All Articles from Tadamichi Akagi -Optical Coherence Tomography News

Articles from Tadamichi Akagi

1-24 of 38 1 2 »
1. Image Evaluation Of Artificial Intelligence Supported Optical Coherence Tomography Angiography Imaging Using OCT-HS100 Device In Diabetic Retinopathy
  
  Explore LWW Online Jan 7 2021 Ophthalmology
  
  Purpose: To investigate the effect of denoise processing by artificial intelligence (AI) on the optical coherence tomography angiography (OCTA) images in eyes with retinal lesions. Methods: Prospective, observational, cross-sectional study. OCTA imaging of a 3 x 3 mm area involving the lesions (neovascularization, intraretinal microvascular abnormality, and non-perfusion area) was performed five times using OCT-HS100 (Canon, Tokyo, Japan). We acquired AI-denoised OCTA images and averaging OCTA images generated from five cube scan data via built-in software. Main outcomes were image acquisition time and the subjective assessment by graders and quantitative measurements of original OCTA images, averaging OCTA images, and AI-denoised ...
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  Mentions: Akitaka Tsujikawa Kyoto University Graduate School of Medicine Tadamichi Akagi
2. Short-Term Effects of Different Types of Anti-Glaucoma Eyedrop on the Sclero-Conjunctival Vasculature Assessed Using Anterior Segment OCTA in Normal Human Eyes: A Pilot Study
  
  Explore MDPI Open Access Journals Platform Dec 11 2020 Ophthalmology
  
  Background: To investigate the short-term effects of different types of anti-glaucoma eyedrop on sclero-conjunctival vasculatures and their associations with intraocular pressure (IOP) reduction. Methods: This was a prospective study including 20 healthy subjects. A single instillation of ripasudil or bimatoprost was introduced into the right eyes of the participants. The superficial (conjunctival) and deep (intrascleral) vasculatures of the corneal limbus using anterior-segment optical coherence tomography angiography (OCTA) and IOP were examined in both eyes at baseline and 15 min and 2 h after instillation. Results: In the ripasudil group, the vessel density (VD) (median) at baseline (deep, 13.1%; superficial ...
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  Mentions: Akitaka Tsujikawa Kyoto University Graduate School of Medicine Tadamichi Akagi
3. Effect of image averaging on optical coherence tomography angiography data in eyes with branch retinal vein occlusion
  
  Explore Home - Springer May 3 2020 Ophthalmology
  
  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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  Mentions: Srinivas R. Sadda Akitaka Tsujikawa UCLA
4. Enhanced Visualization of Retinal Microvasculature in Optical Coherence Tomography Angiography Imaging via Deep Learning
  
  Explore MDPI Open Access Journals Platform May 2 2020 Ophthalmology
  
  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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  Mentions: Akitaka Tsujikawa Kyoto University Graduate School of Medicine Tadamichi Akagi
5. Anterior Segment Optical Coherence Tomography Angiography of Iris Neovascularization After Intravitreal Ranibizumab and Panretinal Photocoagulation
  
  Explore The JAMA Network Feb 14 2020 Ophthalmology
  
  A 58-year-old Japanese man with diabetes presented with blurred vision in his right eye. His intraocular pressure was 53 mm Hg and the peripheral anterior synechia index was around 20%. The anterior segment optical coherence tomography (OCT) angiography image showed that the iris neovascularization was marked around the pupil in the superficial layer ( Figure , A; green shading). 1 Anterior segment OCT angiography using a swept-source OCT system enabled the visualization of physiological radial vessels in the stroma, even in a brown eye ( Figure , A; red shading). Panretinal photocoagulation was administered immediately and completed in 3 separate installments over 1 month ...
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  Mentions: Kyoto University Graduate School of Medicine Tadamichi Akagi
6. Anterior Segment Optical Coherence Tomography Angiography Imaging of Conjunctiva and Intrasclera in Treated Primary Open-Angle Glaucoma
  
  Explore American Journal of Ophthalmology May 15 2019 Ophthalmology
  
  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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  Mentions: Akitaka Tsujikawa Kyoto University Graduate School of Medicine Tadamichi Akagi
7. A novel strategy for quantification of panoramic en face optical coherence tomography angiography scan field
  
  Explore Home - Springer Apr 18 2019 Ophthalmology
  
  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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  Mentions: Akitaka Tsujikawa Kyoto University Graduate School of Medicine Tadamichi Akagi
8. Visualization of the Lamina Cribrosa Microvasculature in Normal and Glaucomatous Eyes: A Swept-source Optical Coherence Tomography Angiography Study
  
  Explore LWW Online Sep 4 2018 Ophthalmology
  
  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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  Mentions: Akitaka Tsujikawa Kyoto University Graduate School of Medicine Tadamichi Akagi
9. Conjunctival and Intrascleral Vasculatures Assessed Using Anterior-Segment Optical Coherence Tomography Angiography in Normal Eyes
  
  Explore American Journal of Ophthalmology Aug 9 2018 Ophthalmology
  
  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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  Mentions: UCSD Robert N. Weinreb Akitaka Tsujikawa
10. Optic disc microvasculature dropout in primary open-angle glaucoma measured with optical coherence tomography angiography
  
  Explore Journals | PLOS Aug 7 2018 Ophthalmology
  
  Purpose To evaluate microvasculature dropout in the optic disc (Mvd-D) using optical coherence tomography angiography (OCTA) and investigate factors associated with Mvd-D in primary open-angle glaucoma (POAG) eyes. Methods One hundred twenty-three eyes of 123 POAG patients were included from the Diagnostic Innovations in Glaucoma Study. The 3.0×3.0-mm optic nerve head OCTA scans were acquired using a spectral-domain OCT instrument. Images with whole-signal-mode were evaluated. Eyes were classified into 3 categories (Mvd-D, pseudo-Mvd-D, and no Mvd-D). Mvd-D and pseudo-Mvd-D had complete loss of OCTA signals on the temporal side of the optic disc on the en face ...
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  Mentions: National Institutes of Health Optovue Topcon Medical Systems
11. Lacrimal Canaliculus Imaging Using Optical Coherence Tomography Dacryography
  
  Explore Nature Publishing Group Jul 4 2018
  
  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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  Mentions: Nagahisa Yoshimura Tadamichi Akagi
12. Pilot study assessing the structural changes in posttrabecular aqueous humor outflow pathway after trabecular meshwork surgery using swept-source optical coherence tomography
  
  Explore Journals | PLOS Jul 4 2018
  
  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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  Mentions: Akitaka Tsujikawa Kyoto University Graduate School of Medicine Tadamichi Akagi
13. Deep-Layer Microvasculature Dropout by Optical Coherence Tomography Angiography and Microstructure of Parapapillary Atrophy
  
  Explore IOVS Journal Apr 26 2018 Ophthalmology
  
  Purpose : To investigate the association between the microstructure of β-zone parapapillary atrophy (βPPA) and parapapillary deep-layer microvasculature dropout assessed by optical coherence tomography angiography (OCT-A). Methods : Thirty-seven eyes with βPPA devoid of the Bruch's membrane (BM) (γPPA) ranging between completely absent and discontinuous BM were matched by severity of the visual field (VF) damage with 37 eyes with fully intact BM (βPPA +BM ) based on the spectral-domain (SD) OCT imaging. Parapapillary deep-layer microvasculature dropout was defined as a dropout of the microvasculature within choroid or scleral flange in the βPPA on the OCT-A. The widths of βPPA, γPPA, and ...
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  Mentions: UCSD Robert N. Weinreb Linda M. Zangwill
14. Optical Coherence Tomography Angiography Macular Vascular Density Measurements and the Central 10-2 Visual Field in Glaucoma
  
  Explore LWW Online Apr 26 2018 Ophthalmology
  
  Purpose: To evaluate the association between macula vascular density assessed by optical coherence tomography angiography (OCT-A) and central visual field (VF) threshold sensitivities in healthy, glaucoma suspect and glaucoma patients. Methods: A total of 185 eyes from 38 healthy participants, 31 glaucoma suspects, 72 mild glaucoma patients, and 44 moderate/severe glaucoma patients from the Diagnostic Innovations in Glaucoma Study who underwent OCT-A images of the macula and 10-2 VF testing were enrolled in this observational cross-sectional study. The relationship between central VF mean sensitivity and superficial macula whole-image vessel density (wiVD), and the relationship between the MS of the ...
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  Mentions: UCSD Robert N. Weinreb Linda M. Zangwill
15. The Association Between Macula and ONH Optical Coherence Tomography Angiography (OCT-A) Vessel Densities in Glaucoma, Glaucoma Suspect, and Healthy Eyes
  
  Explore LWW Online Mar 1 2018 Ophthalmology
  
  Purpose: To evaluate strength of associations between optical coherence tomography (OCT)-angiography vessel density (VD) measurements in the macula and peripapillary region of the optic nerve head (ONH) with standard structural OCT thickness measures. Materials and Methods: This cross-sectional study included 333 eyes of 219 primary open-angle glaucoma patients, 41 glaucoma suspects, and 73 healthy participants from the Diagnostic Innovations in Glaucoma Study (DIGS) with good quality OCT angiography images. The strength of associations between microvasculature measures in the ONH retinal nerve fiber layer (RNFL) and superficial macula layer was assessed using linear regression models. Associations between ONH and macula ...
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  Mentions: UCSD Robert N. Weinreb Felipe A. Medeiros
16. The Association between Macula and ONH Optical Coherence Tomography Angiography (OCT-A) Vessel Densities in Glaucoma, Glaucoma Suspect and Healthy Eyes
  
  Explore LWW Online Jan 9 2018 Ophthalmology
  
  Purpose: To evaluate strength of associations between Optical Coherence Tomography-Angiography (OCT-A) vessel density (VD) measurements in the macula and peripapillary region of the optic nerve head (ONH) with standard structural OCT thickness measures. Methods: This cross-sectional study included 333 eyes of 219 primary open angle glaucoma patients, 41 glaucoma suspects, and 73 healthy participants from the Diagnostics Innovations in Glaucoma Study (DIGS) with good quality OCT-A images. The strength of associations between microvasculature measures in the ONH retinal nerve fiber layer (RNFL) and superficial macula layer was assessed using linear regression models. Associations between ONH and macula VD, and circumpapillary ...
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  Mentions: UCSD Robert N. Weinreb Felipe A. Medeiros
17. Morphological changes after trabeculectomy in highly myopic eyes with high intraocular pressure by using swept-source optical coherence tomography
  
  Explore ScienceDirect Jul 5 2016 Ophthalmology
  
  Purpose To investigate the effects of intraocular pressure (IOP) reduction on the eyeball shape in highly myopic eyes with high IOP. Methods This study included patients with an axial length ≥26.5 mm and high IOP ≥22 mmHg after receiving maximum medication, with successful trabeculectomy by a single surgeon, and who underwent swept-source optical coherence tomography (SS-OCT) examinations on preoperative and postoperative ≥3 months periods. Eight eyes of 7 patients were included in the analysis. The morphological changes in the eyeball that occurred pre- and post-operation were analyzed from the SS-OCT images. Results In 6 out of 8 examined eyes ...
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  Mentions: Nagahisa Yoshimura Kyoto University Graduate School of Medicine Tadamichi Akagi
18. Microvascular Density in Glaucomatous Eyes with Hemifield Visual Field Defects: An Optical Coherence Tomography Angiography Study
  
  Explore American Journal of Ophthalmology Jun 10 2016 Ophthalmology
  
  Purpose To investigate microcirculation of peripapillary retina and optic disc in eyes with primary open-angle glaucoma (POAG) and hemifield visual field (VF) defects. Design Prospective observational case series with normal comparison group. Methods Sixty eyes with POAG (41 with superior and 19 with inferior hemifield VF defects) and 21 normal eyes were included in this study. Optical coherence tomography (OCT) angiography was used to acquire 3 × 3 mm optic disc cubes, and circumpapillary retinal nerve fiber layer thickness was also measured using OCT. Vessel densities in the peripapillary superficial retina and whole-signal mode optic disc were individually analyzed based on ...
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  Mentions: Nagahisa Yoshimura Kyoto University Graduate School of Medicine Tadamichi Akagi
19. Glaucoma Tube Changes After Suture Lysis Assessed by High-Resolution Anterior Segment Optical Coherence Tomography
  
  Explore JAMA Network Feb 13 2016 Ophthalmology
  
  This Ophthalmic Image shows swept-source optical coherence tomography of glaucoma tube changes after Baerveldt glaucoma implant into the ciliary sulcus. A woman developed Takayasu disease and neovascular glaucoma in her early 20s. She underwent cardiovascular bypass surgery, but lost vision in her left eye. When another cardiovascular bypass was planned in her mid-40s, 95% of her right eye angle was closed, but her intraocular pressure (IOP) did not exceed the high teens while receiving glaucoma medications, probably because of reduced ocular circulation. 1 In preparation for the IOP increase with circulation improvement, we performed a Baerveldt glaucoma implant into the ...
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  Mentions: Nagahisa Yoshimura Kyoto University Graduate School of Medicine Tadamichi Akagi
20. Transient Ciliochoroidal Detachment After Ab Interno Trabeculotomy for Open-Angle Glaucoma A Prospective Anterior-Segment Optical Coherence Tomography Study
  
  Explore JAMA Network Jan 30 2016 Ophthalmology
  
  Importance Although trabeculotomy is a glaucoma surgical procedure for modest intraocular pressure (IOP) reduction, some eyes exhibit very low IOP during the early postoperative period. To our knowledge, the reason and its effect have not been investigated. Objectives To investigate ciliochoroidal detachment (CCD) immediately after ab interno trabeculotomy and evaluate its effect on IOP immediately after surgery. Design, Setting, and Participants This prospective, observational, case series was conducted at Kyoto University Hospital, Kyoto, Japan. Patients with open-angle glaucoma who underwent ab interno trabeculotomy using a microsurgical device by a single surgeon between July 1, 2014, and May 31, 2015, were ...
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  Mentions: Nagahisa Yoshimura Kyoto University Graduate School of Medicine Tadamichi Akagi
21. Structural dissociation of optic disc margin components with optic disc tilting: a spectral domain optical coherence tomography study
  
  Explore Home - Springer Nov 20 2015 Ophthalmology
  
  Purpose To investigate the dissociation of the Bruch’s membrane opening (BMO) from the scleral canal opening (SO) of the optic disc. Methods In this prospective, cross-sectional, observational study, 101 eyes from 101 patients or suspected subjects of primary open angle glaucoma were included. Enhanced depth imaging spectral domain optical coherence tomography images along the long axis of the optic disc were used to visualize better the deep structures around the optic disc on both the temporal and nasal sides. The distances between the BMO and SO were measured at the temporal and nasal sides of the optic disc, and ...
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  Mentions: Masanori Hangai Nagahisa Yoshimura Kyoto University Graduate School of Medicine
22. Effect of Axial Length on Macular Ganglion Cell Complex Thickness and on Early Glaucoma Diagnosis by Spectral-Domain Optical Coherence Tomography
  
  Explore LWW Online Nov 10 2015 Ophthalmology
  
  Purpose: To investigate the effects of the axial length (AL)-related ocular magnification on the thickness of the macular ganglion cell complex (mGCC), and the diagnostic accuracy of the built-in normative database of the spectral-domain optical coherence tomographic (SD-OCT) instrument for early glaucoma detection. Methods: This retrospective study included 41 eyes with early primary open-angle glaucoma and 36 normal eyes. The mGCC thickness within a 20-degree circle, equivalent to a 6 mm diameter in the Gullstrand model eye, was measured in the SD-OCT images. The magnification effect was corrected using Bennett formula, and the mGCC thickness within the actual 6 ...
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  Mentions: Masanori Hangai Nagahisa Yoshimura Kyoto University Graduate School of Medicine
23. OPTICAL COHERENCE TOMOGRAPHIC REFLECTIVITY OF CYSTOID SPACES IS RELATED TO RECURRENT DIABETIC MACULAR EDEMA AFTER TRIAMCINOLONE
  
  Explore LWW Online Aug 10 2014 Ophthalmology
  
  Purpose: To determine the association between reflectivity levels in foveal cystoid spaces on optical coherence tomography images and the course of the logarithm of the minimum angle of resolution (logMAR) after triamcinolone acetonide treatment for diabetic macular edema. Methods: We retrospectively reviewed 58 consecutive eyes treated with an intravitreal or sub-Tenon's injection of triamcinolone acetonide for diabetic macular edema. The foveal cystoid spaces within central 1 mm were circumscribed, followed by measurement of optical coherence tomography reflectivity. The correlation between the reflectivity and visual outcome was investigated. Results: The optical coherence tomography reflectivity levels in foveal cystoid spaces increased ...
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  Mentions: Nagahisa Yoshimura Kyoto University Graduate School of Medicine Tadamichi Akagi
24. Recent advances in OCT imaging of the lamina cribrosa
  
  Explore BJO Online Jun 18 2014 Ophthalmology
  
  The lamina cribrosa (LC) is believed to be the site of injury to retinal ganglion cell axons in glaucoma. The ability to visualise this structure has the potential to help increase our understanding of the disease and be useful in the early detection of glaucoma. While for many years the research on the LC was essentially dependent on histology and modelling, a number of recent advances in optical coherence tomography (OCT) have dramatically improved the ability to visualise the LC, such that it is now possible to image the LC in vivo in humans and animals. In this review, we ...
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  Mentions: University of Pittsburgh University College London Singapore Eye Research Institute
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