1. 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

      Image Evaluation Of Artificial Intelligence Supported Optical Coherence Tomography Angiography Imaging Using OCT-HS100 Device In Diabetic Retinopathy

      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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    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

      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

      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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    3. 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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    4. 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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    5. Anterior Segment Optical Coherence Tomography Angiography of Iris Neovascularization After Intravitreal Ranibizumab and Panretinal Photocoagulation

      Anterior Segment Optical Coherence Tomography Angiography of Iris Neovascularization After Intravitreal Ranibizumab and Panretinal Photocoagulation

      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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    6. 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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    7. 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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    8. 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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    9. 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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    10. Optic disc microvasculature dropout in primary open-angle glaucoma measured with optical coherence tomography angiography

      Optic disc microvasculature dropout in primary open-angle glaucoma measured with optical coherence tomography angiography

      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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    11. 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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    12. 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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    13. Deep-Layer Microvasculature Dropout by Optical Coherence Tomography Angiography and Microstructure of Parapapillary Atrophy

      Deep-Layer Microvasculature Dropout by Optical Coherence Tomography Angiography and Microstructure of Parapapillary Atrophy

      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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    14. Optical Coherence Tomography Angiography Macular Vascular Density Measurements and the Central 10-2 Visual Field in Glaucoma

      Optical Coherence Tomography Angiography Macular Vascular Density Measurements and the Central 10-2 Visual Field in Glaucoma

      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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    15. The Association Between Macula and ONH Optical Coherence Tomography Angiography (OCT-A) Vessel Densities in Glaucoma, Glaucoma Suspect, and Healthy Eyes

      The Association Between Macula and ONH Optical Coherence Tomography Angiography (OCT-A) Vessel Densities in Glaucoma, Glaucoma Suspect, and Healthy Eyes

      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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    16. The Association between Macula and ONH Optical Coherence Tomography Angiography (OCT-A) Vessel Densities in Glaucoma, Glaucoma Suspect and Healthy Eyes

      The Association between Macula and ONH Optical Coherence Tomography Angiography (OCT-A) Vessel Densities in Glaucoma, Glaucoma Suspect and Healthy Eyes

      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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    17. Morphological changes after trabeculectomy in highly myopic eyes with high intraocular pressure by using swept-source optical coherence tomography

      Morphological changes after trabeculectomy in highly myopic eyes with high intraocular pressure by using swept-source optical coherence tomography

      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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    18. Microvascular Density in Glaucomatous Eyes with Hemifield Visual Field Defects: An Optical Coherence Tomography Angiography Study

      Microvascular Density in Glaucomatous Eyes with Hemifield Visual Field Defects: An Optical Coherence Tomography Angiography Study

      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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    19. Glaucoma Tube Changes After Suture Lysis Assessed by High-Resolution Anterior Segment Optical Coherence Tomography

      Glaucoma Tube Changes After Suture Lysis Assessed by High-Resolution Anterior Segment Optical Coherence Tomography

      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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    20. Transient Ciliochoroidal Detachment After Ab Interno Trabeculotomy for Open-Angle Glaucoma A Prospective Anterior-Segment Optical Coherence Tomography Study

      Transient Ciliochoroidal Detachment After Ab Interno Trabeculotomy for Open-Angle Glaucoma A Prospective Anterior-Segment Optical Coherence Tomography Study

      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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    21. Structural dissociation of optic disc margin components with optic disc tilting: a spectral domain optical coherence tomography study

      Structural dissociation of optic disc margin components with optic disc tilting: a spectral domain optical coherence tomography study

      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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    22. Effect of Axial Length on Macular Ganglion Cell Complex Thickness and on Early Glaucoma Diagnosis by Spectral-Domain Optical Coherence Tomography

      Effect of Axial Length on Macular Ganglion Cell Complex Thickness and on Early Glaucoma Diagnosis by Spectral-Domain Optical Coherence Tomography

      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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    23. OPTICAL COHERENCE TOMOGRAPHIC REFLECTIVITY OF CYSTOID SPACES IS RELATED TO RECURRENT DIABETIC MACULAR EDEMA AFTER TRIAMCINOLONE

      OPTICAL COHERENCE TOMOGRAPHIC REFLECTIVITY OF CYSTOID SPACES IS RELATED TO RECURRENT DIABETIC MACULAR EDEMA AFTER TRIAMCINOLONE

      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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    24. Recent advances in OCT imaging of the lamina cribrosa

      Recent advances in OCT imaging of the lamina cribrosa

      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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    1-24 of 38 1 2 »
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    1. (37 articles) Tadamichi Akagi
    2. (34 articles) Kyoto University Graduate School of Medicine
    3. (21 articles) Nagahisa Yoshimura
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    5. (9 articles) Akitaka Tsujikawa
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