All Articles from Tadamichi Akagi -Optical Coherence Tomography News

Articles from Tadamichi Akagi

1-24 of 33 1 2 »
1. 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
2. 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
3. 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
4. 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
5. 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
6. 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
7. 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
8. 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
9. 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
10. 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
11. 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
12. 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
13. 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
14. 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
15. 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
16. 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
17. 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
18. 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
19. 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
20. Alterations in the Neural and Connective Tissue Components of Glaucomatous Cupping after Glaucoma Surgery using Swept Source Optical Coherence Tomography
  
  Explore iovs.org Jan 11 2014 Ophthalmology
  
  Purpose: To visualize changes in deep optic nerve head (ONH) structures following glaucoma surgery using (3-dimensional (3D)) swept-source optical coherence tomography (SS-OCT) and to determine the clinical and structural factors associated with postoperative lamina cribrosa (LC) and prelaminar neural tissue (PLT) changes. Methods: In this prospective observational case series, SS-OCT thin-sliced datasets of the ONH covering a 3×3-mm area comprised of 256 B-scans (interval between scans = ∼12µm) were obtained before and 3 months after the surgery and evaluated in 73 eyes of 73 patients with glaucoma. Bruch's membrane opening (BMO) and anterior LC boundary were manually delineated ...
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  Mentions: Masanori Hangai Nagahisa Yoshimura Kyoto University Graduate School of Medicine
21. Three-Dimensional Imaging of Lamina Cribrosa Defects in Glaucoma Using Swept-Source Optical Coherence Tomography
  
  Explore iovs.org Jul 18 2013 Ophthalmology
  
  Purpose. To visualize lamina cribrosa defects using three-dimensional (3D) swept-source optical coherence tomography (SS-OCT), and to determine the factors associated with this feature. Methods. All subjects were examined using an SS-OCT prototype system, which uses a tunable laser as a light source, operated at 100,000 Hz A-scan repetition rate in the 1050-nm wavelength. A 3D raster scan protocol consisting of 256 × 256 A-scans was acquired over a square area of 3 mm × 3 mm centered on the optic disc. En face sectioned volume and serial en face images and orthogonal (horizontal and vertical) serial B-scans were evaluated. Results. A ...
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  Mentions: Topcon Medical Systems Masanori Hangai Nagahisa Yoshimura
22. Three Dimensional Imaging of the Lamina Cribrosa Defects in Glaucoma Using Swept-source Optical Coherence Tomography
  
  Explore iovs.org Jun 20 2013 Ophthalmology
  
  Purpose: To visualize and analyze focal lamina cribrosa defects using 3-dimensional (3D) swept-source optical coherence tomography (SS-OCT). Methods: All the subjects were examined using an SS-OCT prototype system, which employs a tunable laser as a light source operated at 100,000 Hz A-scan repetition rate in the 1,050 nm wavelength. Three-dimensional raster scan protocol comprising 256 × 256 A-scans was acquired over a square area of 3 mm × 3 mm centered at the optic disc. En face sectioned volume and serial en face images, which were reconstructed from the 3D data set, and orthogonal (horizontal and vertical) serial B-scan were ...
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  Mentions: Masanori Hangai Nagahisa Yoshimura Kyoto University Graduate School of Medicine
23. Macular Imaging in Highly Myopic Eyes With and Without Glaucoma
  
  Explore American Journal of Ophthalmology Jun 20 2013
  
  Purpose To determine how evaluations of macular structures on spectral-domain optical coherence tomography compare with those of the optic disc and circumpapillary retinal nerve fiber layer (RNFL) in discriminating between highly myopic eyes with and without glaucoma. Design Retrospective, comparative study. Methods The appearances of ganglion cell layer and RNFL on Spectralis macular scans (Heidelberg Engineering) and optic disc on photographs were evaluated by 2 observers. The receiver operating characteristic regression was conducted for macular ganglion cell complex and circumpapillary RNFL measurements on RTVue-100 (Optovue). Results Ninety highly myopic eyes (−6.0 to −15.0 diopters; mean deviation [MD], −5 ...
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  Mentions: Optovue Heidelberg Engineering Masanori Hangai
24. Peripapillary Scleral Deformation and Retinal Nerve Fiber Damage in High Myopia Assessed With Swept-Source Optical Coherence Tomography
  
  Explore American Journal of Ophthalmology Feb 26 2013 Ophthalmology
  
  Purpose To study peripapillary morphologic changes in highly myopic eyes using swept-source optical coherence tomography at a longer wavelength. Design Prospective cross-sectional study. Methods Peripapillary regions of 196 eyes of 107 patients with high myopia (refractive error, <−8.0 diopters or axial length, >26.0 mm) were analyzed quantitatively and qualitatively with an swept-source optical coherence tomography prototype system that uses a tunable laser light source operated at a 100,000-Hz A-scan repetition rate in the 1-μm wavelength region. The visual field was evaluated by standard automated perimetry. Area of peripapillary atrophy β and presence of scleral protrusion temporal to ...
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  Mentions: Masanori Hangai Atsushi Nonaka Masahiro Akiba
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