Details of the Researcher

PHOTO

Masataka Sato
Section
Tohoku University Hospital
Job title
Assistant Professor

Papers 10

  1. Oxidative Stress in Glaucoma: From Pathogenic Mechanisms to Emerging Antioxidant Therapies. International-journal

    Akiko Hanyuda, Satoru Tsuda, Naoki Takahashi, Masataka Sato, Kota Sato, Noriko Himori, Toru Nakazawa

    Antioxidants (Basel, Switzerland) 15 (6) 2026/06/14

    DOI: 10.3390/antiox15060751  

    eISSN: 2076-3921

  2. Portable AI-powered scanning slit-light device for low-cost eye disease screening. International-journal

    Neelam Kaushik, Parmanand Sharma, Takehiro Miya, Noriko Himori, Masataka Sato, Satoru Tsuda, Toru Nakazawa

    Scientific reports 2026/03/17

    DOI: 10.1038/s41598-026-44392-w  

  3. Detection of Cataract with a New Perimetry Method Using Retinal Projection Technology.

    Takeshi Yabana, Naoko Takada, Satoru Tsuda, Makoto Ishikawa, Mai Yamazaki, Masataka Sato, Takahiro Ninomiya, Yu Yokoyama, Noriko Himori, Kazuki Hashimoto, Aki Osanai, Seiji Morino, Makoto Suzuki, Mitsuru Sugawara, Hiroshi Kunikata, Toru Nakazawa

    The Tohoku journal of experimental medicine 2025/06/05

    DOI: 10.1620/tjem.2025.J066  

  4. Development of a Low-Cost Scanning Laser Ophthalmoscope Using Semiconductor Laser Technology.

    Hiroki Takizawa, Hiroshi Kunikata, Takeshi Yabana, Masataka Sato, Takahiro Ninomiya, Neelam Kaushik, Parmanand Sharma, Noriko Himori, Mitsuru Sugawara, Seiji Morino, Makoto Suzuki, Makoto Ishikawa, Toru Nakazawa

    The Tohoku journal of experimental medicine 265 (1) 39-45 2025/03/06

    DOI: 10.1620/tjem.2024.J072  

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    In recent years, the use of scanning laser ophthalmoscopy (SLO) has emerged as a valuable tool in ophthalmic diagnostics. However, its widespread adoption has been prevented by substantial costs associated with existing devices. This study reports on the development of a low-cost SLO that is safe, requires no pupil dilation and no focus adjustment, and uses semiconductor laser technology for scanning. A prototype SLO equipped with red (638 nm) and infrared (IR; 795 nm) lasers was developed, and eyes with ocular diseases including glaucoma, branch retinal vein occlusion (BRVO), and diabetic retinopathy (DR) were examined using the SLO. We examined 53 patients (average age 62.0 ± 13.0 years; 93 eyes) with glaucoma (65 eyes), BRVO (11 eyes), and DR (17 eyes) using the low-cost SLO. Successful images were obtained from 83 eyes of 47 patients. The process was non-invasive, allowing for clear observation of the optic nerve head (ONH) and retinal vessels using both red and IR lasers. Furthermore, ophthalmological findings such as ONH cupping, macular edema, and retinal hemorrhage were detectable. Using a semiconductor laser, the prototype SLO successfully obtained high-quality images of ocular morphology and pathology without requiring pupil dilation and without focus adjustment. This low-cost SLO has the potential to enhance the accessibility of ophthalmic diagnostics, particularly in resource-limited settings, and contribute to the early detection and management of various ocular diseases.

  5. A hybrid multi model artificial intelligence approach for glaucoma screening using fundus images. International-journal

    Parmanand Sharma, Naoki Takahashi, Takahiro Ninomiya, Masataka Sato, Takehiro Miya, Satoru Tsuda, Toru Nakazawa

    NPJ digital medicine 8 (1) 130-130 2025/02/27

    DOI: 10.1038/s41746-025-01473-w  

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    Glaucoma, a leading cause of blindness, requires accurate early detection. We present an AI-based Glaucoma Screening (AI-GS) network comprising six lightweight deep learning models (total size: 110 MB) that analyze fundus images to identify early structural signs such as optic disc cupping, hemorrhages, and nerve fiber layer defects. The segmentation of the optic cup and disc closely matches that of expert ophthalmologists. AI-GS achieved a sensitivity of 0.9352 (95% CI 0.9277-0.9435) at 95% specificity. In real-world testing, sensitivity dropped to 0.5652 (95% CI 0.5218-0.6058) at ~0.9376 specificity (95% CI 0.9174-0.9562) for the standalone binary glaucoma classification model, whereas the full AI-GS network maintained higher sensitivity (0.8053, 95% CI 0.7704-0.8382) with good specificity (0.9112, 95% CI 0.8887-0.9356). The sub-models in AI-GS, with enhanced capabilities in detecting early glaucoma-related structural changes, drive these improvements. With low computational demands and tunable detection parameters, AI-GS promises widespread glaucoma screening, portable device integration, and improved understanding of disease progression.

  6. Genetic Risk Stratification of Primary Open-Angle Glaucoma in Japanese Individuals. International-journal

    Masato Akiyama, Gen Tamiya, Kohta Fujiwara, Yukihiro Shiga, Yu Yokoyama, Kazuki Hashimoto, Masataka Sato, Kota Sato, Akira Narita, Sawako Hashimoto, Emi Ueda, Yoshihiko Furuta, Jun Hata, Masahiro Miyake, Hanako O Ikeda, Kenji Suda, Shogo Numa, Yuki Mori, Kazuya Morino, Yusuke Murakami, Sakurako Shimokawa, Shun Nakamura, Nobuyo Yawata, Kimihiko Fujisawa, Satoshi Yamana, Kenichiro Mori, Yasuhiro Ikeda, Kazunori Miyata, Keisuke Mori, Ken Ogino, Yoshito Koyanagi, Yoichiro Kamatani, Toshiharu Ninomiya, Koh-Hei Sonoda, Toru Nakazawa

    Ophthalmology 131 (11) 1271-1280 2024/11

    DOI: 10.1016/j.ophtha.2024.05.026  

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    PURPOSE: To assess the impact of genetic risk estimation for primary open-angle glaucoma (POAG) in Japanese individuals. DESIGN: Cross-sectional analysis. PARTICIPANTS: Genetic risk scores (GRSs) were constructed based on a genome-wide association study (GWAS) of POAG in Japanese people. A total of 3625 Japanese individuals, including 1191 patients and 2434 controls (Japanese Tohoku), were used for the model selection. We also evaluated the discriminative accuracy of constructed GRSs in a dataset comprising 1034 patients and 1147 controls (the Japan Glaucoma Society Omics Group [JGS-OG] and the Genomic Research Committee of the Japanese Ophthalmological Society [GRC-JOS]) and 1900 participants from a population-based study (Hisayama Study). METHODS: We evaluated 2 types of GRSs: polygenic risk scores using the pruning and thresholding procedure and a GRS using variants associated with POAG in the GWAS of the International Glaucoma Genetics Consortium (IGGC). We selected the model with the highest areas under the receiver operating characteristic curve (AUC). In the population-based study, we evaluated the correlations between GRS and ocular measurements. MAIN OUTCOME MEASURE: Proportion of patients with POAG after stratification according to the GRS. RESULTS: We found that a GRS using 98 variants, which showed genome-wide significance in the IGGC, showed the best discriminative accuracy (AUC, 0.65). In the Japanese Tohoku, the proportion of patients with POAG in the top 10% individuals was significantly higher than that in the lowest 10% (odds ratio [OR], 6.15; 95% confidence interval [CI], 4.35-8.71). In the JGS-OG and GRC-JOS, we confirmed similar impact of POAG GRS (AUC, 0.64; OR [top vs. bottom decile], 5.81; 95% CI, 3.79-9.01). In the population-based study, POAG prevalence was significantly higher in the top 20% individuals of the GRS compared with the bottom 20% (9.2% vs. 5.0%). However, the discriminative accuracy was low (AUC, 0.56). The POAG GRS was correlated positively with intraocular pressure (r = 0.08: P = 4.0 × 10-4) and vertical cup-to-disc ratio (r = 0.11; P = 4.0 × 10-6). CONCLUSIONS: The GRS showed moderate discriminative accuracy for POAG in the Japanese population. However, risk stratification in the general population showed relatively weak discriminative performance. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

  7. Detection of cataract with MEOCHECK, a simple visual field measurement device using retinal projection technology

    Tadashi Nakashima, Takeshi Yabana, Masataka Sato, Takahiro Ninomiya, Mai Yamazaki, Noriko Himori, Morino Seiji, Makoto Suzuki, Satoru Tsuda, Yu Yokoyama, Makoto Ishikawa, Hiroshi Kunikata, Toru Nakazawa

    INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE 65 (7) 2024/06

    ISSN: 0146-0404

    eISSN: 1552-5783

  8. The association between intraocular pressure dynamics during dark-room prone testing and intraocular pressure over a relatively long-term follow-up period in primary open-glaucoma patients. International-journal

    Masataka Sato, Naoki Kiyota, Takeshi Yabana, Shigeto Maekawa, Satoru Tsuda, Kazuko Omodaka, Noriko Himori, Yu Yokoyama, Toru Nakazawa

    Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie 262 (3) 949-956 2024/03

    DOI: 10.1007/s00417-023-06257-0  

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    PURPOSE: To investigate the relationship between the dynamics of intraocular pressure (IOP) during dark-room prone testing (DRPT) and IOP over a relatively long-term follow-up period. METHODS: This retrospective study enrolled 84 eyes of 51 primary open-angle glaucoma patients who underwent DRPT for whom at least three IOP measurements made using Goldmann applanation tonometry were available over a maximum follow-up period of two years. We excluded eyes with a history of intraocular surgery or laser treatment and those with changes in topical anti-glaucoma medication during the follow-up period. In DRPT, IOP was measured in the sitting position, and after 60 min in the prone position in a dark room, IOP was measured again. In this study, IOP fluctuation refers to the standard deviation (SD) of IOP, and IOP max indicates the maximum value of IOP during the follow-up. The relationship between these parameters was analyzed with a linear mixed-effects model, adjusting for clinical parameters including age, gender, and axial length. RESULTS: IOP increased after DRPT with a mean of 6.13 ± 3.55 mmHg. IOP max was significantly associated with IOP after DRPT (β = 0.38; p < 0.001). IOP fluctuation was significantly associated with IOP change in DRPT (β = 0.29; p = 0.007). CONCLUSION: Our findings suggest that short-term and relatively long-term IOP dynamics are associated. Long-term IOP dynamics can be predicted by DRPT to some extent.

  9. Sector-specific Association of Intraocular Pressure Dynamics in Dark-room Prone Testing and Visual Field Defect Progression in Glaucoma. International-journal

    Masataka Sato, Naoki Kiyota, Takeshi Yabana, Shigeto Maekawa, Satoru Tsuda, Kazuko Omodaka, Noriko Himori, Yu Yokoyama, Toru Nakazawa

    Ophthalmology. Glaucoma 7 (4) 372-379 2024

    DOI: 10.1016/j.ogla.2024.03.007  

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    PURPOSE: To investigate sectoral differences in the relationship between intraocular pressure (IOP) dynamics during dark-room prone testing (DRPT) and visual field (VF) defect progression in primary open-angle glaucoma (POAG) patients. DESIGN: Retrospective, longitudinal study. PARTICIPANTS: This retrospective study included 116 eyes of 84 POAG patients who underwent DRPT and had at least 5 reliable VF tests conducted over a more than 2-year follow-up period. We excluded eyes with mean deviation worse than -20 dB or a history of intraocular surgery or laser treatment. METHODS: Average total deviation (TD) was calculated in the superior, central, and inferior sectors of the Humphrey 24-2 or 30-2 program. During DRPT, IOP was measured in the sitting position, and after 60 minutes in the prone position in a dark room, IOP was measured again. The relationship between IOP change during DRPT, IOP after DRPT, and TD slope in each quadrant was analyzed with a linear mixed-effects model, adjusting for other potential confounding factors. MAIN OUTCOME MEASURES: Total deviation slope in each quadrant, IOP change during DRPT, and IOP after DRPT. RESULTS: Intraocular pressure after DRPT and IOP change during DRPT were 18.16 ± 3.42 mmHg and 4.92 ± 3.12 mmHg, respectively. Superior TD slope was significantly associated with both IOP after DRPT (β = -0.28, P = 0.003) and IOP change during DRPT (β = -0.21, P = 0.029), while central (β = -0.05, P = 0.595; β = -0.05; P = 0.622) and inferior (β = 0.05, P = 0.611; β = 0.01, P = 0.938) TD slopes were not. CONCLUSION: Dark-room prone testing might be a useful test to predict the risk of superior VF defect progression in eyes with POAG. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

  10. Sex differences in the association between systemic oxidative stress status and optic nerve head blood flow in normal-tension glaucoma. International-journal

    Masataka Sato, Masayuki Yasuda, Nana Takahashi, Kazuki Hashimoto, Noriko Himori, Toru Nakazawa

    PloS one 18 (2) e0282047 2023

    DOI: 10.1371/journal.pone.0282047  

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    PURPOSE: To investigate the association of systemic oxidative stress markers and optic nerve head (ONH) blood flow in normal-tension glaucoma (NTG) patients, as well as sex differences in this association. METHODS: This was a cross-sectional study of 235 eyes with NTG of 134 patients (56 male, 78 female; mean age, 60.9±14.1 years). Laser speckle flowgraphy (LSFG) was used to measure ONH blood flow (mean blur rate in the tissue area of the ONH; MBR-T) and LSFG pulse-waveform parameters, including flow acceleration index in the tissue area of the ONH (FAI-T). Oxidative stress markers, diacron-reactive oxygen metabolites (d-ROMs), and biological antioxidant potential (BAP) were measured with a free radical elective evaluator. Spearman's rank correlation test and a multivariate linear mixed-effect model were used to investigate factors associated with ONH blood flow. RESULTS: MBR-T was significantly correlated with age (rs = -0.28, p < 0.001), mean arterial pressure (rs = -0.20, p = 0.002), intraocular pressure (rs = 0.24, p < 0.001), peripapillary retinal nerve fiber layer thickness (rs = 0.62, p < 0.001), and disc area (rs = -0.26, p < 0.001), but not with serum d-ROM level. Separate analyses of the subjects divided by sex showed that BAP was positively correlated to MBR-T (rs = 0.21, p = 0.036) and FAI-T (rs = 0.36, p < 0.001) only in male subjects. Similarly, BAP was significantly associated with MBR-T (β = 0.25, p = 0.026) and FAI-T (β = 0.37, p < 0.001) in male subjects in a multivariate linear mixed-effect model. CONCLUSION: A lower serum antioxidant level, as indicated by BAP, was associated with reduced ONH blood flow only in male NTG patients. Our findings suggest that there are sex differences in the involvement of oxidative stress in the pathogenesis of reduced ocular blood flow in NTG.

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Misc. 7

  1. The Study design and the progress report of the “Multicenter Ophthalmic Biobank”

    横山悠, 佐藤孝太, 橋本和軌, 高橋直樹, 佐藤正隆, 高田菜生子, 中澤徹

    日本緑内障学会抄録集 34回 223-223 2023/09

    Publisher: 日本緑内障学会

  2. Sector Differences in Visual Field Associations with Intraocular Pressure Changes by Prone Test

    佐藤正隆, 清田直樹, 矢花武史, 前川重人, 津田聡, 面高宗子, 檜森紀子, 横山悠, 中澤徹

    日本緑内障学会抄録集 34回 148-148 2023/09

    Publisher: 日本緑内障学会

  3. The Study design and the progress report of the “Multicenter Ophthalmic Biobank”

    横山悠, 佐藤孝太, 橋本和軌, 高橋直樹, 佐藤正隆, 高田菜生子, 中澤徹

    日本緑内障学会抄録集 34回 223-223 2023/09

    Publisher: 日本緑内障学会

  4. Intraocular pressure dynamics during the prone position and the follow-up term

    佐藤正隆, 清田直樹, 矢花武史, 前川重人, 津田聡, 面高宗子, 檜森紀子, 檜森紀子, 横山悠, 中澤徹

    日本眼科学会雑誌 127 (臨増) 188-188 2023/03

    Publisher: (公財)日本眼科学会

    ISSN: 0029-0203

  5. Factors associated with sinkhole formation in intrachoroidal cavitation

    山口知暁, 清田直樹, 高橋直樹, 武田瑶子, 佐藤正隆, 津田聡, 面高宗子, 中澤徹

    日本眼科学会雑誌 127 (臨増) 190-190 2023/03

    Publisher: (公財)日本眼科学会

    ISSN: 0029-0203

  6. Examination of the axial length in patients with angle closure with plateau iris

    佐久間大輔, 矢花武史, 佐藤正隆, 清田直樹, 津田聡, 横山悠, 中澤徹

    日本緑内障学会抄録集 33回 142-142 2022/09

    Publisher: 日本緑内障学会

  7. 正常眼圧緑内障患者における酸化ストレスマーカーと視神経乳頭血流の関連

    佐藤 正隆, 安田 正幸, 高橋 成奈, 橋本 和軌, 檜森 紀子, 中澤 徹

    日本緑内障学会抄録集 32回 80-80 2021/09

    Publisher: 日本緑内障学会

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