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Dive into the research topics where Kazuhiro Matsumura is active.

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Featured researches published by Kazuhiro Matsumura.


American Journal of Ophthalmology | 2012

Visual Performance After Posterior Chamber Phakic Intraocular Lens Implantation and Wavefront-Guided Laser In Situ Keratomileusis for Low to Moderate Myopia

Kazutaka Kamiya; Akihito Igarashi; Kimiya Shimizu; Kazuhiro Matsumura; Mari Komatsu

PURPOSE To compare postoperative visual function after implantable collamer lens (ICL) implantation and after wavefront-guided laser in situ keratomileusis (LASIK) in eyes with low to moderate myopia. DESIGN Retrospective observational case study. PATIENTS AND METHODS We investigated 30 eyes of 20 patients undergoing ICL implantation and 64 eyes of 38 patients undergoing wavefront-guided LASIK for the correction of low to moderate myopia (manifest spherical equivalent: -3.00 to -5.88 diopters [D]). Ocular higher-order aberrations (HOAs) and contrast sensitivity (CS) function were measured by Hartmann-Shack aberrometry and a contrast sensitivity unit before and 3 months after surgery, respectively. From the contrast sensitivity, the area under the log contrast sensitivity function was calculated. RESULTS For 4-mm and 6-mm pupils, the changes in ocular third-order aberrations, fourth-order aberrations, and total HOAs after ICL implantation were significantly less than those after wavefront-guided LASIK (P < .05, Mann-Whitney U test). The postoperative area under the log contrast sensitivity function was significantly increased after ICL implantation (P < .001), whereas, after wavefront-guided LASIK, it was not significantly changed (P = .11). CONCLUSIONS ICL implantation induces significantly fewer ocular HOAs than wavefront-guided LASIK. Moreover, CS was significantly improved after ICL implantation but unchanged after wavefront-guided LASIK in eyes with low to moderate myopia. Thus, even in the correction of low to moderate myopia, ICL implantation appears to be superior in visual performance to wavefront-guided LASIK, suggesting that it may be a viable surgical option for the treatment of such eyes.


Journal of Cataract and Refractive Surgery | 2014

Long-term quality of life after posterior chamber phakic intraocular lens implantation and after wavefront-guided laser in situ keratomileusis for myopia

Hidenaga Kobashi; Kazutaka Kamiya; Akihito Igarashi; Kazuhiro Matsumura; Mari Komatsu; Kimiya Shimizu

Purpose To compare the vision‐related quality of life 5 years after Implantable Collamer Lens phakic intraocular lens (pIOL) implantation and after wavefront‐guided laser in situ keratomileusis (LASIK) for myopia. Setting Department of Ophthalmology, Kitasato University, Kanagawa, Japan. Design Retrospective case series. Methods Quality of life was measured with the National Eye Institute Refractive Error Quality of Life instrument in consecutive patients 5 years after pIOL implantation or wavefront‐guided LASIK to correct myopia. Results Phakic IOL implantation was performed in 48 patients and LASIK in 55 patients. The scores for activity limitations, symptoms, appearance, and satisfaction with correction were significantly higher in the pIOL group than in the LASIK group (P<.05, Mann‐Whitney U test). No significant differences in other scores were observed between the 2 groups (P≥.05). The scores for near vision and dependence on correction were significantly higher in the younger subgroup than in the older subgroup with both techniques. Conclusions Phakic IOL implantation may offer significant vision‐related quality‐of‐life advantages (eg, fewer activity limitations and symptoms and better appearance and satisfaction with correction) over wavefront‐guided LASIK for myopia in the long term. Moreover, refractive surgery may provide a better quality of life in younger patients. Financial Disclosure Dr. Shimizu is a consultant to Staar Surgical Co. No other author has a financial or proprietary interest in any material or method mentioned.


Scientific Reports | 2016

Comparison of size modulation and conventional standard automated perimetry with the 24-2 test protocol in glaucoma patients

Kazunori Hirasawa; Nobuyuki Shoji; Masayuki Kasahara; Kazuhiro Matsumura; Kimiya Shimizu

This prospective randomized study compared test results of size modulation standard automated perimetry (SM-SAP) performed with the Octopus 600 and conventional SAP (C-SAP) performed with the Humphrey Field Analyzer (HFA) in glaucoma patients. Eighty-eight eyes of 88 glaucoma patients underwent SM-SAP and C-SAP tests with the Octopus 600 24-2 Dynamic and HFA 24-2 SITA-Standard, respectively. Fovea threshold, mean defect, and square loss variance of SM-SAP were significantly correlated with the corresponding C-SAP indices (P < 0.001). The false-positive rate was slightly lower, and false-negative rate slightly higher, with SM-SAP than C-SAP (P = 0.002). Point-wise threshold values obtained with SM-SAP were moderately to strongly correlated with those obtained with C-SAP (P < 0.001). The correlation coefficients of the central zone were significantly lower than those of the middle to peripheral zone (P = 0.031). The size and depth of the visual field (VF) defect were smaller (P = 0.039) and greater (P = 0.043), respectively, on SM-SAP than on C-SAP. Although small differences were observed in VF sensitivity in the central zone, the defect size and depth and the reliability indices between SM-SAP and C-SAP, global indices of the two testing modalities were well correlated.


International Journal of Ophthalmology | 2016

Comparison of corneal biomechanical properties in normal tension glaucoma patients with different visual field progression speed

Ying Hong; Nobuyuki Shoji; Tetsuya Morita; Kazunori Hirasawa; Kazuhiro Matsumura; Masayuki Kasahara; Kimiya Shimizu

AIM To compare the corneal biomechanical properties difference by ocular response analyzer (ORA) in normal tension glaucoma (NTG) patients with different visual field (VF) progression speed. METHODS NTG patients with well-controlled Goldmann applanation tonometer (GAT) who routinely consulted Kitasato University Hospital Glaucoma Department between January 2010 and February 2014 were enrolled. GAT and ORA parameters including corneal compensated intraocular pressure (IOPcc), Goldmann estimated intraocular pressure (IOPg), corneal hysteresis (CH), corneal resistance factor (CRF) were recorded. VF was tested by Swedish interactive threshold algorithm (SITA)-standard 30-2 fields. All patients underwent VF measurement regularly and GAT did not exceed 15 mm Hg at any time during the 3y follow up. Patients were divided into four groups according to VF change over 3y, and ORA findings were compared between the upper 25(th) percentile group (slow progression group) and the lower 25(th) percentile group (rapid progression group). RESULTS Eighty-two eyes of 56 patients were studied. There were 21 eyes (21 patients) each in rapid and slow progression groups respectively. GAT, IOPcc, IOPg, CH, CRF were 12.1±1.4 mm Hg, 15.8±1.8 mm Hg, 12.8±2.0 mm Hg, 8.4±1.1 mm Hg, 7.9±1.3 mm Hg respectively in rapid progression group and 11.5±1.3 mm Hg, 13.5±2.1 mm Hg, 11.2±1.6 mm Hg, 9.3±1.1 mm Hg, 8.2±0.9 mm Hg respectively in slow progression group (P=0.214, <0.001, 0.007, 0.017, 0.413, respectively). In bivariate correlation analysis, IOPcc, IOPcc-GAT and CH were significant correlated with mΔMD (r=-0.292, -0.312, 0.228 respectively, P=0.008, 0.004, 0.039 respectively). CONCLUSION Relatively rapid VF progression occurred in NTG patients whose IOPcc are rather high, CH are rather low and the difference between IOPcc and GAT are relatively large. Higher IOPcc and lower CH are associated with VF progression in NTG patients. This study suggests that GAT measures might underestimate the IOP in such patients.


Medicine | 2015

Interface Fluid Syndrome Induced by Uncontrolled Intraocular Pressure Without Triggering Factors After LASIK in a Glaucoma Patient: A Case Report

Nobuyuki Shoji; Akira Ishida; Takahiro Haruki; Kazuhiro Matsumura; Masayuki Kasahara; Kimiya Shimizu

AbstractThis study sought to describe a glaucoma patient with interface fluid syndrome (IFS) induced by uncontrolled intraocular pressure (IOP) without triggering factors after laser in situ keratomileusis (LASIK).Case report and review of the literature.A 23-year-old man with open-angle glaucoma underwent bilateral LASIK for myopia in 2009. Two years later, the patient reported sudden vision loss. The IOP in the right eye was not measurable using Goldmann applanation tonometry (GAT), but was determined to be 33.7 mm Hg using a noncontact tonometer. IFS was diagnosed based on the presence of space-occupying interface fluid on anterior segment optical coherence tomography images. After a trabeculectomy was performed, the IOP decreased to 10 mm Hg, and GAT measurement became possible. However, the corneal fold remained visible in the flap interface. Six months later, the IOP in the left eye increased, and a trabeculectomy was performed during the early stages of this increase in IOP. Following this procedure, the IOP decreased, and visual acuity remained stable.In glaucoma cases that involve a prior increase in IOP, IOP can continue to increase during the disease course even if temporary control of IOP has been achieved. If LASIK is performed in such cases, the treatment of glaucoma becomes insufficient because of underestimation of the typical IOP. In fact, the measurement of IOP can become difficult because of high-IOP levels. Therefore, LASIK should not be performed on patients with glaucoma who are at high risk of elevated IOP.


Translational Vision Science & Technology | 2017

Diagnostic Ability and Repeatability of a New Supra-Threshold Glaucoma Screening Program in Standard Automated Perimetry

Natsumi Takahashi; Kazunori Hirasawa; Miki Hoshina; Masayuki Kasahara; Kazuhiro Matsumura; Nobuyuki Shoji

Purpose We assess the diagnostic ability and repeatability of a new suprathreshold glaucoma screening test (GST) comprising 28 test points and a 1-of-3 sampling strategy at 95% of the normal limit for standard automated perimetry (SAP) in early to advanced glaucoma. Methods This prospective cross-sectional study included 96 eyes of patients with early, moderate, or advanced glaucoma and 37 eyes of normal controls. Participants were evaluated by the G-Dynamic threshold test once and the GST twice, in random order, using the Octopus 600 perimeter. The diagnostic ability of GST was assessed by comparison with the G-Dynamic threshold obtained by receiver operating characteristic analysis. Repeatability was assessed by κ statistics for agreement on glaucoma diagnosis and each test point. Results Although the G-Dynamic test exhibited significantly higher areas under the curve (AUC) than the GST1st (P = 0.009) in early glaucoma, there were no significant differences in any other AUCs between the two methods. The κ values for repeatability of glaucoma diagnosis and each test point were 0.747 to 1.0 and 0.537 to 1.0, respectively. The duration of the GST in the control and early glaucoma groups was less than a minute, while that in the moderate and advanced glaucoma groups was within 1.5 minutes. Conclusion The diagnostic ability of the new suprathreshold GST for early to advanced glaucoma was high, with moderate to strong repeatability and short test duration. Translational Relevance There currently are no prominent suprathreshold screening strategies using SAP. The GST would be an effective clinical method for glaucoma screening.


Scientific Reports | 2017

Diagnostic capability of Pulsar perimetry in pre-perimetric and early glaucoma

Kazunori Hirasawa; Natsumi Takahashi; Kazuhiro Matsumura; Masayuki Kasahara; Nobuyuki Shoji

This study aimed to compare the diagnostic capability of Pulsar perimetry (Pulsar) in pre-perimetric glaucoma (PPG) and early glaucoma (EG) with that of Flicker perimetry (Flicker) and spectral-domain optical conference tomography (SD-OCT). This prospective cross-sectional study included 25 eyes of 25 PPG patients, 35 eyes of 35 EG patients, and 42 eyes of 42 healthy participants. The diagnostic capability using the area under the curve (AUC) of the best parameter and agreement of detectability between structural and functional measurements were compared. For PPG patients, the AUC of Pulsar, Flicker, OCT-disc, and OCT-macular was 0.733, 0.663, 0.842, and 0.780, respectively. The AUC of Flicker was significantly lower than that of OCT-disc (p = 0.016). For EG patients, the AUC of Pulsar, Flicker, OCT-disc, and OCT-macular were 0.851, 0.869, 0.907, and 0.861, respectively. There was no significant difference in AUC among these methods. The agreement between structural and functional measurements expressed by kappa value ranged from −0.16 to 0.07 for PPG and from 0.01 to 0.25 for EG. Although the diagnostic capability of Pulsar in the PPG and EG groups was equal to that of Flicker and SD-OCT, the agreements between structural and functional measurements for both PPG and EG were poor.


Current Eye Research | 2017

Comparison of Size Modulation Standard Automated Perimetry and Conventional Standard Automated Perimetry with a 10-2 Test Program in Glaucoma Patients

Kazunori Hirasawa; Natsumi Takahashi; Tsukasa Satou; Masayuki Kasahara; Kazuhiro Matsumura; Nobuyuki Shoji

ABSTRACT Purpose: This prospective observational study compared the performance of size modulation standard automated perimetry with the Octopus 600 10-2 test program, with stimulus size modulation during testing, based on stimulus intensity and conventional standard automated perimetry, with that of the Humphrey 10-2 test program in glaucoma patients. Methods: Eighty-seven eyes of 87 glaucoma patients underwent size modulation standard automated perimetry with Dynamic strategy and conventional standard automated perimetry using the SITA standard strategy. The main outcome measures were global indices, point-wise threshold, visual defect size and depth, reliability indices, and test duration; these were compared between size modulation standard automated perimetry and conventional standard automated perimetry. Results: Global indices and point-wise threshold values between size modulation standard automated perimetry and conventional standard automated perimetry were moderately to strongly correlated (p < 0.01). However, the correlation coefficient of point-wise threshold value for the central zone was significantly lower than that for the peripheral zone (χ2 > 33.40, p < 0.01). Better mean defect and point-wise threshold values were obtained with size modulation standard automated perimetry than with conventional standard automated perimetry, but the visual-field defect size was smaller (p < 0.01) and depth shallower (p < 0.01) on size modulation-standard automated perimetry than on conventional standard automated perimetry. The reliability indices, particularly the false-negative response, of size modulation standard automated perimetry were worse than those of conventional standard automated perimetry (p < 0.01). The test duration was 6.5% shorter with size modulation standard automated perimetry than with conventional standard automated perimetry (p = 0.02). Conclusions: Global indices and the point-wise threshold value of the two testing modalities correlated well. However, the potential of a large stimulus presented at an area with a decreased sensitivity with size modulation standard automated perimetry could underestimate the actual threshold in the 10-2 test protocol, as compared with conventional standard automated perimetry.


Japanese Journal of Ophthalmology | 2016

Short-term evaluation of Trabectome surgery performed on Japanese patients with open-angle glaucoma

Nobuyuki Shoji; Masayuki Kasahara; Ayaka Iijima; Masahide Takahashi; Sonoko Tatsui; Kazuhiro Matsumura; Tetsuya Morita; Kimiya Shimizu


Japanese Journal of Ophthalmology | 2012

Silicone intraocular lens surface calcification in a patient with asteroid hyalosis

Kazuhiro Matsumura; Masahiko Takano; Kimiya Shimizu; Noriko Nemoto

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