All Articles from Richard F. Spaide -Optical Coherence Tomography News

Articles from Richard F. Spaide

1-24 of 63 1 2 3 »
1. Lateral Resolution of a Commercial Optical Coherence Tomography Instrument
  
  Explore TVST Journal Jan 21 2022 Ophthalmology
  
  Purpose : The lateral resolution of an optical coherence tomography (OCT) instrument was considered to be equal to the illumination spot size on the retina. To evaluate the potential lateral resolution of the Spectralis OCT, an instrument calculated to have a 14 µm resolution. Methods : The lateral point spread function (PSF) was evaluated using diamond abrasive powder 0 to 1 µm in diameter in silicone elastomer and a validated target with 800 nm FeO particles in urethane. The amplitude transfer function was calculated from human OCT images. Finally, resolution was measured using the 1951 USAF target. Results : Measurement of the lateral ...
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  Mentions: Heidelberg Engineering
2. Denoising Swept Source Optical Coherence Tomography Volumetric Scans using a Deep Learning Model
  
  Explore LWW Online Nov 30 2021 Ophthalmology
  
  Purpose: To evaluate the use of a deep learning (DL) noise-reduction model on swept source optical coherence tomography (SS-OCT) volumetric scans. Methods: Three groups of images including single-line highly averaged foveal scans (Averaged images), foveal B-scans from volumetric scans using no averaging (Unaveraged images) and DL denoised versions of the latter (Denoised images) were obtained. We evaluated the potential increase in signal to noise ratio by evaluating the contrast to noise ratio (CNR) of the resultant images and measured the multi scale structural similarity index (MS-SSIM) to determine if the Unaveraged and Denoised images held true in structure to the ...
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  Mentions: Topcon Medical Systems
3. High Resolution Spectral Domain Optical Coherence Tomography of Multiple Evanescent White Dot Syndrome
  
  Explore LWW Online Sep 29 2021 Ophthalmology
  
  Purpose: To evaluate a patient with multiple evanescent white dot syndrome (MEWDS) with multimodal imaging including high resolution spectral domain optical coherence tomography (SD-OCT). Methods: The patient was evaluated with wide-field color and autofluorescence imaging, microperimetry, and near infrared imaging. SD-OCT was performed using an instrument capable of 3 µm axial resolution, the High-Resolution Heidelberg Spectralis. Results: 28 year-old woman developed photopsias and a scotoma in the field of vision of her left eye. She had multiple whitish spots with granularity in her fovea consistent with the diagnosis of MEWDS. She had supportive fluorescein angiographic and autofluorescence findings. Because of ...
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4. Correlation of choriocapillaris hemodynamic data from dynamic indocyanine green and optical coherence tomography angiography
  
  Explore Nature Publishing Group Aug 4 2021 Ophthalmology
  
  To investigate the correlation between posterior pole choroidal blood flow evaluated with digital subtraction indocyanine green angiography and enface optical coherence tomography angiography (OCTA). Imaging in animal study. The anatomy of 2 cynomogulus monkeys was studied. Each monkey was given a 0.75 mg/kg injection of indocyanine green in the saphenous vein. The dynamic angiographic filling sequence was recorded at 15 frames per second using the Heidelberg Spectralis. After image registration, sequential frame subtraction was used to image the dye front moving through the choroid. The OCTA was obtained by frame averaging nine separate choriocapillaris slab flow images obtained ...
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  Mentions: Singapore Eye Research Institute University of Sydney
5. Intermediate and Deep Capillary Plexuses in Machine Learning Segmentation of High-Resolution Optical Coherence Tomography Imaging
  
  Explore LWW Online Jan 25 2021 Ophthalmology
  
  Purpose: To describe imaging produced by machine learning based segmentation of high-resolution optical coherence tomography (OCT) imaging of the intermediate capillary plexus (ICP) and deep capillary plexus (DCP), layers of vessels not imaged well by dye-based angiography. Methods: Three healthy subjects with no ocular problems were imaged with spectral domain OCT using an instrument with a scanning speed of 85,000 A-scans per second and 3µm axial optical resolution. A random forest segmentation strategy was used to segment the ICP and DCP. The depth resolved imaging data was visualized with the help of volume rendering. Results: The high-resolution OCT ...
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  Mentions: Heidelberg Engineering
6. Negative Vessel Remodeling in Stargardt Disease Quantified with Volume-Rendered Optical Coherence Tomography Angiography
  
  Explore LWW Online Jan 14 2021
  
  Purpose: To quantify retinal vasculature changes in Stargardt disease1 with volume-rendered optical coherence tomography angiography (OCTA). Methods: OCTA volumes from heathy subjects and two subgroups of STGD1 patients with the presence/absence of definitely decreased autofluorescence (DDAF) areas were compared. OCTA vessel surface area (VSA) and vessel volume (VV) were measured in central zones (Z) of 1, 2 and 3mm diameter. Results: 29 eyes of 15 STGD1 patients (20/9 eyes with/without DDAF) and 30 eyes of 15 controls contributed data. An enlarged foveal avascular zone was found in STGD1 patients without and even more with DDAF associated with ...
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  Mentions: University of Freiburg University of Erlangen
7. Swept Source Optical Coherence Tomography Angiography Imaging of the Choriocapillaris
  
  Explore LWW Online Jan 9 2021 Ophthalmology
  
  Purpose: To analyze swept source optical coherence angiography (SS-OCTA) images acquired at different depths above and below the default location of the Zeiss PLEX Elite 9000. Methods: Normal eyes of subjects in their 20s and 30s were evaluated. Angiographic slab images were taken at the default location of 29-49 µm below the retinal pigment epithelium (RPE) as well as 21-41 µm through 52-72 µm below in steps. The images were processed using the projection removal function from the device´s software. Raw images were evaluated, as were images that underwent a published compensation technique that adjusts for light penetration to ...
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8. Deliberations of an International Panel of Experts on OCTA Nomenclature of nAMD
  
  Explore Ophthalmology Dec 30 2020 Ophthalmology
  
  A panel of imaging experts was assembled to review neovascular age-related macular degeneration optical coherence tomography angiography descriptors published to date, and test agreement on use of these terms, which was found to be low. Optical coherence tomography angiography (OCTA) has been used to identify and characterize macular neovascularization (MNV) secondary to age-related macular degeneration (AMD). 1-4 Many studies have explored OCTA morphological features of MNV that might serve as biomarkers to assess disease activity and response to treatment. 1-6 The proliferation of studies however has resulted in an OCTA terminology that has been variable and inconsistent. To address inconsistency ...
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  Mentions: Massachusetts Institute of Technology Medical University of Vienna Tufts University
9. Differential reperfusion patterns in retinal vascular plexuses following increase in intraocular pressure an OCT angiography study
  
  Explore Nature Publishing Group Oct 5 2020 Ophthalmology
  
  To describe patterns of reperfusion in the superficial vascular plexus (SVP), deep capillary plexus (DCP) and choriocapillaris (CC) as detected on optical coherence tomography (OCTA) in cynomogulus macaque monkey model following increase in intraocular pressure by an intravitreal injection. Animal imaging study. Two cynomogulus macaque monkeys. A 100 µL intravitreal injection (IVI) of saline was given in one eye of each monkey. Serial OCTA using a Zeiss Plex Elite 9000 was used to evaluate reperfusion patterns within the SCP, DCP, and CC. OCTA evidence of perfusion. Pulsation of the central retinal artery was detected after the intraocular pressure was elevated ...
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  Mentions: Singapore Eye Research Institute University of Sydney
10. The Varying Optical Coherence Tomography Appearance of the Inner Choroid with Age: Possible Explanation and Histologic Correlate
  
  Explore LWW Online Oct 4 2020 Ophthalmology
  
  Purpose: To investigate the reflectivity of the structural optical coherence tomography images of the inner choroid as it relates to potential structural composition. Methods: The reflectivity of slab images 29 – 49 µm and 45 – 65 µm below the RPE, obtained with the Zeiss Plex Elite 9000, were evaluated. The mean and standard deviation of a group of subjects with no ocular disorders were determined. Binarization of the images was done a threshold level established at the mean plus one standard deviation for each slab depth. The proportion of area binarized was evaluated with generalized estimating equations. Representative histologic images obtained ...
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11. NOVEL METHOD FOR IMAGE AVERAGING OF OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IMAGES
  
  Explore LWW Online Jul 1 2020 Ophthalmology
  
  Purpose: To develop a method of averaging optical coherence tomography (OCT) angiography to improve visualization of choriocapillaris structure. Methods: A stack of OCT angiographic data from vascular layers were placed into the red-green-blue channels of a conventional digital color image. The superficial plexus was placed in the blue channel, choriocapillaris in the green, and deep vascular plexus in the red channel. The red-green-blue images derived from nine separate OCT angiographic scans were registered using an automatic registration sequence and the images were averaged. The averaged red-green-blue image was then split into the three averaged component layers. The technique is flexible ...
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12. SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY IMAGE COMPENSATION OF THE CHORIOCAPILLARIS INDUCES ARTIFACTS
  
  Explore LWW Online May 27 2020 Ophthalmology
  
  Purpose: To analyze swept-source optical coherence angiography slab images acquired at the default level for the choriocapillaris from the Zeiss PLEX Elite 9000 before and after using a previously described imaging compensation technique. Methods: Eyes of normal subjects, in their 20 seconds and 30 seconds, were evaluated. Angiographic slab images, 20 µ m in thickness, were taken at the default location of 29 to 49 µ m below the retinal pigment epithelium. These images were evaluated, as were images that underwent a published compensation technique that adjusts for light penetration to the sampled layer. Each set of images was threshold at 1 ...
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13. Optical Coherence Tomography Angiography and Fluorescein Angiography Findings in Aminoglycoside Toxicity
  
  Explore LWW Online Apr 26 2020 Ophthalmology
  
  Photo essay
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14. Novel biomarker of sphericity and cylindricity indices in volume-rendering optical coherence tomography angiography in normal and diabetic eyes: a preliminary study
  
  Explore Home - Springer Jan 12 2020 Ophthalmology
  
  Purpose Preliminary to evaluate geometric indices (vessel sphericity and cylindricity) for volume-rendered optical coherence tomography angiography (OCTA) in healthy and diabetic eyes. Methods Twenty-six eyes of 13 healthy subjects and 12 eyes of patients with central ischemic, non-proliferative diabetic retinopathy were included. OCTA volume and surface area of the foveal vessels were measured and compared to determine OCTA sphericity and cylindricity indices and surface efficiency (SE). Results The overall average OCTA volume in healthy was 0.49 ± 0.09 mm 3 (standard deviation [SD]), compared to 0.44 ± 0.07 mm 3 (SD) in the diabetic eyes (difference in means ...
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  Mentions: University of Bonn
15. New Proposal For The Pathophysiology Of Type 3 Neovascularization As Based On Multimodal Imaging Findings
  
  Explore LWW Online Jul 24 2019 Ophthalmology
  
  Purpose: To investigate the imaging characteristics of early Type 3 neovascularization and propose a new pathophysiologic sequence for early disease. Methods: Patients were evaluated with a comprehensive ophthalmologic examination to include fundus photography, optical coherence tomography , optical coherence tomography angiography, fluorescein angiography, and volume-rendered optical coherence tomography angiography. Relevant literature was also reviewed. Results: There were 10 eyes of 9 patients who had a mean age of 87 (range 79–93) years and 7 were women. The patients were seen to have distributed areas of cystoid macular edema, not necessarily contiguous with areas of fluorescein or optical coherence tomography angiographic ...
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16. CHARACTERIZING RETINAL–CHOROIDAL ANASTOMOSIS IN MACULAR TELANGIECTASIA TYPE 2 WITH OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY
  
  Explore LWW Online Jul 6 2019 Ophthalmology
  
  Purpose: To characterize structural and angiographic findings in macular telangiectasia Type 2 (MacTel 2) and examine associations with visual acuity. Methods: MacTel 2 patients with complete ophthalmologic examination, including fundus photography, autofluorescence, spectral-domain optical coherence tomography, and projection-resolved optical coherence tomography angiography , were retrospectively evaluated. Results: There were 43 eyes of 22 patients with a mean age 63.9 (±10.3) years. Six patients had diabetes. Twenty-one eyes (48.8%) had retinal–choroidal anastomoses (RCAs) without any evidence of neovascularization extending laterally in a plane above or below the retinal pigment epithelium. None of the eyes had hemorrhage, lipid, or ...
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  Mentions: Columbia University
17. 3D printing of the choroidal vessels and tumours based on optical coherence tomography
  
  Explore Wiley Online Library Dec 14 2017 Ophthalmology
  
  The choroid has the highest blood flow of any structure in the human body...
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18. Enhanced resolution and speckle-free three-dimensional printing of macular optical coherence tomography angiography
  
  Explore Wiley Online Library Nov 13 2017 Ophthalmology
  
  No abstract provided
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  Mentions: University of Bonn
19. A Potential of Mechanism of Retinal Injury
  
  Explore LWW Online May 25 2017 Ophthalmology
  
  Purpose: To investigate the structural optical coherence tomography and related microvascular flow characteristics in eyes with retinal vasculitis. Methods: Regions involved with perivascular infiltration in eyes with retinal vasculitis, but no evidence of large vessel occlusion were evaluated with optical coherence tomography (OCT), OCT angiography, and fluorescein angiography. Results: Ten eyes of 5 patients with a variety of etiologies of retinal vasculitis were evaluated. These patients did not have either cotton wool spots or deeper placoid areas of retinal ischemia. Around large vessels there was perivascular infiltration with leakage and staining seen during fluorescein angiography. Structural OCT showed slight thickening ...
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20. Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography
  
  Explore ScienceDirect May 4 2017 Ophthalmology
  
  Purpose To describe a method to obtain images of the choroid using conventional spectral-domain (SD) optical coherence tomography (OCT) and to evaluate choroidal thickness measurements using these images. Design Observational case series. Methods The images were obtained by positioning the SD OCT device close enough to the eye to obtain an inverted representation of the fundus in healthy volunteers who did not have pupillary dilation. Seven sections, each comprised of 100 averaged scans, were obtained within a 5- × 15-degree rectangle centered on the fovea. The choroidal thickness under the fovea in each image was measured by independent observers. Results The ...
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  Mentions: LuEsther T. Mertz Retinal Research Center
21. Evaluation of Segmentation of the Superficial and Deep Vascular Layers of the Retina By Optical Coherence Tomography Angiography Instruments in Normal Eyes
  
  Explore The JAMA Network Jan 16 2017 Ophthalmology
  
  Importance Correct attribution of vascular features in optical coherence tomography (OCT) angiography depends on accurate segmentation of retinal layers. Objective To evaluate the segmentation of retinal layers among 3 OCT angiography instruments in the central macula, an area where the superficial and deep vascular plexuses terminate. Design, Setting, and Participants A retrospective review of a representative OCT angiogram from 1 patient and an evaluation of the vascular pattern in an autopsied eye were conducted at a community retina practice at a university laboratory. A set of 3 × 3-mm scans centered on the fovea using the Cirrus 5000, RTVue XR Avanti ...
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  Mentions: Optovue Topcon Medical Systems University of Alabama
22. VOLUME-RENDERED ANGIOGRAPHIC AND STRUCTURAL OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY OF MACULAR TELANGIECTASIA TYPE 2
  
  Explore LWW Online Oct 8 2016 Ophthalmology
  
  Purpose: To evaluate multimodal imaging including volume-rendered angiographic and structural optical coherence tomography of macular telangiectasia Type 2 (MacTel2) for right-angle vein complexes, macular cavitations, and signs of deeper retinal vascular invasion. Methods: Retrospective review of imaging performed in a community-based retinal referral center. The eyes were scanned using optical coherence tomography using split-spectrum amplitude-decorrelation techniques to derive flow information. These data were extracted and used to create volume-rendered images of the retinal vasculature with integrated structural information derived from the component optical coherence tomographic images. Results: There were 24 eyes of 16 patients who had a mean age of ...
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  Mentions: Columbia University LuEsther T. Mertz Retinal Research Center
23. Choroidal Findings in Eyes With Birdshot Chorioretinitis Using Enhanced-Depth Optical Coherence Tomography
  
  Explore IOVS Journal Sep 14 2016 Ophthalmology
  
  Purpose : The purposes of this study were to describe choroidal findings observed using optical coherence tomography with enhanced depth imaging (EDI-OCT) in eyes with birdshot chorioretinitis (BSCR) and to test the hypothesis that these findings are related to participant demographics, clinical characteristics, and treatment. Methods : In a multicenter, cross-sectional study, 172 eyes of 86 individuals with BSCR underwent a standardized clinical evaluation, including defined protocols for EDI-OCT imaging, with macular and peripapillary volume scans. Choroidal findings were compared to demographic information, ophthalmic examination findings, and treatment history, using logistic regression models. EDI-OCT images were evaluated by two independent, masked graders ...
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  Mentions: Johns Hopkins University Duke University Northwestern University
24. Volume Rendered Optical Coherence Tomography of Retinal Vein Occlusion Pilot Study
  
  Explore American Journal of Ophthalmology Mar 3 2016 Ophthalmology
  
  Purpose To investigate the retinal vascular findings and associated cystoid edema in the central macula of eyes with retinal vein occlusion using volume rendered angiographic and structural optical coherence tomography. Study Design Observational case series. Methods In this retrospective study 12 eyes of 12 consecutive patients, 3 with branch and 9 with central retinal vein occlusion were imaged in 27 sessions with optical coherence tomography (OCT) using split-spectrum amplitude decorrelation. The structural OCT data were segmented for cystoid spaces, and integrated into the angiographic data for subsequent volume rendering. The inner and deep vascular plexus were analyzed in relation to ...
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