1. Articles from Yali Jia

    1-24 of 120 1 2 3 4 5 »
    1. 105° field of view non-contact handheld swept-source optical coherence tomography

      105° field of view non-contact handheld swept-source optical coherence tomography

      We demonstrate a handheld swept-source optical coherence tomography (OCT) system with a 400 kHz vertical-cavity surface-emitting laser (VCSEL) light source, a non-contact approach, and an unprecedented single shot 105° field of view (FOV). We also implemented a spiral scanning pattern allowing real-time visualization with improved scanning efficiency. To the best of our knowledge, this is the widest FOV achieved in a portable non-contact OCT retinal imaging system to date. Improvements to the FOV may aid the evaluation of retinal diseases such as retinopathy of prematurity, where important vitreoretinal changes often occur in the peripheral retina.

      Read Full Article
    2. Deep learning-based signal-independent assessment of macular avascular area on 6×6 mm optical coherence tomography angiogram in diabetic retinopathy: a comparison to instrument-embedded software

      Deep learning-based signal-independent assessment of macular avascular area on 6×6 mm optical coherence tomography angiogram in diabetic retinopathy: a comparison to instrument-embedded software

      Synopsis: A deep-learning-based macular extrafoveal avascular area (EAA) on a 6×6 mm optical coherence tomography (OCT) angiogram is less dependent on the signal strength and shadow artefacts, providing better diagnostic accuracy for diabetic retinopathy (DR) severity than the commercial software measured extrafoveal vessel density (EVD). Aims: To compare a deep-learning-based EAA to commercial output EVD in the diagnostic accuracy of determining DR severity levels from 6×6 mm OCT angiography (OCTA) scans. Methods: The 6×6 mm macular OCTA scans were acquired on one eye of each participant with a spectral-domain OCTA system. After excluding the central 1 mm ...

      Read Full Article
    3. Optical coherence tomographic angiography study of perfusion recovery after surgical lowering of intraocular pressure

      Optical coherence tomographic angiography study of perfusion recovery after surgical lowering of intraocular pressure

      We investigated the time and location of retinal perfusion recovery after surgical intraocular pressure (IOP) lowering in glaucoma by using optical coherent tomography angiography (OCTA). Seventeen patients were analyzed. The 4.5 × 4.5-mm OCTA scans centered on the disc were performed preoperatively and postoperatively at 6 weeks, 3 months, and 6 months. The peripapillary retinal nerve fiber layer (NFL) thickness, NFL plexus capillary density (NFLP-CD) and visual field (VF) were measured overall and in 8 corresponding sectors. The low-perfusion area (LPA) was used to assess the cumulative area where local NFLP-CD was significantly below normal. At 6 months, the ...

      Read Full Article
    4. Normative intercapillary distance and vessel density data in the temporal retina assessed by wide-field spectral-domain optical coherence tomography angiography

      Normative intercapillary distance and vessel density data in the temporal retina assessed by wide-field spectral-domain optical coherence tomography angiography

      A limitation of conventional optical coherence tomography angiography (OCTA) is the limited field of view normally used in data acquisition. As the technology improves, larger fields of view that capture information away from the macular are being explored in order to provide an enhanced ability to detect pathology. However, normative measurements for important OCTA metrics like vessel density and intercapillary distance are not currently well-characterized in the peripheral retina. In this prospective study, we measured vessel density and intercapillary distance of the superficial vascular complex, ganglion cell layer plexus, and deep capillary plexus in montaged macular/temporal scans from 53 ...

      Read Full Article
    5. Effect of algorithms and covariates in glaucoma diagnosis with optical coherence tomography angiography

      Effect of algorithms and covariates in glaucoma diagnosis with optical coherence tomography angiography

      Purpose: To assess the effects of algorithms and covariates in glaucoma diagnosis with optical coherence tomography angiography (OCTA). Methods: In this prospective cross-sectional study, one eye each of 36 normal controls and 64 patients with glaucoma underwent 4.5 mm disc-centred and 6 mm macula-centred OCTA scans. The peripapillary nerve fibre layer plexus capillary density (NFLP-CD) and macular superficial vascular complex vessel density (SVC-VD) were measured using both a commercial algorithm (AngioAnalytics) and a custom algorithm (Center for Ophthalmic Optics & Lasers Angiography Reading Toolkit (COOL-ART)). The nerve fibre layer and ganglion cell complex thicknesses were measured on structural OCT. Results ...

      Read Full Article
    6. DcardNet: Diabetic Retinopathy Classification at Multiple Levels Based on Structural and Angiographic Optical Coherence Tomography

      DcardNet: Diabetic Retinopathy Classification at Multiple Levels Based on Structural and Angiographic Optical Coherence Tomography

      Objective: Optical coherence tomography (OCT) and its angiography (OCTA) have several advantages for the early detection and diagnosis of diabetic retinopathy (DR). However, automated, complete DR classification frameworks based on both OCT and OCTA data have not been proposed. In this study, a convolutional neural network (CNN) based method is proposed to fulfill a DR classification framework using en face OCT and OCTA.

      Read Full Article
    7. Cognitive decline in older adults: What can we learn from optical coherence tomography (OCT)-based retinal vascular imaging?

      Cognitive decline in older adults: What can we learn from optical coherence tomography (OCT)-based retinal vascular imaging?

      Introduction: Accumulated vascular damage contributes to the onset and progression of vascular dementia and possibly to Alzheimer's disease. Here we evaluate the feasibility and utility of using retinal imaging of microvascular markers to identify older adults at risk of cognitive disease. Methods: The "Eye Determinants of Cognition" (EyeDOC) study recruited a biracial, population-based sample of participants from two sites: Jackson, MS, and Washington Co, MD. Optical coherence tomographic angiography (OCTA) was used to capture vessel density (VD) from a 6 × 6 mm scan of the macula in several vascular layers from 2017 to 2019. The foveal avascular zone (FAZ ...

      Read Full Article
    8. High-speed and widefield handheld swept-source OCT angiography with a VCSEL light source

      High-speed and widefield handheld swept-source OCT angiography with a VCSEL light source

      Optical coherence tomography (OCT) and OCT angiography (OCTA) enable noninvasive structural and angiographic imaging of the eye. Portable handheld OCT/OCTA systems are required for imaging patients in the supine position. Examples include infants in the neonatal intensive care unit (NICU) and operating room (OR). The speed of image acquisition plays a pivotal role in acquiring high-quality OCT/OCTA images, particularly with the handheld system, since both the operator hand tremor and subject motion can cause significant motion artifacts. In addition, having a large field of view and the ability of real-time data visualization are critical elements in rapid disease ...

      Read Full Article
    9. Phase-stabilized complex-decorrelation angiography

      Phase-stabilized complex-decorrelation angiography

      In this study, we developed a novel phase-stabilized complex-decorrelation (PSCD) optical coherence tomography (OCT) angiography (OCTA) method that can generate high quality OCTA images. This method has been validated using three different types of OCT systems and compared with conventional complex- and amplitude-based OCTA algorithms. Our results suggest that in combination with a pre-processing phase stabilization method, the PSCD method is insensitive to bulk motion phase shifts, less dependent on OCT reflectance than conventional complex methods and demonstrates extended dynamic range of flow signal, in contrast to other two methods.

      Read Full Article
    10. Comparison of Central Macular Fluid Volume With Central Subfield Thickness in Patients With Diabetic Macular Edema Using Optical Coherence Tomography Angiography

      Comparison of Central Macular Fluid Volume With Central Subfield Thickness in Patients With Diabetic Macular Edema Using Optical Coherence Tomography Angiography

      Importance: Diabetic macular edema (DME) is the predominant cause of visual impairment in patients with type 1 or 2 diabetes. Automated fluid volume measurements using optical coherence tomography (OCT) may improve the diagnostic accuracy of DME screening. Objective: To assess the diagnostic accuracy of an automated central macular fluid volume (CMFV) quantification using OCT for DME. Design, setting, and participants: A cross-sectional observational study was conducted at a tertiary academic center among 215 patients with diabetes (1 eye each) enrolled from January 26, 2015, to December 23, 2019. All participants underwent comprehensive examinations, 6 × 6-mm macular structural OCT horizontal raster ...

      Read Full Article
    11. Plexus-specific retinal vascular anatomy and pathologies as seen by projection-resolved optical coherence tomographic angiography

      Plexus-specific retinal vascular anatomy and pathologies as seen by projection-resolved optical coherence tomographic angiography

      Optical coherence tomographic angiography (OCTA) is a novel technology capable of imaging retinal vasculature three-dimensionally at capillary scale without the need to inject any extrinsic dye contrast. However, projection artifacts cause superficial retinal vascular patterns to be duplicated in deeper layers, thus interfering with the clean visualization of some retinal plexuses and vascular pathologies. Projection-resolved OCTA (PR-OCTA) uses post-processing algorithms to reduce projection artifacts. With PR-OCTA, it is now possible to resolve up to 4 distinct retinal vascular plexuses in the living human eye. The technology also allows us to detect and distinguish between various retinal and optic nerve diseases ...

      Read Full Article
    12. Plexus-specific retinal capillary avascular area in exudative age-related macular degeneration with projection-resolved OCT angiography

      Plexus-specific retinal capillary avascular area in exudative age-related macular degeneration with projection-resolved OCT angiography

      Objective To detect the plexus-specific retinal capillary avascular area in exudative age-related macular degeneration (EAMD) with projection-resolved optical coherence tomography angiography (PR-OCTA). Methods and analysis In this prospective cross-sectional single centre study, eyes with treatment-naïve EAMD underwent macular 3×3 mm OCTA with AngioVue system. OCTA scans were analysed and processed including three-dimensional projection artefact removal, retinal layer semi-automated segmentation and en face angiogram generation. Automated quantification of extrafoveal (excluding the central 1 mm circle) avascular area (EAA) were calculated on projection-resolved superficial vascular complex (SVC), intermediate capillary plexus (ICP) and deep capillary plexus (DCP), respectively. Results Nineteen eyes ...

      Read Full Article
    13. Split-spectrum amplitude-decorrelation angiography with optical coherence tomography

      Split-spectrum amplitude-decorrelation angiography with optical coherence tomography

      Amplitude decorrelation measurement is sensitive to transverse flow and immune to phase noise in comparison to Doppler and other phase-based approaches. However, the high axial resolution of OCT makes it very sensitive to the pulsatile bulk motion noise in the axial direction. To overcome this limitation, we developed split-spectrum amplitude-decorrelation angiography (SSADA) to improve the signal-to-noise ratio (SNR) of flow detection. The full OCT spectrum was split into several narrower bands. Inter-B-scan decorrelation was computed using the spectral bands separately and then averaged. The SSADA algorithm was tested on in vivo images of the human macula and optic nerve head ...

      Read Full Article
    14. Sensorless adaptive-optics optical coherence tomographic angiography

      Sensorless adaptive-optics optical coherence tomographic angiography

      Optical coherence tomographic angiography (OCTA) can image the retinal blood flow but visualization of the capillary caliber is limited by the low lateral resolution. Adaptive optics (AO) can be used to compensate ocular aberrations when using high numerical aperture (NA), and thus improve image resolution. However, previously reported AO-OCTA instruments were large and complex, and have a small sub-millimeter field of view (FOV) that hinders the extraction of biomarkers with clinical relevance. In this manuscript, we developed a sensorless AO-OCTA prototype with an intermediate numerical aperture to produce depth-resolved angiograms with high resolution and signal-to-noise ratio over a 2 × 2 ...

      Read Full Article
    15. Automated segmentation of retinal fluid volumes from structural and angiographic optical coherence tomography using deep learning

      Automated segmentation of retinal fluid volumes from structural and angiographic optical coherence tomography using deep learning

      Purpose: We proposed a deep convolutional neural network (CNN), named Retinal Fluid Segmentation Network (ReF-Net) to segment volumetric retinal fluid on optical coherence tomography (OCT) volume. Methods: 3 × 3-mm OCT scans were acquired on one eye by a 70-kHz OCT commercial AngioVue system (RTVue-XR; Optovue, Inc.) from 51 participants in a clinical diabetic retinopathy (DR) study (45 with retinal edema and 6 healthy controls). A CNN with U-Net-like architecture was constructed to detect and segment the retinal fluid. Cross-sectional OCT and angiography (OCTA) scans were used for training and testing ReF-Net. The effect of including OCTA data for retinal fluid ...

      Read Full Article
    16. Retinal capillary oximetry with visible light optical coherence tomography

      Retinal capillary oximetry with visible light optical coherence tomography

      Assessing oxygen saturation (sO 2 ) remains challenging but is nonetheless necessary for understanding retinal metabolism. We and others previously achieved oximetry on major retinal vessels and measured the total retinal oxygen metabolic rate in rats using visible-light optical coherence tomography. Here we extend oximetry measurements to capillaries and investigate all three retinal vascular plexuses by amplifying and extracting the spectroscopic signal from each capillary segment under the guidance of optical coherence tomography (OCT) angiography. Using this approach, we measured capillary sO 2 in the retinal circulation in rats, demonstrated reproducibility of the results, validated the measurements in superficial capillaries with ...

      Read Full Article
    17. Depth-resolved optimization of a real-time sensorless adaptive optics optical coherence tomography

      Depth-resolved optimization of a real-time sensorless adaptive optics optical coherence tomography

      Sensorless adaptive optics optical coherence tomography (AO-OCT) is a technology to image retinal tissue with high resolution by compensating ocular aberrations without wavefront sensors. In this Letter, a fast and robust hill-climbing algorithm is developed to optimize five Zernike modes in AO-OCT with a numerical aperture between that of conventional AO and commercial OCT systems. The merit function is generated in real time using graphics processing unit while axially tracking the retinal layer of interest. A new method is proposed to estimate the largest achievable field of view for which aberrations are corrected uniformly in sensorless AO-OCT.

      Read Full Article
    18. Optical coherence tomography angiography avascular area association with one-year treatment requirement and disease progression in diabetic retinopathy

      Optical coherence tomography angiography avascular area association with one-year treatment requirement and disease progression in diabetic retinopathy

      Purpose To assess the association between optical coherence tomography angiography (OCTA) quantified avascular areas (AA) and diabetic retinopathy (DR) severity, progression and treatment requirement in the following year. Design Prospective cohort study. Methods We recruited diabetic patients from tertiary academic retina practice and obtained 3x3-mm macular OCTA scans with AngioVue system and standard 7-field color photographs at baseline and 1-year visit. A masked grader determined the DR severity from the color photographs using the Early Treatment of Diabetic Retinopathy (ETDRS) scale. A custom algorithm detected extrafoveal AA (EAA) excluding the central 1mm circle in projection-resolved superficial vascular complex (SVC), intermediate ...

      Read Full Article
    19. Systems and methods to remove shadowgraphic flow projections on OCT angiography

      Systems and methods to remove shadowgraphic flow projections on OCT angiography

      Methods and systems for suppressing shadowgraphic flow projection artifacts in OCT angiography images of a sample are disclosed. In one example approach, normalized OCT angiography data is analyzed at the level of individual A-scans to classify signals as either flow or projection artifact. This classification information is then used to suppress projection artifacts in the three dimensional OCT angiography dataset.

      Read Full Article
    20. Imaging retinal structures at cellular-level resolution by visible-light optical coherence tomography

      Imaging retinal structures at cellular-level resolution by visible-light optical coherence tomography

      In vivo high-resolution images are the most direct way to understand retinal function and diseases. Here we report the use of visible-light optical coherence tomography with volumetric registration and averaging to achieve cellular-level retinal structural imaging in a rat eye, covering the entire depth of the retina. Vitreous fibers, nerve fiber bundles, and vasculature were clearly revealed, as well as at least three laminar sublayers in the inner plexiform layer. We also successfully visualized ganglion cell somas in the ganglion cell layer, cells in the inner nuclear layer, and photoreceptors in the outer nuclear layer and ellipsoid zone. This technique ...

      Read Full Article
    21. Application of Corneal Optical Coherence Tomography Angiography for Assessment of Vessel Depth in Corneal Neovascularization

      Application of Corneal Optical Coherence Tomography Angiography for Assessment of Vessel Depth in Corneal Neovascularization

      Purpose: To map and measure the depths of corneal neovascularization (NV) using 3-dimensional optical coherence tomography angiography (OCTA) at 2 different wavelengths. Methods: Corneal NV of varying severity, distribution, and underlying etiology was examined. Average NV depth and vessel density were measured using 840-nm spectral-domain OCTA and 1050-nm swept-source OCTA. The OCTA results were compared with clinical slit-lamp estimation of NV depth. Results: Twelve eyes with corneal NV from 12 patients were imaged with OCTA. Clinically “superficial,” “midstromal,” and “deep” cases had an average vessel depth of 23%, 39%, and 66% on 1050-nm OCTA, respectively. Average vessel depth on OCTA ...

      Read Full Article
    22. Sectorwise Visual Field Simulation Using Optical Coherence Tomographic Angiography Nerve Fiber Layer Plexus Measurements in Glaucoma

      Sectorwise Visual Field Simulation Using Optical Coherence Tomographic Angiography Nerve Fiber Layer Plexus Measurements in Glaucoma

      Purpose To simulate 24-2 visual field (VF) using optical coherence tomographic angiography (OCTA) for glaucoma evaluation. Design Cross-sectional study. Methods One eye each of 39 glaucoma and 31 age-matched normal participants was scanned using 4.5-mm OCTA scans centered on the disc. The peripapillary retinal nerve fiber layer plexus capillary density (NFLP_CD, %area) was measured. The NFLP_CD and 24-2 VF maps were divided into 8 corresponding sectors using an extension of Garway-Heath scheme. Results Sector NFLP_CD was transformed to a logarithmic dB scale and converted to sector simulated VF deviation maps. Comparing simulated and actual 24-2 VF maps, the worst ...

      Read Full Article
    23. Quantification of local circulation with OCT angiography

      Quantification of local circulation with OCT angiography

      Impaired intraocular blood flow within vascular beds in the human eye is associated with certain ocular diseases including, for example, glaucoma, diabetic retinopathy and age-related macular degeneration. A reliable method to quantify blood flow in the various intraocular vascular beds could provide insight into the vascular component of ocular disease pathophysiology. Using ultrahigh-speed optical coherence tomography (OCT), a new 3D angiography algorithm called split-spectrum amplitude-decorrelation angiography (SSADA) was developed for imaging microcirculation within different intraocular regions. A method to quantify SSADA results was developed and used to detect perfusion changes in early stage ocular disease. Associated embodiments relating to methods ...

      Read Full Article
    24. Measuring Glaucomatous Focal Perfusion Loss in the Peripapillary Retina using Optical Coherence Tomographic Angiography

      Measuring Glaucomatous Focal Perfusion Loss in the Peripapillary Retina using Optical Coherence Tomographic Angiography

      Purpose To measure low perfusion areas (LPA) and focal perfusion loss (FPL) in the peripapillary retina using optical coherence tomographic angiography (OCTA) in glaucoma. Design Prospective observation study. Participants Forty-seven primary open angle glaucoma (POAG) patients and 36 normal subjects were analyzed. Methods One eye of each subject was scanned using AngioVue 4.5-mm OCTA scan centered on the disc. En face nerve fiber layer plexus angiogram was generated. Using custom software, capillary density map was obtained by computing the fraction of area occupied by flow pixels within each superpixel containing 21×21-pixels. The low-perfusion map is defined by local ...

      Read Full Article
    1-24 of 120 1 2 3 4 5 »
  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
  2. Topics in the News

    1. (116 articles) Oregon Health & Science University
    2. (94 articles) Center for Ophthalmic Optics and Lasers
    3. (13 articles) Massachusetts Institute of Technology
    4. (10 articles) Optovue
    5. (5 articles) University of Erlangen
    6. (5 articles) University of Washington
    7. (4 articles) National Institutes of Health
    8. (4 articles) Thorlabs
    9. (3 articles) Simon Fraser University
    10. (3 articles) University of Southern California
    11. (1 articles) University of Iowa
    12. (1 articles) Medical University of Vienna
    13. (1 articles) Johns Hopkins University
    14. (1 articles) Duke University
    15. (1 articles) University College London
    16. (1 articles) Topcon Medical Systems
    17. (1 articles) Lumedica
  3. Popular Articles

  4. Picture Gallery

    Doppler optical microangiography improves the quantification of local fluid flow and shear stress within 3-D porous constructs The study of effects of pore architecture in chitosan scaffolds on the fluid flow pattern by Doppler OCT High sensitive volumetric imaging of renal microcirculation in vivo using ultrahigh sensitive optical microangiography Highly sensitive imaging of renal microcirculation in vivo using ultrahigh sensitive optical microangiography Split-spectrum amplitude-decorrelation angiography with optical coherence tomography Clinical Guide to Angio-OCT (Non Invasive, Dyeless OCT Angiography)  (Textbook) Clinical OCT Angiography Atlas (Textbook) Post-doctoral fellowship in Optical Coherence Tomography at Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA Investigation of Light Parameters on Image Quality and Optical Coherence Tomography Potential Utility of Adjunct Imaging with Wide-Field Optical Coherence Tomography for Gross and Microscopic Evaluation of Breast Specimens in Real-Time in the Operating Suite Denoising Swept Source Optical Coherence Tomography Volumetric Scans using a Deep Learning Model Optical coherence tomography in multiple sclerosis: A 3-year prospective multicenter study