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Dive into the research topics where Genichiro Takahashi is active.

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Featured researches published by Genichiro Takahashi.


Clinical Ophthalmology | 2012

Cytomegalovirus retinitis treated with valganciclovir in Wegener’s granulomatosis

Yoshiaki Kabata; Genichiro Takahashi; Hiroshi Tsuneoka

A case of cytomegalovirus (CMV) retinitis in a patient with Wegener’s granulomatosis treated with oral valganciclovir as maintenance therapy is reported. A 68-year-old male patient with anti-proteinase-3 ANCA-positive Wegener’s granulomatosis who was receiving immunosuppressive therapy with methylprednisolone, cyclophosphamide, and azathioprine developed CMV retinitis. The patient received intravenous ganciclovir as induction therapy and oral valganciclovir as maintenance therapy. The patient responded to treatment and showed no recurrence for 8 months. There were no serious adverse effects associated with oral valganciclovir. Oral valganciclovir is convenient and effective for the management of CMV retinitis in the patient with Wegener’s granulomatosis.


Graefes Archive for Clinical and Experimental Ophthalmology | 2015

Measurement of early changes in anterior chamber morphology after cataract extraction measured by anterior segment optical coherence tomography.

Kozue Kasai; Genichiro Takahashi; Koichi Kumegawa; Murat Dogru

ObjectiveTo evaluate the serial changes in anterior chamber depth (ACD) and angle parameters early after cataract surgery using anterior segment optical coherence tomography (ASOCT).MethodsThis was a retrospective chart review, case–control study; 150 eyes of 106 patients who underwent cataract surgery. Based on ACD and angle findings, the eyes were classified into two groups, open-angle eyes (87 eyes) and narrow-angle eyes (63 eyes). ASOCT was used to measure ACD and angle parameters (angle opening distance, angle recess area, trabecular iris space area, and trabecular iris angle (TIA [1]). Serial changes in each group were measured before and 1 day, 1 week, and 1 month after cataract surgery, and the differences between the two groups were compared.ResultsACD and all angle parameters in both groups at each examination time after cataract surgery were significantly different from the preoperative values (p < 0.01). In addition, all angle parameters significantly differed between the two groups at each examination time after cataract surgery (p < 0.001). However, ACD after surgery was not significantly different, irrespective of ACD before surgery. ACD and TIA500 both showed significantly greater changes from before surgery to 1 day after surgery in narrow-angle eyes compared to open-angle eyes (p < 0.001).ConclusionsCataract surgery increases ACD and all angle parameters early after the surgery. However, the degree of angle widening in narrow-angle eyes was not as much as that in open-angle eyes, suggesting that factors other than the lens influence the angle closure.


Clinical Ophthalmology | 2015

Indications and postoperative treatment for Ex-PRESS(®) insertion in Japanese patients with glaucoma: comparison with standard trabeculectomy.

Noriko Kato; Genichiro Takahashi; Koichi Kumegawa; Yoshiaki Kabata; Hiroshi Tsuneoka

Background We investigated indications and early postoperative treatment for Ex-PRESS® insertion for glaucoma by comparing postoperative outcomes with those for standard trabeculectomy. Methods Ex-PRESS insertion was performed in 21 eyes and standard trabeculectomy (TLE) in 22 eyes. Mean intraocular pressure (IOP) in the 6 months after surgery, success rate for postoperative IOP decline, postoperative complications, postoperative treatment, filtering blebs, and indications were then retrospectively investigated. Results Mean postoperative IOP did not differ significantly between the groups at any observation time for 6 months after surgery. Further, it did not differ between either the groups of patients with primary open-angle glaucoma (POAG) and neovascular glaucoma (NTG), or the patients with primary open-angle glaucoma and NTG in the Ex-PRESS group. Comparison of success rates in reduction of postoperative IOP between the groups under the following four survival conditions showed no significant differences: postoperative IOP <30% of the preoperative IOP, complete success (no additional ophthalmic solution), and qualified success (ophthalmic solution required); 5 mmHg ≤ postoperative IOP ≤21 mmHg, complete success (no additional ophthalmic solution), and qualified success (ophthalmic solution required). With regard to postoperative complications and postoperative treatment, the incidence of hyphema was significantly lower in the Ex-PRESS group, but no other significant intergroup differences were seen. The height of the filtering bleb was lower in the Ex-PRESS group. Conclusion Postoperative outcomes in the Ex-PRESS and TLE groups were comparable. The incidence of hyphema was significantly lower in the Ex-PRESS group. Ex-PRESS insertion appears to be useful in patients with NTG and in those prone to postoperative bleeding. There were no significant intergroup differences in postoperative treatment. Assessment of outcome after Ex-PRESS insertion was difficult in some patients. Postoperative treatment should be developed to suit the specific requirements of Ex-PRESS insertion.


Japanese Journal of Ophthalmology | 1999

Short-Term Fluctuation of Blue-on-Yellow Perimetry in Normal Eyes

Genichiro Takahashi; Yoko Aoki; Kenji Kitahara

PURPOSE To evaluate short term fluctuation (SF) of blue-on-yellow perimetry (B/Y) as compared with white-on-white perimetry (W/W) in normal eyes. SUBJECTS AND METHOD One eye each of 25 healthy persons underwent B/Y and W/W perimetry repeated 5 times each. The test subjects had no previous experience of perimetry. An automated perimeter, Humphrey Field Analyzer, model 750, was used throughout. RESULTS The SF at the first session of B/Y perimetry averaged 2.02 dB. This value was significantly different from those of the subsequent 4 sessions. Each of SF of B/Y perimetry at the first two sessions was significantly different from that of W/W perimetry at the first two sessions. The SF of B/Y perimetry showed wider fluctuations than those of W/W perimetry at each session. CONCLUSION B/Y perimetry in normal eyes showed individual differences as well as fluctuations between the initial and consecutive sessions. This feature has to be considered in interpretation of the findings.


Graefes Archive for Clinical and Experimental Ophthalmology | 2017

Predicting conversion to glaucoma using standard automated perimetry and frequency doubling technology

Genichiro Takahashi; Shaban Demirel; Chris A. Johnson

PurposeTo test the hypothesis that development of glaucomatous visual fields can be predicted several years earlier from prior visual field information.MethodsOne-hundred and seven eyes with glaucomatous optic neuropathy (n = 47 eyes) or which were suspicious for glaucoma (n = 60) were prospectively enrolled in a longitudinal study. Visual fields were evaluated on an annual basis using standard automated perimetry (SAP), the original version of frequency doubling technology (FDT) perimetry, and a custom version of FDT that used the 24-2 stimulus pattern. All SAP fields were within normal limits at the initial visit. When the SAP glaucoma hemifield test was ‘outside normal limits’ or the pattern standard deviation probability was worse than the lower 5th percentile or more than two clustered locations at the p < 0.05 level were present on the pattern deviation probability plot, an eye was defined as being abnormal. We used a classification tree analysis to predict which eyes would convert, using only baseline test results.ResultsClassification trees that were constructed using only baseline data had excellent specificity (near 100%) but worse sensitivity (25–50%) for predicting which eyes would convert during follow-up.ConclusionsPredictive information is present in visual field results, even when they are still within normal limits.


Clinical Ophthalmology | 2017

Irrigation dynamic pressure-assisted hydrodissection during cataract surgery

Yoichiro Masuda; Hisaharu Iwaki; Noriko Kato; Genichiro Takahashi; Kotaro Oki; Hiroshi Tsuneoka

The irrigation dynamic pressure-assisted hydrodissection technique (irrigation-hydro [iH]) does not require performing manual hydrodissection using a syringe and cannula to achieve cortical-capsular cleavage during cataract surgery. Since the iH technique uses the phaco tip to intentionally vacuum the intraocular fluid in order to induce the irrigation dynamic pressure for cortical-capsular cleavage, there is a reduction in the intraocular pressure (IOP) from the bottle-height-dependent hydrostatic pressure. Thus, since the peak irrigation pressure derived from the phaco tip sleeve will be limited by the height of the irrigation fluid bottle, this is advantageous in helping to avoid excessively high IOP during cortical-capsular hydrodissection. Using this technique, we were able to effectively perform phacoemulsification without complications in 607 of 609 cataract eyes. Our findings show that utilization of the iH technique would be of benefit to patients, as it prevents high-pressure hydrodissection-related complications, such as capsular block syndrome and tears in the anterior hyaloid membrane during cataract surgery.


Clinical Ophthalmology | 2013

Neodymium:yttrium-aluminum garnet capsulotomy rates after combined cataract surgery with implantation of a 4% water content hydrophobic acrylic intraocular lens and vitrectomy.

Yoshiaki Kabata; Genichiro Takahashi; Hiroshi Tsuneoka

Background The purpose of this study was to examine neodymium:yttrium-aluminum garnet (Nd:YAG) capsulotomy rates after combined cataract surgery with implantation of a three-piece 4% water content hydrophobic acrylic intraocular lens (X-70, Eternity®) and vitrectomy, and compare diabetic retinopathy with nondiabetic retinopathy. Methods Nd:YAG capsulotomy rates were evaluated for 72 eyes of 72 patients with diabetic retinopathy and 81 eyes of 81 patients with nondiabetic retinopathy (50 eyes with retinal detachment, 13 eyes with macular hole, nine eyes with epiretinal membrane, seven eyes with branch retinal vein occlusion, and two eyes with uveitis) who underwent combined cataract surgery and vitrectomy and implantation of X-70. Results Two years after combination surgery, four of 72 eyes (5.6%) in the diabetic retinopathy group and four of 81 eyes (5.0%) in the nondiabetic retinopathy group required Nd:YAG capsulotomies. Kaplan–Meier survival analysis showed no statistically significant differences between the two groups (P=0.30, Mantel–Cox log-rank test). Conclusion The rate of Nd:YAG capsulotomy did not significantly differ between diabetic retinopathy and nondiabetic retinopathy after combined cataract surgery with implantation of the X-70 and vitrectomy. X-70 is an acceptable intraocular lens for patients undergoing combined cataract surgery and vitrectomy.


Neuro-Ophthalmology | 2001

Objective visual field testing with functional magnetic resonance imaging

Masaki Yoshida; Masahiro Ida; Genichiro Takahashi; Thien Huong Nguyen; M.T. Iba-Zizen; J.L. Stievenart; Shinsuke Kikuchi; Takaaki Hara; Kenji Kitahara; Emmanuel Alain Cabanis

Purpose : To detect cortical retinotopy using the functional magnetic resonance imaging technique at clinical circumstances. Methods : Four normal volunteers were examined. Four experiments were performed on each subject: a ‘central-peripheral’ visual field stimulation and an ‘upper-lower’ visual field stimulation, both for right and left visual hemifields. The checkerboard stimuli, presented on a front projection screen, subtended 3 degrees of visual angle in height and 5 degrees in width. Sequential paradigms alternated rest phases with no checkerboard stimulation and stimulation phases. For the ‘central-peripheral’ visual field stimulation, the checkerboard was presented to either the central or peripheral visual field. During the ‘upper-lower’ visual field stimulation, the checkerboard was presented to either the upper or lower visual field. Results : The central visual field stimulation revealed a broad activated area in the contralateral occipital pole, whereas the peripheral visual field stimulation displayed a more anterior and narrower activated area. The ‘upper-lower’ visual field stimulation revealed broad activated areas covering the contralateral occipital pole. The upper visual field stimulation revealed the center of the cortical activation located inferiorly to lower visual field stimulation. Conclusion : Retinotopical eccentricity in the primary visual cortex is accurately detected using simple visual stimulations partially presented to the central-peripheral visual field. Upper visual field stimulation bordering the horizontal meridian could be differentiated from lower visual field stimulation in the associated visual cortex. This technique may help to evaluate the visual field.


American Journal of Ophthalmology | 2011

Vision-related quality of life in patients undergoing silicone tube intubation for lacrimal passage obstructions.

Yoshiaki Kabata; Satoshi Goto; Genichiro Takahashi; Hiroshi Tsuneoka


Ophthalmology | 2005

The Effect of Periocular Warming on Accommodation

Yoko Takahashi; Michihito Igaki; Atsushi Suzuki; Genichiro Takahashi; Murat Dogru; Kazuo Tsubota

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Kenji Kitahara

Jikei University School of Medicine

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Hiroshi Tsuneoka

Jikei University School of Medicine

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Tadashi Nakano

Jikei University School of Medicine

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Atsushi Suzuki

Fujita Health University

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Yoko Takahashi

Jikei University School of Medicine

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Yoshiaki Kabata

Jikei University School of Medicine

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