1. 1-24 of 355 1 2 3 4 ... 13 14 15 »
    1. Reply to Correspondence: Impact of Binarization Thresholding and Brightness/Contrast Adjustment Methodology on Optical Coherence Tomography Angiography Image Quantification

      Reply to Correspondence: Impact of Binarization Thresholding and Brightness/Contrast Adjustment Methodology on Optical Coherence Tomography Angiography Image Quantification

      We thank Dr Rabiolo and associates for their interest in our work and their correspondence.1 We also applaud them for their valuable study that examined the effect of binarization thresholding on vessel area density (VAD) in retinal vascular optical coherence tomography angiography (OCTA) images.2 In their correspondence, they highlight several points regarding our results and conclusions compared with their own findings.

      Read Full Article
    2. Correspondence: Impact of Binarization Thresholding and Brightness/Contrast Adjustment Methodology on Optical Coherence Tomography Angiography Image Quantification

      Correspondence: Impact of Binarization Thresholding and Brightness/Contrast Adjustment Methodology on Optical Coherence Tomography Angiography Image Quantification

      We read with interest the article by Mehta and colleagues titled “Impact of Binarization Thresholding and Brightness/Contrast Adjustment Methodology on Optical Coherence Tomography Angiography Image Quantification.” 1 The authors tested 5 methods to binarize optical coherence tomography angiography (OCT-A) en face angiocubes at the superficial capillary plexus (SCP) and choriocapillaris (CC) on a small cohort of healthy subjects. They found significant differences among the methods for the parameters studied, and the differences were more pronounced at the CC level.

      Read Full Article
    3. Influence of Bruch’s Membrane Opening Area in Diagnosing Glaucoma with Neuroretinal Parameters from Optical Coherence Tomography

      Influence of Bruch’s Membrane Opening Area in Diagnosing Glaucoma with Neuroretinal Parameters from Optical Coherence Tomography

      Purpose To determine whether the glaucoma diagnostic accuracy of age and Bruch’s membrane opening area (BMOA) adjusted normative classifications of minimum rim width (MRW) and retinal nerve fibre layer thickness (RNFLT) is dependent on BMOA, in a European descent population. Design Retrospective, cross-sectional study. Methods We included 182 glaucoma patients and 166 healthy controls for the primary study, and 105 glaucoma patients in a second sample used for a replication study. Optical coherence tomography (Spectralis) measurements of BMOA, global MRW and RNFLT and normative classifications from the device software were exported for analysis. Sensitivity and specificity were calculated for ...

      Read Full Article
    4. Quantification of choriocapillaris with OCTA: a comparison study

      Quantification of choriocapillaris with OCTA: a comparison study

      Purpose To demonstrate the variation in quantitative choriocapillaris (CC) metrics with various binarization approaches using optical coherence tomography angiography (OCTA). Design Retrospective, observational, cross-sectional case series. Methods 3x3 mm and 6x6 mm macular OCTA scans were obtained from normal eyes and from eyes with drusen secondary to AMD. The CC slab was extracted and the CC flow deficits (FDs) were segmented with two previously published algorithms: fuzzy C-means approach (FCM method) and Phansalkar’s local thresholding (Phansalkar method). Four different values for the radius were used in order to investigate the effect on the FD segmentation when using the Phansalkar ...

      Read Full Article
    5. Optical Coherence Tomography normative peripapillary retinal nerve fiber layer and macular data in children ages 0-5 years

      Optical Coherence Tomography normative peripapillary retinal nerve fiber layer and macular data in children ages 0-5 years

      Purpose To determine reference values for the peripapillary retinal nerve fiber layer (pRNFL) and macula in children ages 0-5 years. Design Prospective cross-sectional study Setting Single large academic pediatric ophthalmology practice Study Population Healthy, full-term children ages 0 to <6 years presenting for surgery under general anesthesia were prospectively recruited for participation. Excluded were children with systemic neurologic disease, optic nerve or retinal disease (even if unilateral), or any bilateral ocular disease process, and eyes with amblyopia, ocular disease, or spherical equivalent refractive error outside of -3.00 to +8.00 diopters. Observation Procedure Following general anesthesia, OCT scans of ...

      Read Full Article
    6. Prediction of Glaucoma Progression with Structural Parameters: Comparison of Optical Coherence Tomography and Clinical Disc Parameters

      Prediction of Glaucoma Progression with Structural Parameters: Comparison of Optical Coherence Tomography and Clinical Disc Parameters

      Purpose To test the hypothesis that baseline optical coherence tomography (OCT) measures predict visual field (VF) progression in a cohort of patients with suspected or established glaucoma and compare their performance to semiquantitative optic disc measures. Design Observational cohort study. Methods Setting: Academic institution. Study Population One-hundred seventy-one eyes of 95 patients with good-quality baseline retinal nerve fiber layer (RNFL) and macular OCT images and disc photographs with >2 years of follow-up and ≥5 VFs. Observation Procedures Baseline macular and RNFL OCT measures and cup-to-disc ratio and disc damage likelihood score. Main Outcome Measures Prediction of glaucomatous visual field deterioration ...

      Read Full Article
    7. Two-Year Risk of Exudation in Eyes with Non-Exudative AMD and Subclinical Neovascularization Detected with Swept Source OCT Angiography

      Two-Year Risk of Exudation in Eyes with Non-Exudative AMD and Subclinical Neovascularization Detected with Swept Source OCT Angiography

      Purpose Swept source optical coherence tomography angiography (SS-OCTA) was used to study the prevalence, incidence, and natural history of subclinical macular neovascularization (MNV) in eyes with unilateral non-exudative age-related macular degeneration (AMD). Design Prospective cohort study. Methods Patients were imaged using 3x3 mm and 6x6 mm SS-OCTA scan patterns. MNV was detected using the outer retina to choriocapillaris en face slab. Prevalence and incidence of subclinical MNV, Kaplan-Meier cumulative estimates for the overall risk of exudation, and the association between neovascular lesion size and the risk of exudation were assessed through 2 years. Results From August 2014 through March 2018 ...

      Read Full Article
    8. Handheld Optical Coherence Tomography Normative Inner Retinal Layer Measurements for Children

      Handheld Optical Coherence Tomography Normative Inner Retinal Layer Measurements for Children

      Purpose Measurements of the ganglion cell complex (GCC), comprising the retinal nerve fiber (RNFL), ganglion cell, and inner plexiform layers, can be correlated with vision loss caused by optic nerve disease. Handheld optical coherence tomography (HH-OCT) can be used with sedation in children not amenable to traditional imaging. Purpose: to report GCC and RNFL measurements in normal children using HH-OCT. Design Prospective observational study of normal children ≤ 5-years of age. Methods Healthy, full-term children ≤5 years-old undergoing sedation or anesthesia were enrolled. Exclusion criteria: prematurity, pre-existing neurologic, genetic, metabolic or intraocular pathology. Demographic data, axial length (Master-Vu Sonomed Escalon, NY ...

      Read Full Article
    9. Retinal And Choroidal Optical Coherence Tomography Findings Of Carotid Cavernous Fistula

      Retinal And Choroidal Optical Coherence Tomography Findings Of Carotid Cavernous Fistula

      PURPOSE To define the retinal and choroidal imaging findings of carotid cavernous fistula (CCF) including central foveal thickness (CFT), subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI) parameters and tortuosity indexes (TI) as compared to a control group (CG). DESIGN Cross-sectional study MATERIALS AND METHODS The spectral domain enhanced-depth imaging optical coherence tomography (SD-EDI-OCT) images of 19 eyes of 19 consecutive patients with angiographically proven CCF and 19 eyes of 19 age- and sex- matched healthy control subjects were included. The patient group was divided according to CCF venous drainage pattern as anterior (A-CCF: draining into ophthalmic veins) and posterior ...

      Read Full Article
    10. Differentiating veins from arteries on optical coherence tomography angiography by identifying deep capillary plexus vortices

      Differentiating veins from arteries on optical coherence tomography angiography by identifying deep capillary plexus vortices

      Purpose To introduce a simple method for differentiating retinal veins from arteries on optical coherence tomography angiography (OCTA). Design Cross-sectional pilot study. Methods Four default en face slabs including color depth encoded, greyscale full-thickness retina, superficial plexus, and deep capillary plexus (DCP) from 9 3x3 mm and 9 6x6 mm OCTA scans were exported and aligned. Nine ophthalmologists with minimum OCTA experience from 2 eye institutions were instructed to classify labeled vessels as arteries or veins in 3 stages. Classification was performed based on graders’ own assessment at Stage 1. Graders were taught that a capillary-free zone was an anatomic ...

      Read Full Article
      Mentions: K. Bailey Freund
    11. Use of High-Resolution Optical Coherence Tomography in the Surgical Management of Ocular Surface Squamous Neoplasia: A Pilot Study

      Use of High-Resolution Optical Coherence Tomography in the Surgical Management of Ocular Surface Squamous Neoplasia: A Pilot Study

      Purpose To evaluate whether high-resolution optical coherence tomography (HR-OCT) can detect histologic tumor margins of ocular surface squamous neoplasia (OSSN). Methods Eight eyes of 8 patients with OSSN undergoing excision were studied prospectively. Immediately before surgery, the tumor was imaged using a commercially available HR-OCT (Bioptigen/Leica Microsystems, Buffalo Grove, IL) to identify the conjunctival margins of the neoplastic lesion. The tumor borders of the lesion determined by HR-OCT were mapped in relation to an anatomical reference point and transferred intraoperatively. The tumor was excised with 4 mm margins from the visible edge of the lesion with a “no-touch” technique ...

      Read Full Article
    12. Correlation of Outer Retinal Degeneration and Choriocapillaris Loss in Stargardt Disease Using En Face Optical Coherence Tomography and Optical Coherence Tomography Angiography

      Correlation of Outer Retinal Degeneration and Choriocapillaris Loss in Stargardt Disease Using En Face Optical Coherence Tomography and Optical Coherence Tomography Angiography

      Purpose This study measured and correlated degeneration of the junction between the inner and outer segments (IS/OS), the retinal pigment epithelium (RPE), and the choriocapillaris (CC) in Stargardt disease (STGD). Design Prospective cross-sectional study. Methods This study was conducted at the Casey Eye Institute. A total of 23 patients with STGD were enrolled and underwent optical coherence tomography angiography (OCTA). Scans were centered on the fovea. OCT slab projections and en face boundary maps were used to create masks to measure total IS/OS loss or RPE atrophy as well as regions of isolated IS/OS loss, isolated RPE ...

      Read Full Article
    13. Anterior Segment Optical Coherence Tomography Angiography Imaging of Conjunctiva and Intrasclera in Treated Primary Open-Angle Glaucoma

      Anterior Segment Optical Coherence Tomography Angiography Imaging of Conjunctiva and Intrasclera in Treated Primary Open-Angle Glaucoma

      Purpose To investigate conjunctival and intrascleral vasculature in glaucoma eyes using anterior segment (AS)-optical coherence tomography angiography (OCTA) and assess the factors contributing to the vessel density in AS-OCTA images. Design Prospective, cross-sectional study. Methods Thirty-four patients with primary open-angle glaucoma and 20 healthy subjects were included. A swept-source OCT system was used to obtain AS-OCTA images of the corneal limbus at the nasal and temporal quadrants. Vessel densities were measured in the superficial (from the conjunctival epithelium to a depth of 200 μm) and deep (from a depth of 200 μm to 1000 μm) layers. The vessel density ...

      Read Full Article
    14. Longitudinal Macular Structure-Function Relationships in Glaucoma and Their Sources of Variability

      Longitudinal Macular Structure-Function Relationships in Glaucoma and Their Sources of Variability

      Purpose 1) Review central structure-function (SF) relationships in glaucoma; 2) compare contributions of within-session and between-session variability to total variability of macular optical coherence tomography (OCT) thickness measurements; and 3) test the hypothesis that longitudinal within-eye variability of central SF relationships is smaller than between-individual variability. Methods We reviewed the pertinent literature on central SF relationships in glaucoma. Thirty-eight eyes (20 normal or glaucoma subjects) had ×3 macular images per session over 3 sessions and superpixels thickness measurements for ganglion cell layer (GCL), ganglion cell/inner plexiform layer (GCIPL), ganglion cell complex (GCC) and full macular thickness (FMT) were exported ...

      Read Full Article
    15. Improved Macular Capillary Flow On Optical Coherence Tomography Angiography After Panretinal Photocoagulation For Proliferative Diabetic Retinopathy

      Improved Macular Capillary Flow On Optical Coherence Tomography Angiography After Panretinal Photocoagulation For Proliferative Diabetic Retinopathy

      Purpose To evaluate the macular microvascular changes in eyes with proliferative diabetic retinopathy (PDR) following panretinal photocoagulation (PRP) Methods Using OCT angiography, we prospectively studied 10 eyes of 10 subjects with high risk PDR immediately before, 1 month and 3-6 months following PRP, using 3x3mm OCTA scan at each visit. The following parameters were calculated for the superficial (SCP), middle (MCP), and deep capillary plexuses (DCP): parafoveal vessel density, adjusted flow index (AFI) and percent area of non-perfusion (PAN). Parafoveal SCP vessel length density (VLD) was also evaluated. We performed univariate and multivariable statistics, adjusting for age and signal strength ...

      Read Full Article
    16. Anterior segment optical coherence tomographic angiography assessment of acute chemical injury

      Anterior segment optical coherence tomographic angiography assessment of acute chemical injury

      Purpose To compare routine clinical examination with optical coherence tomography angiography (OCTA) for the assessment of limbal conjunctival ischemia following a chemical burn. Setting Validity analysis Methods We assessed ten participants (15 eyes) with an acute chemical injury. Clinical photographs were used to determine the extent of any limbal conjunctival epithelial defect and ischemia. These were compared with the extent of limbal ischemia identified on OCTA images of the ocular surface. Quantitative and longitudinal analysis using the OCTA software were also performed. Correlations with visual outcome were sought using clinical and OCTA-derived variables. Results The extent of clinically determined limbal ...

      Read Full Article
    17. Development of a spatial model of age-related change in the macular ganglion cell layer to predict function from structural changes

      Development of a spatial model of age-related change in the macular ganglion cell layer to predict function from structural changes

      Purpose To develop location specific models of normal, age-related changes in the macular ganglion cell layer (GCL) from optical coherence tomography (OCT). Using these OCT-derived models, we predicted visual field (VF) sensitivity and compared these results to actual VF sensitivities. Design Retrospective cohort study Methods Single eyes of 254 normal participants were retrospectively enrolled from the Centre for Eye Health (Sydney, Australia). Macular GCL measurements were obtained using Spectralis OCT. Cluster algorithms were performed to identify spatial patterns demonstrating similar age-related change. Quadratic and linear regression models were subsequently utilized to characterize age-related GCL decline. 40 participants underwent additional testing ...

      Read Full Article
    18. Optical Coherence Tomography Angiography for Evaluation of Reperfusion following Pterygium Surgery

      Optical Coherence Tomography Angiography for Evaluation of Reperfusion following Pterygium Surgery

      Purpose To describe the use of optical coherence tomography angiography (OCTA) to quantitatively monitor the conjunctival graft revascularization after pterygium excision and conjunctival autograft (CAG) transplantation. Design Prospective, interventional case series. Methods Ten patients undergoing pterygium excision and femtosecond laser-assisted CAG transplantation were included. OCTA was performed at 1 week, 1 and 3 months postoperatively at the CAG transplantation site and harvested area. The vessel density at three different depths: conjunctival epithelium or CAG epithelium, conjunctival stroma or CAG stroma, and episclera, was evaluated and quantified. The revascularization rate was assessed and correlated with the postoperative CAG thickness. Results No ...

      Read Full Article
    19. Impact of Binarization Thresholding and Brightness/Contrast Adjustment Methodology on Optical Coherence Tomography Angiography Image Quantification

      Impact of Binarization Thresholding and Brightness/Contrast Adjustment Methodology on Optical Coherence Tomography Angiography Image Quantification

      Purpose Binarization is a critical technique in OCTA image analysis, but there is no consistency in the method used in published OCTA studies. This study assessed whether differences in OCTA binarization and brightness/contrast adjustments affect quantification metrics. Design Prospective cross-sectional validity study Methods This was a single-center study examining 21 eyes of 11 healthy individuals. All eyes were imaged using the Carl Zeiss PLEX Elite 9000 swept source-OCTA, and quantitative metrics resulting from five binarization thresholding and five brightness/contrast adjustment methodologies were compared. All metrics were calculated for the superficial plexus and choriocapillaris (CC), as well as unaveraged ...

      Read Full Article
    20. Association of Macular and Circumpapillary Microvasculature with Visual Field Sensitivity in Advanced Glaucoma

      Association of Macular and Circumpapillary Microvasculature with Visual Field Sensitivity in Advanced Glaucoma

      Purpose To evaluate the association between optical coherence tomography angiography (OCTA) macular and circumpapillary vessel density and visual field mean deviation (MD) in advanced primary open angle glaucoma (POAG). Design Cross-sectional study. Methods Macula (superficial layer) and optic nerve head [ONH, with (capillary density :CD) and without (vessel density: VD) automated removal of large vessels] OCTA of 34 eyes (34 patients, MD < -10 dB) were investigated as macula whole image VD (wiVD), parafoveal VD (pfVD), ONH wiVD, wiCD, circumpapillary VD (cpVD), and cpCD. Spectral domain OCT circumpapillary retinal nerve fiber layer (cpRNFL), macular ganglion cell complex (GCC) and ganglion cell ...

      Read Full Article
    21. Optical Coherence Tomography Angiography Quantitative Assessment of Choriocapillaris Blood Flow in Central Serous Chorioretinopathy

      Optical Coherence Tomography Angiography Quantitative Assessment of Choriocapillaris Blood Flow in Central Serous Chorioretinopathy

      We would like to thank Sousa and associates for their insightful observations regarding our study. 1 We agree with their remark about the potential existence of other latent pachychoroid spectrum disorders among fellow eyes in patients with unilateral central serous chorioretinopathy (CSC). Thereby, the term “unaffected” was voluntarily chosen in our study, in contrast with the “healthy” eyes in the control group. As noted, a significant proportion of these unaffected fellow eyes could be categorized as uncomplicated pachychoroid (UCP) or pachychoroid pigment epitheliopathy (PPE), in opposition to strictly normal eyes.

      Read Full Article
    22. The LXXV Edward Jackson Memorial Lecture: Lessons Learned from Avastin and OCT: The Great, The Good, The Bad, and The Ugly

      The LXXV Edward Jackson Memorial Lecture: Lessons Learned from Avastin and OCT: The Great, The Good, The Bad, and The Ugly

      Purpose To describe the synergistic benefits and cost-savings from the use of optical coherence tomography (OCT) and vascular endothelial growth factor (VEGF) inhibitors, particularly intravitreal bevacizumab, in the treatment of exudative age-related macular degeneration (AMD) Design Retrospective literature review and personal perspective. Methods Retrospective literature review and personal perspective. Results The introduction of the first clinically useful OCT instrument coincided with early phase clinical trials of a drug that would become known as ranibizumab. OCT provided a non-invasive imaging strategy that unambiguously showed the macular fluid associated with exudative AMD and the ability of anti-VEGF therapy to resolve this fluid ...

      Read Full Article
    23. A Deep Learning System for Automated Angle-Closure Detection in Anterior Segment Optical Coherence Tomography Images

      A Deep Learning System for Automated Angle-Closure Detection in Anterior Segment Optical Coherence Tomography Images

      Purpose Anterior segment optical coherence tomography (AS-OCT) provides an objective imaging modality for visually identifying anterior segment structures. An automated detection system could assist ophthalmologists in interpreting AS-OCT images for presence of angle closure. Design Development of an artificial intelligence automated detection system for the presence of angle closure. Methods A deep learning system for automated angle-closure detection in AS-OCT images was developed, and this was compared with another automated angle-closure detection system based on quantitative features. A total of 4135 Visante AS-OCT images from 2113 subjects (8270 anterior chamber angle (ACA) images with 7375 open-angle and 895 angle-closure) were ...

      Read Full Article
    1-24 of 355 1 2 3 4 ... 13 14 15 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks