Takao Hirano

Dr. Takao Hirano

Department of Ophthalmology, School of Medicine, Shinshu University, Matsumoto 390-8621, Japan
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Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 December 2018 in BMC Ophthalmology
Verified
Journal Article
Open access
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THTakao Hirano
Takao Hirano
AIAkira Imai
Akira Imai
HKHirotsugu Kasamatsu
Hirotsugu Kasamatsu
SKShinji Kakihara
Shinji Kakihara
YTYuichi Toriyama
Yuichi Toriyama
TMToshinori Murata
Toshinori Murata
The ability to image wide fundus fields and to conduct swift, non-invasive examinations is increasingly important with the escalation in patients with diabetic retinopathy (DR). Fifty eyes of 28 consecutive patients with DR were examined in this prospective observational study. A total of 46 eyes, 25 right and 21 left eyes, of 27 patients (male, 19; female, 8) were ultimately included in the analysis. All patients underwent comprehensive ophthalmological examination. A single image each was obtained using two ultra-wide-field (UWF) imaging systems: Optos® (Optos Carfornia®, Optos PLC, Dunfermline, United Kingdom) and Clarus™ (CLARUS 500™, Carl Zeiss Meditec Inc., Californea, USA), without mydriasis. The total retinal area captured and the obscured retinal area were compared between the two systems using nonparametric Wilcoxon matched-pairs signed-rank analysis. Early Treatment of Diabetic Retinopathy Study (ETDRS) and International Clinical DR severity were analyzed by κ statistics. The Optos® allowed capture of larger areas of the fundus than the Clarus™ (465 ± 117 vs. 243 ± 39 disc areas, P < 0.0001). In 85% (39/46) of Optos® images and 7% (3/46) of Clarus™ images, a slightly obscured area was observed within the ETDRS-7 field area. κ values for ETDRS DR severity and International Clinical DR severity between the Optos® and Clarus™ images were 0.88 and 0.79, respectively. Severity was higher according to Clarus™ images in two eyes in which the ETDRS DR severity grading differed between the systems. Severity was higher in four Clarus™ images and in a single Optos® image in five eyes in which the International Clinical DR severity grading differed between the systems. The Optos® and Clarus™ UWF retinal imaging systems were useful for examining eyes with DR, using single images obtained without mydriasis. The systems were both generally consistent in assessing DR severity, with some partial discrepancies. It is important to understand the characteristics of each respective UWF retinal imaging system when using them to assess DR.

1 June 2020 in Ophthalmology Retina
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Journal Article
Open access
THTakao Hirano
Takao Hirano
KHKen Hoshiyama
Ken Hoshiyama
KHKazutaka Hirabayashi
Kazutaka Hirabayashi
MWMasumi Wakabayashi
Masumi Wakabayashi
YTYuichi Toriyama
Yuichi Toriyama
TMToshinori Murata
Toshinori Murata
To compare neovascularization identified in proliferative diabetic retinopathy (PDR) eyes by widefield swept-source (SS) OCT angiography (OCTA) using vitreoretinal interface (VRI) slab images, composed by automated and manual segmentation, with that identified by fluorescein angiography (FA). Retrospective study. Forty-two eyes of 30 treatment-naïve PDR patients who visited the outpatient clinic of the Department of Ophthalmology, Shinshu University, from June 2018 through October 2019. All patients underwent comprehensive ophthalmologic examinations, including SS-OCTA and FA. Neovascularization detected by en face SS-OCTA 15 × 15-mm VRI slab images and by FA in the same 15 × 15-mm areas were compared in terms of number and structure. Among 100 neovascularizations detected by FA, 73 also were visualized as neovascularization in SS-OCTA VRI slab images using automated segmentation. The sensitivity of VRI slab images for detecting neovascularization was 73%. Among the remaining 27 neovascularizations detected only by FA, but not by VRI slab, 15 were intraretinal microvascular abnormalities with fluorescence leakage, 1 was a diabetic papillopathy, and 11 were flat neovascularizations on the internal limiting membrane surface that were missed because of segmentation error. Conversely, among the 98 neovascularizations detected on VRI slab images, 25 were not detected as neovascularizations by FA. They included 9 small neovascularizations that exhibited too little leakage on FA and 16 false-positive results that were the result of segmentation errors. After reconstruction of SS-OCTA VRI slab images by means of manual segmentation, the sensitivity of VRI slab images for detecting neovascularizations increased to 84%. The efficacy of SS-OCTA VRI slab images for detecting neovascularizations in PDR was comparable with that of FA. Swept-source OCTA VRI slab images may be better than FA for identifying intraretinal microvascular abnormalities and diabetic papillopathy from neovascularizations. Notably, however, FA and SS-OCTA VRI slab images demonstrated differences in identification efficacy in cases of small and flat neovascularizations. Further exploration of SS-OCTA technology is warranted to address this issue.

18 December 2014 in Ophthalmic Research
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Journal Article
Closed access
WKWataru Kikushima
Wataru Kikushima
AIAkira Imai
Akira Imai
YTYuichi Toriyama
Yuichi Toriyama
THTakao Hirano
Takao Hirano
TMToshinori Murata
Toshinori Murata
TITatsuro Ishibashi
Tatsuro Ishibashi
Background/Aims: To investigate the dynamics of macular hole (MH) closure in gas-filled eyes starting 20 min after vitrectomy using swept source optical coherence tomography (SS-OCT). Methods: Twenty consecutive eyes with MH underwent vitrectomy with internal limiting membrane peeling and gas tamponade. SS-OCT imaging was performed approximately 20 min after the operation, and then once a day, until MH closure was confirmed. The correlation between the base, top and minimum hole diameters and the duration required for MH closure was investigated. Results: MH closure in gas-filled eyes was confirmed in 1 eye on day 0, 10 eyes on day 1, 2 eyes on day 2, and 3 eyes on day 3, at which times face-down posturing was discontinued without MH recurrence. SS-OCT revealed a distinct closure pattern within the first 24 h postoperatively. MHs closing by day 1 had a significantly smaller minimum diameter (312.5 ± 105.2 µm) than holes closing on day 2 or later (510.8 ± 153.5 µm; p = 0.019). Conclusions: SS-OCT enables tomographic images of MH in gas-filled eyes immediately postoperatively, thus permitting early discontinuation of, or no necessity for, face-down positioning upon confirmation of MH closure.

24 February 2021 in Scientific Reports
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Journal Article
Open access
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THTakao Hirano
Takao Hirano
YTYuichi Toriyama
Yuichi Toriyama
YTYoshihiro Takamura
Yoshihiro Takamura
MSMasahiko Sugimoto
Masahiko Sugimoto
TNTaiji Nagaoka
Taiji Nagaoka
TMToshinori Murata
Toshinori Murata
This prospective, open-label, single-arm, non-randomized clinical trial, assessed the efficacy of a 2-year treat-and-extend (T&E) regimen involving intravitreal aflibercept injection (IAI), with the longest treatment interval set to 16 weeks, and adjunct focal/grid laser in diabetic macula edema (DME) patients. We examined 40 eyes (40 adults) with fovea-involving DME from 8 Japanese centers between April 2015 and February 2017. Participants received IAI with an induction period featuring monthly injections and a subsequent T&E period featuring 8–16-week injection interval, adjusted based on optical coherence tomography findings. The primary endpoints were mean changes in the best-corrected visual acuity (BCVA) and central subfield macular thickness (CST) from baseline. Thirty patients (75%) completed the 2-year follow-up. The mean BCVA and CST changed from 60.5 ± 15.6 letters and 499.2 ± 105.6 µm at baseline to 66.6 ± 17.1 letters (P = 0.217) and 315.2 ± 79.0 µm (P < 0.001), respectively, after 2 years. The treatment interval was extended to 12 and 16 weeks in 6.7% and 66.7% of patients, respectively, at the end of 2 years. The T&E aflibercept regimen with the longest treatment interval set to 16 weeks, with adjunct focal/grid laser may be a rational 2-year treatment strategy for DME.

28 October 2022 in Graefe's Archive for Clinical and Experimental Ophthalmology
Verified
Journal Article
Closed access
PDF file
THTakao Hirano
Takao Hirano
KHKen Hoshiyama
Ken Hoshiyama
YTYoshiaki Takahashi
Yoshiaki Takahashi
TMToshinori Murata
Toshinori Murata

5 July 2023 in Scientific Reports
Verified
Journal Article
Open access
PDF file
THTakao Hirano
Takao Hirano
AKAkane Kumazaki
Akane Kumazaki
RTRyuji Tomihara
Ryuji Tomihara
SISyun Ito
Syun Ito
KHKen Hoshiyama
Ken Hoshiyama
TMToshinori Murata
Toshinori Murata
Our retrospective, single-center, observational study aimed to evaluate the initial responses to intravitreal injection of brolucizumab (IVBr) in patients undergoing anti-vascular endothelial growth factor (VEGF) therapy for diabetic macular edema (DME). In total, 23 eyes of 20 patients with DME treated with at least one intravitreal injection of ranibizumab or aflibercept within one year and then switched to IVBr were included. Best corrected visual acuity (BCVA), central macular thickness (CMT), and macular volume (MV) on optical coherence tomography images were evaluated just before the most recent conventional anti-VEGF (ranibizumab/aflibercept) injection therapy (V1), one month after the most recent traditional anti-VEGF therapy (V2), just before the first IVBr (V3), and one month after the first IVBr (V4). BCVA, CMT, MV, and presence of intraocular inflammation (IOI) were evaluated at each visit. Anterior chamber flare values were also examined at V3 and V4. BCVA showed significant improvement at V2 (0.30 ± 0.23) than V1 (0.39 ± 0.29) and at V4 (0.34 ± 0.26) than V3 (0.48 ± 0.34) (P = 0.002, P < 0.001). However, no significant difference was observed between V2 and V4 (P = 0.257). CMT was significantly thinner at V2 (346.8 ± 90.2 µm) than V1 (495.5 ± 123.8 µm), and at V4 (322.2 ± 95.7 µm) than V3 (536.5 ± 166.0 µm) (P < 0.001, P < 0.001), but no significant difference was observed between V2 and V4 (P = 0.140). MV was significantly smaller at V2 (11.6 ± 2.0 mm3) than V1 (12.6 ± 1.9 mm3) and at V4 (11.2 ± 2.0 mm3) than V3 (12.6 ± 2.0 mm3) (P < 0.001, P < 0.001), and even significantly smaller at V4 than V2 (P = 0.009). No patient had IOI. No significant changes were observed in anterior chamber flare values between V3 and V4 (25.6 ± 14.6 vs. 24.0 ± 11.5 photon count/ms; P = 0.543). Both CMT and MV significantly reduced without any adverse events one month after switching from conventional anti-VEGF to IVBr therapy for DME, including IOI. MV was significantly lower for IVBr than anti-VEGF therapy after one month of treatment. Therefore, brolucizumab may be a viable treatment option for DME patients considering switching from conventional anti-VEGF agents for various reasons, such as poor response or inability to extend dosing intervals.