectral domain optical coherence tomography (SD-OCT) to investigate risk factors predictive for the development of atrophy of drusenoid lesions (DLs) (drusen and drusenoid pigment epithelium detachment) in eyes with non-neovascular age-related macular degeneration (NNVAMD). Design Cohort study. Participants Forty-one eyes from 29 patients with NNVAMD. Methods Patients with NNVAMD who underwent registered SD-OCT imaging over a minimum period of 6 months were reviewed. Drusenoid lesions that were accompanied by new atrophy onset at 6 months or last follow-up (FUL) were further analyzed. Detailed lesion change was described throughout the study period. Odds ratios (ORs) and risk for ...

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    9. Different phenotypes of the appearance of the outer plexiform layer on optical coherence tomography

      Different phenotypes of the appearance of the outer plexiform layer on optical coherence tomography

      Purpose To present a selected case series of different phenotypes of the normal outer plexiform layer (OPL) visualized by optical coherence tomography (OCT). Methods Five cases were selected to represent the spectrum of appearances of the OPL in this case series. Categorical descriptions of each manifestation were then developed. Additional SD-OCT scans were obtained from a normal volunteer to further support the hypothesis. Results The inner one-third of the OPL typically appears hyperreflective on OCT, while the outer two-thirds (Henle fiber layer) may have a more varied appearance. Six different phenotypes of Henle fiber layer reflectivity were noted in this ...

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    10. Evaluation of the Axial Location of Cystoid Spaces in Retinal Vein Occlusion Using Optical Coherence Tomography

      Evaluation of the Axial Location of Cystoid Spaces in Retinal Vein Occlusion Using Optical Coherence Tomography

      Purpose: To analyze the axial distribution of intraretinal cystoid changes in patients with retinal vein occlusion (RVO), incorporating a new hypothesis about the optical coherence tomographic boundary between the outer nuclear layer and the outer plexiform layer. Methods: Data were collected from patients with RVO who underwent spectral domain coherence tomography imaging. For each image set, certified graders evaluated each retinal layer for cystoid macular edema, defined as hyporeflective intraretinal cystoid spaces. Subretinal fluid, if present, was also noted. Results: Forty-eight eyes were evaluated (24 branch RVO, 18 central RVO, 6 hemiretinal vein occlusion). Cystoid macular edema was present in ...

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    11. The Retinal Disease Screening Study: Prospective Comparison of Nonmydriatic Fundus Photography and Optical Coherence Tomography for Detection of Retinal Irregularities

      The Retinal Disease Screening Study: Prospective Comparison of Nonmydriatic Fundus Photography and Optical Coherence Tomography for Detection of Retinal Irregularities

      Purpose. To compare the sensitivity of volume scanning with optical coherence tomography (OCT) to nonmydriatic color fundus photography (FP) for the detection of retinal irregularities in asymptomatic populations. Methods. Asymptomatic subjects without known ocular disease were recruited over a 6-month period. For each eye, two undilated 45° fundus images and four undilated volume OCT image sets covering the macula and optic nerve were obtained. Color images were evaluated for irregularities both inside and outside the area covered by OCT. OCT image sets were evaluated for internal limiting membrane irregularities, abnormal retinal thickness, hyper/hyporeflective features, and photoreceptor/retinal pigment epithelium ...

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    12. Semiautomated Segmentation of the Choroid in Spectral-domain Optical Coherence Tomography Volume Scans

      Semiautomated Segmentation of the Choroid in Spectral-domain Optical Coherence Tomography Volume Scans

      Purpose: Changes in the choroid, in particular its thickness, are believed to be of importance in the pathophysiology of a number of retinal diseases. The purpose of this study is to adapt the graph search algorithm to semi-automatically identify the choroidal layer in spectral-domain optical coherence tomography (SD-OCT) volume scans and compare its performance to manual delineation. Methods: A graph-based multi-stage segmentation approach was used to identify the choroid, defined as the layer between the outer border of the retinal pigment epithelium (RPE) band and the choroid-sclera junction. Thirty randomly chosen macular SD-OCT (Heidelberg Spectralis) volumes were obtained from 20 ...

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    13. The Retinal Disease Screening Study: Prospective Comparison of Non-Mydriatic FP and Optical Coherence Tomography for Detection of Retinal Irregularities

      The Retinal Disease Screening Study: Prospective Comparison of Non-Mydriatic FP and Optical Coherence Tomography for Detection of Retinal Irregularities

      Purpose:To compare the sensitivity of volume scanning with optical coherence tomography (OCT), to non-mydriatic fundus photography, for the detection of retinal abnormalities in asymptomatic populations. Methods:Asymptomatic subjects without known ocular disease recruited over a six-month period .For each eye, two undilated 45º fundus images, and four undilated volume OCT image sets covering the macula and optic nerve, were obtained. Fundus photographs were evaluated for abnormalities both inside and outside the fundal area covered by OCT. OCT image sets were evaluated for internal limiting membrane irregularities, abnormal retinal thickness, hyper/hyporeflective foci, and photoreceptor/retinal pigment epithelium irregularities. Detection ...

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    14. Juxtapapillary Pigment Epithelium Detachment Observed in Asymptomatic Participants using Optical Coherence Tomograph

      Juxtapapillary Pigment Epithelium Detachment Observed in Asymptomatic Participants using Optical Coherence Tomograph

      Purpose. To use three-dimensional optical coherence tomography (3D-OCT) to assess the prevalence of juxtapapillary retinal pigment epithelial detachments (jPED) in an asymptomatic population. Methods. Asymptomatic participants (i.e. family members of patients) were prospectively recruited over a six-month period. Each subject completed a questionnaire prior to the acquisition of two undilated 45º fundus images and two undilated raster 3D-OCT scans (512x128) covering the macula and optic nerve from each eye using 3D-OCT-1000 (Topcon Co, Tokyo). Fundus images were graded for the presence of peripapillary atrophy (PPA), peripapillary pigment (PPP), drusen in the macula and drusen elsewhere; while 3D-OCT scans were ...

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    15. Diurnal Variation of Choroidal Thickness in Normal, Healthy Subjects Measured by Spectral Domain Optical Coherence Tomography

      Diurnal Variation of Choroidal Thickness in Normal, Healthy Subjects Measured by Spectral Domain Optical Coherence Tomography
      Purpose. To describe the pattern and magnitude of diurnal variation of choroidal thickness (CT), its relation to systemic and ocular factors, and to determine the intervisit reproducibility of diurnal patterns. Methods. A prospective study was conducted on 12 healthy volunteers who each underwent sequential ocular imaging on two separate days at five fixed, 2-hour time intervals. Spectral domain optical coherence tomography (OCT) with enhanced depth imaging and image tracking was performed using a standardized protocol. Choroidal and retinal thicknesses were independently assessed by two masked graders. CT diurnal variation was assessed using repeated-measures ANOVA. Results. A significant diurnal variation in ...
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    16. Assessment of Differential Pharmacodynamic Effects using Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration

      Assessment of Differential Pharmacodynamic Effects using Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration

      Purpose: To assess the differential pharmacodynamic effects of bevacizumab (Avastin), pegaptanib (Macugen), and verteporfin photodynamic therapy (PDT), using novel OCT parameters, in a recently completed phase III/IV clinical trial. Methods: Data from 122 patients participating in the Avastin (Bevacizumab) for Choroidal neovascularization (ABC) trial, were evaluated. Stratus OCT images were analyzed using custom software - changes in volume of the neurosensory retina, subretinal fluid (SRF), pigment epithelium detachment (PED), and subretinal tissue, were calculated over the 54-week trial period. Results: Reductions in retinal oedema were more than twice as great from bevacizumab than pegaptanib (-0.82 mm3 versus -0.31 ...

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    17. Diurnal variation of choroidal thickness in normal, healthy subjects

      Diurnal variation of choroidal thickness in normal, healthy subjects
      Purpose: To describe the pattern and magnitude of diurnal variation of choroidal thickness (CT), its relation to systemic and ocular factors, and to determine the inter-visit reproducibility of diurnal patterns. Methods: A prospective study was conducted on 12 healthy volunteers who each underwent sequential ocular imaging on 2 separate days at 5 fixed, two-hourly time intervals. Spectral Domain Optical Coherence Tomography (OCT) with Enhanced Depth Imaging and image tracking was performed using a standardized protocol. Choroidal and retinal thicknesses were independently assessed by 2 masked graders. CT diurnal variation was assessed using repeated measures Analysis of Variance (ANOVA). Results: A ...
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    18. Clinical Significance of B-Scan Averaging With SD-OCT

      Clinical Significance of B-Scan Averaging With SD-OCT
      Averaging multiple scans is a potential advantage of optical coherence tomography. The authors evaluate the qualitative benefits of B-scan averaging on the visualization of outer retinal structures. A retrospective analysis was performed on Cirrus OCT (Carl Zeiss Meditec, Dublin, CA) B-scans from 1 eye of 35 patients referred to the imaging unit who underwent three types of scan acquisitions: no averaging, 4× averaging, and 20× averaging. Masked assessment of quality was made using a qualitative scale of 0 (worst) to 3 according to the ability to identify structure, brightness, and continuity. Quality scores consistently improved with 4× averaging, but improved ...
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    19. Simple Estimation of Clinically-Relevant Lesion Volumes using Spectral Domain-Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration

      Simple Estimation of Clinically-Relevant Lesion Volumes using Spectral Domain-Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration

      Purpose: To evaluate simple methods of estimating the volume of clinically-relevant features in neovascular age-related macular degeneration (NVAMD) using spectral domain OCT (SD-OCT). Methods: Using a database of NVAMD cases imaged with macular cube (512 x 128) SD-OCT scans from either a Cirrus HD-OCT (Carl Zeiss Meditec, Inc., Dublin, CA) or a 3D-OCT-1000 (Topcon, Inc., Tokyo, Japan), we retrospectively selected visits where CME, SRF or a PED were evident. Patients with single visits were analyzed in the cross-sectional analysis (CSA) and those with a baseline visit and 3 or more follow-up visits in the longitudinal analysis (LA). The volume of ...

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    20. Spatial Distribution of Posterior Pole Choroidal Thickness by Spectral Domain Optical Coherence Tomography

      Spatial Distribution of Posterior Pole Choroidal Thickness by Spectral Domain Optical Coherence Tomography
      Purpose: To study the spatial distribution of posterior pole choroidal thickness (CT) in healthy eyes using spectral domain optical coherence tomography (OCT). Methods: Fifty-nine eyes from 30 subjects with no retinal or choroidal disease were examined with the Cirrus HD-OCT (Carl Zeiss Meditec) using macular volume cube scanning protocols. A randomly chosen-subset also had multi-field analysis performed (volume scans centered on and surrounding the optic nerve head (ONH)). CT was manually quantified using a validated reading center tool (“3D-OCTOR”). For macular scans, mean CT was calculated for each Early Treatment Diabetic Retinopathy Study (ETDRS) subfield. Compound “posterior pole” CT maps ...
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    21. Comparison of manually corrected retinal thickness measurements from multiple spectral-domain optical coherence tomography instruments

      Comparison of manually corrected retinal thickness measurements from multiple spectral-domain optical coherence tomography instruments

      Background/aims To compare retinal thickness measurements from three different spectral domain optical coherence instruments when manual segmentation is employed to standardise retinal boundary locations. Methods 40 eyes of 21 healthy subjects were scanned on the Cirrus HD-OCT, Topcon 3D-OCT-2000 and Heidelberg Spectralis-OCT. Raw data were imported into custom grading software (3D-OCTOR). Manual segmentation was performed on every data set, and retinal thickness values in the foveal central subfield were computed. Results 37 eyes of 20 subjects were gradable on every machine. The average retinal thicknesses for these eyes were 236.7 µm (SD 20.1), 235.7 µm (SD ...

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    22. Acute Severe Visual Decrease After Photodynamic Therapy With Verteporfin: Spectral-Domain OCT Features

      Acute Severe Visual Decrease After Photodynamic Therapy With Verteporfin: Spectral-Domain OCT Features

      In this report, spectral-domain optical coherence tomography (OCT) was used to characterize the acute morphologic alterations that occur when photodynamic therapy with verteporfin results in an acute severe visual decrease. The clinical and imaging records of a patient with neovascular age-related macular degeneration who suffered this complication were reviewed. Using spectral-domain OCT, two relatively distinct subretinal fluid compartments were visualized: a sparsely hyperreflective pocket of subretinal fluid overlying the fibrovascular pigment epithelial detachment, consistent with fibrinous exudation, and a more homogenously hyporeflective compartment at the periphery of the choroidal neovascular lesion, consistent with serous exudation. The higher axial resolution, and ...

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    23. Relationship between Optical Coherence Tomography Retinal Parameters and Visual Acuity in Diabetic Macular Edema

      Relationship between Optical Coherence Tomography Retinal Parameters and Visual Acuity in Diabetic Macular Edema

      Purpose: To investigate the relationship between optical coherence tomography (OCT)-derived measurements of retinal morphology and visual acuity in patients with diabetic macular edema.Design: Retrospective cross-sectional study.Participants: A total of 67 consecutive patients (67 eyes) with diabetic macular edema (DME) who underwent Stratus OCT imaging (Carl Zeiss Meditec, Inc., Dublin, CA).Methods: Best-corrected Snellen visual acuity was recorded for each patient. Raw exported Stratus OCT images for each patient were analyzed using custom software entitled “OCTOR,” which allows the precise positioning of prespecified boundaries on individual B-scans. Thickness, volume, and intensity were calculated for neurosensory retina and subretinal ...

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    24. Detection of Cystoid Macular Edema with Three-Dimensional Optical Coherence Tomography versus Fluorescein Angiography

      Purpose: To compare the sensitivity and reproducibility of three-dimensional optical coherence tomography (3D-OCT) and fluorescein angiography (FA) for the detection of cystoid macular edema (CME). Methods: Data from all patients who underwent digital FA (Topcon 50IX, Topcon Corp.) and 512x128 horizontal raster 3D-OCT scans (3D-OCT-1000, Topcon Corp.) on the same day in a retina subspecialty clinic were retrospectively collected. Images were reviewed independently by four reading center graders and adjudicated as a group to render a single result for each eye and each imaging modality. Kappa statistics were used to determine the level of agreement between graders for each modality ...

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    25. Impact of Scanning Density on Measurements from Spectral Domain Optical Coherence Tomography

      Purpose: To investigate the relationship between B-scan density and retinal thickness measurements obtained by spectral domain optical coherence tomography (SDOCT) in eyes with retinal disease. Methods: Data were collected from 115 patients who underwent volume OCT imaging with Cirrus HD-OCT using the 512 x 128 horizontal raster protocol. Raw OCT data, including the location of the automated retinal boundaries, were exported from the Cirrus HD-OCT instrument and imported into the Doheny Image Reading Center (DIRC) OCT viewing and grading software, termed "3D-OCTOR". For each case, retinal thickness maps similar to those produced by Cirrus HD-OCT were generated using all 128 ...
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    1-25 of 25
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    1. (25 articles) Yanling Ouyang
    2. (22 articles) Srinivas R. Sadda
    3. (21 articles) University of Southern California
    4. (17 articles) Florian M. Heussen
    5. (15 articles) Alexander C. Walsh
    6. (15 articles) Pearse A. Keane
    7. (13 articles) University College London
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    Relationship between Optical Coherence Tomography Retinal Parameters and Visual Acuity in Diabetic Macular Edema Comparison of manually corrected retinal thickness measurements from multiple spectral-domain optical coherence tomography instruments Spatial Distribution of Posterior Pole Choroidal Thickness by Spectral Domain Optical Coherence Tomography Simple Estimation of Clinically-Relevant Lesion Volumes using Spectral Domain-Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration Clinical Significance of B-Scan Averaging With SD-OCT Assessment of Differential Pharmacodynamic Effects using Optical Coherence Tomography in Neovascular Age-Related Macular Degeneration Diurnal Variation of Choroidal Thickness in Normal, Healthy Subjects Measured by Spectral Domain Optical Coherence Tomography Optical Coherence Tomography–Based Observation of the Natural History of Drusenoid Lesion in Eyes with Dry Age-Related Macular Degeneration Indiana University Receives NIH Grant for Imaging Spatial and Temporal Dynamics of Retinal Ganglion Cells University of Houston Receives NIH Grant for Structural and Molecular Phenotyping of Embryonic Development Through Multi-Modal Optical Imaging. Massachusetts Institute of Technology Receives NIH Grant for Novel Optical Diagnostics with Optical Coherence Tomography Yale University Receives a NIH Grant for Xenopus As A Model System for Hydrocephaly and Ependymal Ciliogenesis