1. Articles from Akihito Uji

    1-24 of 44 1 2 »
    1. Effect of image averaging on optical coherence tomography angiography data in eyes with branch retinal vein occlusion

      Effect of image averaging on optical coherence tomography angiography data in eyes with branch retinal vein occlusion

      Purpose To investigate the effect of image averaging on qualitative and quantitative assessments of optical coherence tomography angiography (OCTA) images from eyes of patients with branch retinal vein occlusion (BRVO). Methods Macular OCTA images of 33 eyes of 33 patients with BRVO were obtained using the HS100 HR-SD-OCT system (Canon, Inc.). For each eye, five OCTA cube scans were obtained with a 3 × 3 mm scan protocol, and the data were averaged and compounded into a single high image quality cube data using built-in software. Pre- and post-averaging images were compared qualitatively and quantitatively in superficial capillary plexus (SCP) and ...

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    2. Enhanced Visualization of Retinal Microvasculature in Optical Coherence Tomography Angiography Imaging via Deep Learning

      Enhanced Visualization of Retinal Microvasculature in Optical Coherence Tomography Angiography Imaging via Deep Learning

      Background: To investigate the effects of deep learning denoising on quantitative vascular measurements and the quality of optical coherence tomography angiography (OCTA) images. Methods: U-Net-based deep learning denoising with an averaged OCTA data set as teacher data was used in this study. One hundred and thirteen patients with various retinal diseases were examined. An OCT HS-100 (Canon inc., Tokyo, Japan) performed a 3 × 3 mm 2 superficial capillary plexus layer slab scan centered on the fovea 10 times. A single-shot image was defined as the original image and the 10-frame averaged image and denoised image generated from the original image ...

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    3. Usefulness of Denoising Process to Depict Myopic Choroidal Neovascularisation Using a Single Optical Coherence Tomography Angiography Image

      Usefulness of Denoising Process to Depict Myopic Choroidal Neovascularisation Using a Single Optical Coherence Tomography Angiography Image

      Quality of single optical coherence tomography angiography (OCTA) images of myopic choroidal neovascularisation (mCNV) is poorer than in averaged images, although obtaining averaged images takes much time. This study evaluated the clinical usefulness of novel denoising process for depicting mCNV. This study included 20 eyes of 20 patients with mCNV. Ten en face images taken in a 3 × 3 mm macular cube were obtained from outer-retina-to-choriocapillaris layer. Three image types were prepared for analysis; single images before and after the denoising process accomplished deep learning (single and denoising groups, respectively) and up to 10 images were averaged (averaging group). Pairwise ...

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    4. Angiographic Risk Features of Branch Retinal Vein Occlusion Onset as Determined by Optical Coherence Tomography Angiography

      Angiographic Risk Features of Branch Retinal Vein Occlusion Onset as Determined by Optical Coherence Tomography Angiography

      Purpose : Examine associations between the vasculature at arteriovenous (AV) crossings and the onset of branch retinal vein occlusion (BRVO). Methods : We included 78 patients with major BRVO, 35 patients with macular BRVO, and 110 controls without BRVO and determined the vessel positions at AV crossings, where the first- or second-order branches of the retinal veins associate, using a viewing angle of 12 × 12 mm 2 in optical coherence tomography angiography (OCTA). Results : We reviewed 1349 and 1276 AV crossings in BRVO patients and control subjects, respectively. The proportions of venous overcrossing were 26.5%, 28.6%, and 26.8% at ...

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    5. Disproportion of lamellar capillary non-perfusion in proliferative diabetic retinopathy on optical coherence tomography angiography

      Disproportion of lamellar capillary non-perfusion in proliferative diabetic retinopathy on optical coherence tomography angiography

      Purpose To characterise the non-perfused areas (NPAs) in the superficial and deep capillary layers (sNPAs and dNPAs, respectively) in the posterior pole in proliferative diabetic retinopathy (PDR) on wide-field optical coherence tomography angiography (OCTA) images. Methods We retrospectively reviewed 104 eyes of 70 patients with PDR from whom wide-field swept source OCTA images were acquired. sNPAs and dNPAs were manually measured in each quadrant of the inner (1–3 mm diameter), intermediate (3–6 mm), and outer (6–10 mm) rings centred on the fovea. Two qualitative findings, that is, segmented NPAs and periarteriolar NPAs , were also compared. Results The ...

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    6. In Vivo Mapping of the Choriocapillaris in Healthy Eyes: a Widefield Swept Source Optical Coherence Tomography Angiography Study

      In Vivo Mapping of the Choriocapillaris in Healthy Eyes: a Widefield Swept Source Optical Coherence Tomography Angiography Study

      Purpose To report variation of choriocapillaris (CC) flow in peripapillary, macular and near/mid periphery regions in healthy subjects using widefield swept source optical coherence tomography angiography (SS-OCTA). Design Prospective, cross-sectional study. Subjects Fifty healthy subjects. Methods Healthy young subjects were imaged with the SS-OCTA system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). OCTA scans were taken in primary and extremes of gaze and a montage was automatically created. The en face CC images were then exported to imageJ and a semi-automated algorithm was used for subsequent quantitative analysis. Main outcome measures Quantitative analysis of the CC ...

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    7. Optical coherence tomography risk factors for development of late age related macular degeneration in the fellow eyes of patients enrolled in the HARBOR Study

      Optical coherence tomography risk factors for development of late age related macular degeneration in the fellow eyes of patients enrolled in the HARBOR Study

      Purpose To evaluate the relationship between optical coherence tomography (OCT) features and the progression to late age related macular degeneration (AMD) in the fellow eyes of patients enrolled in the 24-month HARBOR study (NCT00891735) for neovascular AMD. Design post hoc analysis of a phase 3 multicenter, prospective, randomized, double-masked, active treatment-controlled clinical trial. Participants Evaluable subjects (N=501) with macular neovascularization (MNV) secondary to neovascular AMD and early or intermediate AMD in the fellow eye. Methods Volume OCT scans from 501 fellow eyes of 501 patients with MNV were reviewed. Baseline OCT features that were assessed included intraretinal hypereflective foci ...

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    8. 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 ...

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    9. A novel strategy for quantification of panoramic en face optical coherence tomography angiography scan field

      A novel strategy for quantification of panoramic en face optical coherence tomography angiography scan field

      Purpose To compare the retinal area measured on a panoramic en face optical coherence tomography angiography (OCTA) image with that on an ultra-widefield fluorescein angiography (UWF FA) image. Methods Sixteen eyes (11 with branch retinal vein occlusion, 2 with central retinal vein occlusion, 1 with branch retinal artery occlusion, and 2 with hypertensive retinopathy) were included in this study. A panoramic en face OCTA image was created from five single non-panoramic en face OCTA 12 × 12-mm images. The panoramic OCTA image was superimposed on the corresponding UWF FA image after image registration; the total retinal area was measured using the ...

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    10. Image processing apparatus, estimation method, system, and medium

      Image processing apparatus, estimation method, system, and medium

      The position of the fovea is estimated with high accuracy in a manner such that the thicknesses of a first region including at least a partial region of a region from the internal limiting membrane to the boundary between the external plexiform layer and the external granular layer and a second region including at least a partial region of a region from the boundary to the photoreceptor cell inner segment/outer segment junction are compared with each other, and the position of the fovea is estimated.

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    11. Concentric Choriocapillaris Flow Deficits in Retinitis Pigmentosa Detected Using Wide-Angle Swept-Source Optical Coherence Tomography Angiography

      Concentric Choriocapillaris Flow Deficits in Retinitis Pigmentosa Detected Using Wide-Angle Swept-Source Optical Coherence Tomography Angiography

      Purpose : We investigate whether choriocapillaris deficits can be visualized in patients with retinitis pigmentosa (RP) using wide-angle swept-source optical coherence tomography angiography (OCTA), and whether angiography or structure en face images depict a wider area of residual choriocapillaris. Methods : This cross-sectional study included 43 eyes of 43 consecutive patients with RP with a visual acuity ≥0.1, and 12 healthy eyes of 12 volunteers. Using an OCTA device (PLEX Eite 9000), we obtained angiography and structure en face images in the choriocapillaris. The residual choriocapillaris area in a 12 × 12 mm macular cube was measured manually. Results : In patients with ...

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    12. Pearls and Pitfalls of Optical Coherence Tomography Angiography Imaging: A Review

      Pearls and Pitfalls of Optical Coherence Tomography Angiography Imaging: A Review

      Optical coherence tomography angiography (OCTA) has significantly expanded our knowledge of the ocular vasculature. Furthermore, this imaging modality has been widely adopted to investigate different ocular and systemic diseases. In this review, a discussion of the fundamental principles of OCTA is followed by the application of this imaging modality to study the retinal and choroidal vessels. A proper comprehension of this imaging modality is essential for the interpretation of OCTA imaging applications in retinal and choroidal disorders.

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    13. One-Year Outcome Predictors of Strabismus Surgery from Anterior Segment Optical Coherence Tomography with Multiple B-Scan Averaging

      One-Year Outcome Predictors of Strabismus Surgery from Anterior Segment Optical Coherence Tomography with Multiple B-Scan Averaging

      Strabismologists are eager to identify preoperative or intraoperative strabismus surgery outcome predictors because of the variable effects in each patient. Conjunctival closure position recession after rectus muscle recession is effective for correcting large angle strabismus. The elasticity of the conjunctiva and Tenon’s capsule is important for strabismus surgery management. In this longitudinal study, we evaluated the prognosis of conjunctiva and Tenon’s capsule thickness (CTT) near the limbus 1 year after strabismus surgery with a limbal conjunctival incision using swept-source anterior segment optical coherence tomography with multiple B-scan averaging. Also, we identified preoperative and/or intraoperative parameters associated with ...

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    14. Segmentation of the Four-Layered Retinal Vasculature Using High-Resolution Optical Coherence Tomography Angiography Reveals the Microcirculation Unit

      Segmentation of the Four-Layered Retinal Vasculature Using High-Resolution Optical Coherence Tomography Angiography Reveals the Microcirculation Unit

      Purpose : To differentiate the four layers of the retinal vessel network in the human macula and examine their morphologic features using high-resolution optical coherence tomography angiography (HR-OCTA). Methods : Macular areas measuring 464 × 464 pixels of 10 right eyes of 10 healthy subjects without ocular disease were scanned 10 times using a HR-OCTA device. Averaged OCTA images were created. Based on clear decorrelation signals, four vascular slabs were segmented, comprising one each in the retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and top and bottom of the inner nuclear layer (INL). Qualitative features and quantitative measurements in each slab ...

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    15. Anterior Segment Optical Coherence Tomography Angiography in a Patient With Persistent Pupillary Membrane

      Anterior Segment Optical Coherence Tomography Angiography in a Patient With Persistent Pupillary Membrane

      The image depicts a 60-year-old woman with bilateral cataracts and no history of amblyopia, strabismus, or systemic diseases. Color slitlamp photography of the left eye ( Figure , A) showed a persistent pupillary membrane, with multiple iris strands extending from collarette to collarette and adhering to the anterior lens surface. Anterior segment optical coherence tomography angiography ( Figure , B) showed vessels originating from the lesser arterial circle of the iris and anastomosing with one another centrally. Persistent pupillary membrane results from incomplete involution of the tunica vasculosa lentis, which supplies the epithelium of the lens during fetal development. 1

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    16. Visualization of the Lamina Cribrosa Microvasculature in Normal and Glaucomatous Eyes: A Swept-source Optical Coherence Tomography Angiography Study

      Visualization of the Lamina Cribrosa Microvasculature in Normal and Glaucomatous Eyes: A Swept-source Optical Coherence Tomography Angiography Study

      Purpose: The purpose of this study was to investigate the lamina cribrosa (LC) microvasculature using swept-source (SS) optical coherence tomography angiography (OCTA) images that have been processed using multiple image averaging and a projection-resolved algorithm. OCTA has recently gained popularity for assessing retinal and choroidal microvasculature . However, it is not known if the LC microvasculature , which likely holds important information for further understanding of glaucoma , can be visualized with OCTA. Methods: One normal subject and one glaucomatous subject were enrolled and optic disc 3×3▒mm SS-OCTA cubic images were obtained for each subject. Anterior LC slab frames were developed ...

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    17. Choriocapillaris impairment around the atrophic lesions in patients with geographic atrophy: a swept-source optical coherence tomography angiography study

      Choriocapillaris impairment around the atrophic lesions in patients with geographic atrophy: a swept-source optical coherence tomography angiography study

      Aims To evaluate the choriocapillaris (CC) flow alterations around geographic atrophy (GA) in eyes with dry age-related macular degeneration. Methods Using a swept-source optical coherence tomography angiography (SS-OCTA) device, two volume 6×6 mm scans were acquired in patients with GA presenting between June and December 2017 at the Doheny-UCLA Eye Centers. The area of GA was delineated on the en face structural OCT fundus images. For each eye, the en face OCTA slabs at the level of the CC from the two acquisitions were averaged and compensated for signal loss using the corresponding structural en face images. The resulting ...

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    18. Conjunctival and Intrascleral Vasculatures Assessed Using Anterior-Segment Optical Coherence Tomography Angiography in Normal Eyes

      Conjunctival and Intrascleral Vasculatures Assessed Using Anterior-Segment Optical Coherence Tomography Angiography in Normal Eyes

      Purpose To investigate conjunctival and intrascleral vasculatures using anterior-segment (AS) optical coherence tomography angiography (OCTA) in normal eyes. Design Cross-sectional study. Methods AS-OCTA images of the corneal limbus were acquired circumferentially using a swept-source OCT system in 10 eyes of 10 healthy subjects. AS-OCTA flow patterns with en face maximum projection were compared between 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 OCTA images were also compared with fluorescein scleral angiography and indocyanine green aqueous angiography images. Quantitative parameters (vessel density, vessel length ...

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    19. Lacrimal Canaliculus Imaging Using Optical Coherence Tomography Dacryography

      Lacrimal Canaliculus Imaging Using Optical Coherence Tomography Dacryography

      Lacrimal canaliculus (LC) has a key role in tear drainage, but it is difficult to evaluate the LC in detail, using the existing examinations. In this study, our novel LC imaging technique provided the high-resolution images of LC in a non-invasive manner. Three-dimensional images of LC were acquired via the palpebral conjunctiva from 20 healthy volunteers (20 eyes) and 10 patients with various lacrimal disorders (10 eyes), using optical coherence tomography (OCT) dacryography (OCTD). The LC images showed morphological differences between the vertical and horizontal segments. The function of LC could be evaluated by measuring the intralumen signal intensity over ...

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    20. Pilot study assessing the structural changes in posttrabecular aqueous humor outflow pathway after trabecular meshwork surgery using swept-source optical coherence tomography

      Pilot study assessing the structural changes in posttrabecular aqueous humor outflow pathway after trabecular meshwork surgery using swept-source optical coherence tomography

      This study evaluated the morphological change in aqueous humor outflow (AHO) pathways using swept-source optical coherence tomography (SS-OCT) volumetric scans in glaucoma patients before and after glaucoma surgery. In this prospective observational case series, 15 eyes (13 patients) with glaucoma were treated with 120-degree Trabectome or 360-degree suture trabeculotomy and followed up for 3 months. B-scan images of the posttrabecular AHO pathway were reconstructed and the pathway areas were evaluated, before and after surgery. Changes in posttrabecular AHO pathway were qualitatively classified as “increased”, “non-significant change”, and “decreased” on reconstructed B-scan images. Quantitative measurements of the posttrabecular AHO pathway areas ...

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    21. Systems, methods, and devices for optical coherence tomography multiple enface angiography averaging

      Systems, methods, and devices for optical coherence tomography multiple enface angiography averaging

      The disclosure herein provides methods, systems, and devices for improving optical coherence tomography machine outputs through multiple enface optical coherence tomography angiography averaging techniques. The embodiments disclosed herein can be utilized in ophthalmology for employing optical coherence tomography (OCT) for in vivo visualization of blood vessels and the flow of blood in an eye of a patient, which is also known generally as optical coherence tomography angiography (OCTA). The embodiments disclosed herein can use linear registration, affine registration and/or elastic registration to align a plurality of optical coherence tomography angiography images or videos at corresponding superficial vascular layers having ...

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    22. Systems, methods, and devices for optical coherence tomography multiple enface angiography averaging

      Systems, methods, and devices for optical coherence tomography multiple enface angiography averaging

      Abstract The disclosure herein provides methods, systems, and devices for improving optical coherence tomography machine outputs through multiple enface optical coherence tomography angiography averaging techniques. The embodiments disclosed herein can be utilized in ophthalmology for employing optical coherence tomography (OCT) for in vivo visualization of blood vessels and the flow of blood in an eye of a patient, which is also known generally as optical coherence tomography angiography (OCTA). The embodiments disclosed herein can use linear registration, affine registration and/or elastic registration to align a plurality of optical coherence tomography angiography images or videos at corresponding superficial vascular layers ...

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    23. Multiple enface image averaging for enhanced optical coherence tomography angiography imaging

      Multiple enface image averaging for enhanced optical coherence tomography angiography imaging

      Purpose To investigate the effect of multiple enface image averaging on image quality of the optical coherence tomography angiography (OCTA). Methods Twenty‐one normal volunteers were enrolled in this study. For each subject, one eye was imaged with 3 × 3 mm scan protocol, and another eye was imaged with the 6 × 6 mm scan protocol centred on the fovea using the ZEISS Angioplex™ spectral‐domain OCTA device. Eyes were repeatedly imaged to obtain nine OCTA cube scan sets, and nine superficial capillary plexus (SCP) and deep capillary plexus (DCP) were individually averaged after registration. Results Eighteen eyes with a 3 ...

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    24. Repeatability and Reproducibility of Superficial Macular Retinal Vessel Density Measurements Using Optical Coherence Tomography Angiography En Face Images

      Repeatability and Reproducibility of Superficial Macular Retinal Vessel Density Measurements Using Optical Coherence Tomography Angiography En Face Images

      Importance The repeatability and reproducibility of quantitative metrics from optical coherence tomographic angiography (OCTA) must be assessed before these data can be confidently interpreted in clinical research and practice. Objective To evaluate the repeatability and reproducibility of OCTA-derived retinal vascular quantitative metrics. Design, Setting and Participants In this cross-sectional study, 21 healthy volunteers (42 eyes) and 22 patients with retinal disease (22 eyes), including 14 with age-related macular degeneration, 3 with epiretinal membrane, 2 with diabetic retinopathy, 2 with myopic macular degeneration, and 1 with retinal vein occlusion, were enrolled. Participants were recruited from September 1 through November 31, 2016 ...

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