Papers - Kurihara, Toshihide

Dose-dependent myopia-suppressing effect of 4-phenlybutyric acid eye drops in a mouse myopia model under masked condition

Ikeda SI, Sone K, Takai Y, Miyano T, Negishi K, Tsubota K, Kurihara T†

BMC Ophthalmol 25 ( 1 ) 383 2025.07

Last author, Corresponding author, Accepted

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Background: Myopia, characterized by excessive axial elongation of the eyeball, has become a significant global public health issue, particularly in Asia. Severe myopia increases the risk of ocular complications, including retinal degeneration and glaucoma. Recent studies have identified the role of scleral extracellular matrix remodeling and endoplasmic reticulum (ER) stress in myopia pathogenesis. Our previous study identified scleral ER stress as a critical factor in myopia development. This study aimed to investigate the therapeutic potential of 4-phenylbutyric acid (4-PBA), a chemical chaperone, in mitigating scleral ER stress and its effects on myopia progression in a mouse myopia model under masked condition. Methods: A lens-induced myopia (LIM) mouse model was utilized to evaluate the effects of 4-PBA administered as eye drops. Mice received varying concentrations of 4-PBA or phosphate-buffered saline (PBS) as a control. Changes in refractive error and axial length were measured to assess myopia progression. In addition, further experiments were also conducted under masked conditions, where the experimenter was unaware of the treatment was being applied, for the three conditions of 2%, 0.5% 4-PBA eye drops or vehicle treatment of LIM mice. Results: Administration of 4-PBA at concentrations of 0.5% and higher significantly suppressed the myopic shift in refraction and axial elongation associated with myopia compared to mice in the PBS control group. In a blinded, masked experiment, 2% and 0.5% 4-PBA eye drops also suppressed the progression of myopia in a dose-dependent manner. Conclusions: This study demonstrated that 4-PBA effectively mitigated myopia progression in a mouse model by targeting scleral ER stress. The dose-dependent suppression of myopic shifts and axial elongation under masked experimental condtion highlights the potential of 4-PBA as a therapeutic agent for managing myopia. These findings pave the way for further research and potential clinical applications in myopia treatment.

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Antibiotics-Induced Gut Microbiome Dysbiosis Affects Susceptibility to Minus Lens-Induced Myopia in Mice

Ikeda SI, Lee D, Chen J, Fukuda S, Negishi K, Tsubota K†, Kurihara T†

Invest Ophthal Vis Sci. (Association for Research in Vision and Ophthalmology (ARVO))  66 ( 6 ) 76 2025.06

Last author, Corresponding author, Accepted,  ISSN  1552-5783

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Evaluation of Anti-VEGFR2 Specific Photoimmunotherapy for Targeted Regression of Neovascularization in an AMD Model

Osada H, Nishimura T, Mitsunaga M, Saruta M, Tsubota K, Negishi K, Kurihara T, Ban N†

Invest Ophthalmol Vis Sci. (Association for Research in Vision and Ophthalmology (ARVO))  66 ( 6 ) 70 2025.06

Accepted,  ISSN  1552-5783

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Thicker peripapillary choroid may be associated with behavioral factors in Tokyo's children.

Hashimoto A*, Yotsukura E*, Ogawa M, Mori K, Hanyuda A, Tsubota K, Kurihara T, Negishi K†, Torii H†

Sci Rep. 15 ( 1 ) 17868 - 17868 2025.05

Accepted

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The study goals were measurement of the choroidal thickness (CT) and investigation of related factors among children. Third-grade students at an elementary school in Tokyo participated in this study. A total of 119 schoolchildren underwent measurements of the axial length (AL), non-cycloplegic objective refraction (SE), and CT. The CT was divided into nine regions: the subfoveal area with a diameter of 1 mm (C0), a 5-mm-diameter circle-C0 (C1), and a 9-mm-diameter circle (C2); each was further divided into four quadrants. The SE, AL, and C0 CT were, respectively, - 1.57 ± 1.56 diopters, 23.39 ± 0.80 mm, and 297.73 ± 57.88 μm. Multiple regression analysis showed that the time spent using a computer was associated significantly with the CT in the C0 and the inferior C2 (C0: β = -0.728, P = 0.028; inferior C2: β = -0.527, P = 0.048), and the reading distance was associated significantly with the CT in the superior and nasal C2 (superior, β = 1.664, P = 0.007; nasal, β = 1.128, P = 0.015). In addition, time spent using smartphones, tablets, or handheld gaming devices was associated significantly with the CT in the superior and inferior C2 (superior C2: β = 0.259, P = 0.018; inferior C2: β = 0.262, P = 0.013). In conclusion, reading distance and time spent on digital devices may be associated with choroid thickness in children.

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Intensive outdoor activity for 1 week increases choroidal thickness in Japanese schoolchildren: a prospective observational study

Ogawa M, Torii H†, Yotsukura E, Mori K, Hanyuda A, Matsumura J, Fukuoka K, Negishi K, Kurihara T†, Tsubota K†

BMC Ophthalmol. 25 ( 1 ) 300 2025.05

Corresponding author, Accepted

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Background: Outdoor activity is important to prevent myopia progression among schoolchildren, and maintaining the choroidal thickness is important to retard myopia progression. However, no research has reported the effects of short-term intensive outdoor activities on the choroidal thickness. This institution-based prospective observational study aims to assess the impact of outdoor activity for 1 week during a camp program to study ocular parameters including the choroidal thickness. Methods: The intensive outdoor activity program included an average of 6.15 ± 2.98 h of daily time spent outdoors during the camp on subsequent days for 1 week at a low-altitude mountain camp. Twenty-four children participated in this program. Results: The main outcome was the change in the choroidal thickness compared with baseline. The data were measured at the beginning and end of the program over the course of 1 week and the changes analyzed. The mean age of the participants (50% female) was 11.5 ± 0.5 (standard deviation) years, and the mean changes were as follows: the refractive error became more positive, the axial length decreased, and the choroidal thickness (µm) increased, respectively, by 0.21 ± 1.35 diopters (P = 0.742), -0.01 ± 0.02 mm (P = 0.241), and 30.7 ± 20.3 μm (P < 0.001). Conclusion: The results suggested that intensive outdoor activity for only 1 week increased the choroidal thickness in Japanese schoolchildren.

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Intraocular Vasculature Formation Precedes Extraocular Vasculature Penetration of Mouse Eyes

Imanishi S., Tomita Y., Negishi K., Tsubota K., Kurihara T†

SSRN  2025.05

Last author, Corresponding author

Assessing public awareness of myopia after the COVID-19 pandemic: an infodemiology study

Chen J, Lee D., Ikeda SI, Zhang Y., Negishi K., Tsubota K., Kurihara T†

BMJ Health Care Inform. 32 ( 1 ) e101156 2025.05

Last author, Corresponding author, Accepted

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Objectives Since the COVID-19 pandemic started, an increasing number of individuals use online resources to obtain health-related information, including myopia management. We aimed to obtain the search interest of global public health on myopia and prevention/treatment methods before and after the outbreak of COVID-19. Methods Google Trends was used to assess the global search interest in myopia and related terms. Data spanning from 2019 to 2023 were collected and segmented into three periods: prepandemic (2019), pandemic year (2020) and postpandemic (2021-2023). Each average search volume index was used to examine public awareness with the Kruskal-Wallis test. Results Among commonly used search keywords, Myopia is preferred over more colloquial terms (Nearsighted and Shortsighted). During the pandemic, searches for Myopia remained stable, while postpandemic, interest in Myopia surged (31.54%, p<0.0001). Myopia prevention/treatment awareness from 2019 to 2023 indicated notable shifts. In 2020, searches for Contact lenses and Spectacles decreased (-14.09% and -21.97%, respectively, both p<0.0001). These trends persisted postpandemic, with declining searches for Orthokeratology (-41.38%, p<0.01). Public interest for Light therapy (43.00%, p<0.0001) and Atropine (27.42%, p<0.0001) increased. Discussion The research highlights significant increases in global online awareness of myopia during the COVID-19 pandemic. The extended period of remote work during the pandemic may alter lifestyle habits and affect public perception of treatment options. Those findings could offer valuable perspectives on global interest patterns related to myopia, which supports subsequent myopia studies and is further useful to develop relevant public health policies.

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Unilateral Common Carotid Artery Occlusion in Adult Mice with Streptozotocin Comorbidity Leads to Early Retinal Inflammation

Gettinger K*, Lee D*, Negishi K, Kurihara T†

Int J Mol Sci. 26 ( 9 ) 4385 2025.05

Last author, Corresponding author, Accepted,  ISSN  16616596

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Diabetic retinopathy (DR) is a leading cause of visual impairment. To better understand the pathology, clinically relevant experimental models are needed. Widely used DR models (especially streptozotocin (STZ)-induced) require extended timeframes to reach DR phenotype endpoints and lack ischemic phenotypes, which are in contrast to the human condition. Unilateral common carotid artery occlusion (UCCAO) could provide a retinal ischemic insult. We explored the pathologic synergistic effects of UCCAO in STZ mice. STZ (90 mg/kg) was injected intraperitoneally into adult C57BL/6 mice for three days. Four weeks later, right UCCAO was performed. One week after UCCAO, retinal samples were stained with isolectin B4 to analyze cellular and vascular changes. Retinal samples were obtained one day and one week after UCCAO and quantitative PCR (qPCR) were performed to observe inflammatory and ischemic responses. Only the STZ UCCAO group showed increased inflammatory cells. STZ UCCAO retina demonstrated a significant difference in capillary and large vessel size compared to other groups. At one day and one week, there was a change in mRNA expressions in inflammatory genes Ccl2, Ccl12, Bnip3, Pdk1, Hsp25, and Vegfa in the STZ UCCAO group compared to other groups. Our model can serve as an accelerated DR model for studying inflammatory vascular changes.

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Violet Light Is Abundant Outdoors but Deficient Indoors in Modern Lifestyle in Tokyo

Kondo S*, Jiang X*, Torii H, Mori K, Negishi K, Kurihara T†, Tsubota K†

Int J Enviro Res Public Health. (MDPI AG)  22 ( 3 ) 444 - 444 2025.03

Corresponding author, Accepted,  ISSN  16617827

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This study examines the role of violet light (VL) in preventing myopia progression, addressing a critical need in urban environments where VL exposure is limited. Recent research suggests that VL, within the 360–400 nm wavelength range, may reduce myopia risk. To investigate, we conducted spectroscopic measurements in various settings across Tokyo, quantifying VL irradiance in natural sunlight. The results showed high VL levels outdoors, averaging 583 μW/cm2 on sunny days and 271 μW/cm2 on cloudy days, leading to a weighted annual average of approximately 310 μW/cm2. In contrast, indoor environments lacked VL due to UV-blocking materials in windows, glasses, and lighting. This deficiency may contribute to the rising incidence of myopia, particularly in urban areas with reduced outdoor exposure. Our findings highlight the need for innovative solutions to mitigate VL deficiency indoors, such as optimizing architectural designs and artificial lighting to better incorporate VL. This study provides foundational insights for future interventions aimed at reducing myopia risk through improved indoor light environments.

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第128回 日本眼科学会総会 評議員会指名講演II 視覚とニューロサイエンス 光生物学を基盤とした眼疾患病態生理の理解と治療開発

栗原俊英

日眼会誌 129 ( 3 ) 354 - 378 2025.03

Lead author, Last author, Corresponding author, Accepted

Axial Length Shortened in Approximately 20% of Patients Wearing Extended Depth-of-Focus Contact Lenses

Hazra D*, Yotsukura E*, Oyama S*, Shigeno Y, Mori K, Takeuchi R, Nakajima Y, Hanyuda A, Ogawa M, Kurihara T, Torii H†, Negishi K†

J Clin Med. 14 ( 5 ) 1750 2025.03

Accepted

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Background/Objectives: Preceding studies have reported the efficacy of multifocal contact lenses (MFCLs) in slowing myopia progression. Recently, a novel type of MFCL, i.e., extended depth-of-focus (EDOF) contact lens (CL), was designed. Here, we retrospectively investigated myopia progression associated with EDOF CL wear. Methods: Twenty-four consecutive myopic children (24 eyes; mean age, 13.9 years) received EDOF CLs to control myopia progression and participated in the study. We measured the axial length (AL), spherical equivalent (SE), and choroidal thickness (CT) at baseline and after 1 year of lens wear and compared the changes. Results: The mean baseline AL, SE, and CT were, respectively, 26.31 mm, −6.38 diopter (D), and 235 μm, and at 1 year 26.40 mm (p = 0.03), −6.61 D (p = 0.05), and 244 μm (p = 0.18). The AL decreased in 20.8% of cases (≧−0.05 mm/year), whereas 20.8% and 58.4% of cases had stabilization of the AL or an increased AL (≧+0.05 mm/year), respectively. The patients with a decreased AL engaged in a mean outdoor activity time of 200.6 min/day, the patients with an increased AL (≧+0.05 mm/year) engaged in a mean outdoor activity time of 126.7 min/day. The change in the AL was correlated significantly with the change in the CT (β = −0.46, p < 0.05), and 80% of patients with a shortened AL had increased CT (≧+20 μm/year). Conclusions: Our data showed that the AL stabilized or decreased in over 40% of myopic patients wearing EDOF CLs.

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Tropism of the AAV6.2 Vector in the Murine Retina

Suzuki R*, Katada Y*, Fujii M, Serizawa N, Negishi K, Kurihara T†

Int J Mol Sci. 26 ( 4 ) 1580 2025.02

Last author, Corresponding author, Accepted,  ISSN  16616596

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Retinitis pigmentosa (RP) is a progressive inherited retinal dystrophy (IRD) that primarily affects rod photoreceptor cells, leading to the degeneration of photoreceptors and the gradual loss of vision. While RP is one of the most studied IRDs, other neurodegenerative diseases affecting the retina and optic nerve, such as glaucoma, also involve common mechanisms of cellular stress and degeneration. Current therapeutic approaches under investigation include gene therapy, retina prosthesis, and neuroprotection. Among these approaches, gene therapy has shown promise, though challenges related to viral vector tropism and transduction efficiency persist. The adeno-associated virus (AAV) vector is commonly employed for gene delivery, but novel serotypes and engineered variants are being explored to improve specificity and efficacy. This study evaluates the gene transfer efficiency of the AAV6.2 vector following intravitreal injection into the murine retina. Male C57BL/6 mice (9 weeks old) were intravitreally injected with 1 µL of AAV2-CMV-EGFP, AAV6-CMV-EGFP, or AAV6.2-CMV-EGFP at a titer of 3.2 × 1012 vg/mL per eye. Retinal transduction was assessed using in vivo fluorescence imaging, flat-mount imaging, and immunohistochemistry. EGFP expression in retinal ganglion cells, Müller cells, amacrine cells, and bipolar cells was quantitatively analyzed. All three AAV serotypes effectively transduced retinal ganglion cells, but AAV6.2 exhibited enhanced transduction in Müller cells and other neuronal retinal cells, including bipolar and amacrine cells. AAV6.2 demonstrated more localized expression around retinal blood vessels compared to the diffuse expression observed with AAV2. Immunohistochemical analysis revealed that AAV6.2 had significantly higher transduction efficiency in Müller cells (p < 0.001) compared to AAV2 and AAV6. AAV6.2 shows superior transduction efficiency in Müller cells, positioning it as a promising vector for gene therapies targeting retinal degenerative diseases such as RP. Its ability to effectively transduce Müller cells suggests potential applications in neuroprotection and gene replacement therapies.

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幼少期の強膜穿孔創から58年経過して外因性細菌性眼内炎を発症した1例

上村綾音, 伴紀充, 國見洋光, 富田洋平, 栗原俊英, 篠田 肇, 根岸一乃

眼科臨床紀要 17 ( 10 ) 749 - 752 2024.12

Accepted

Acquisition of high-sensitivity human aqueous humor Raman spectra

Shinojima A, Sawada M, Kuroda M,Lee D, Kinoshita T, Negishi K, Kurihara T†

Res Sq.  2024.10

Last author, Corresponding author

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Deep Spectral Library of Mice Retina for Myopia Research: Proteomics Dataset generated by SWATH and DIA-NN

Sze YH, Tse DYY, Zuo B, Li KK, Zhao Q, Jiang X, Kurihara T, Tsubota K, Lam TC†

Sci Data. 11 ( 1 ) 1115 - 1115 2024.10

Accepted

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The retina plays a crucial role in processing and decoding visual information, both in normal development and during myopia progression. Recent advancements have introduced a library-independent approach for data-independent acquisition (DIA) analyses. This study demonstrates deep proteome identification and quantification in individual mice retinas during myopia development, with an average of 6,263 ± 86 unique protein groups. We anticipate that the use of a predicted retinal-specific spectral library combined with the robust quantification achieved within this dataset will contribute to a better understanding of the proteome complexity. Furthermore, a comprehensive mice retinal-specific spectral library was generated, encompassing a total identification of 9,401 protein groups, 70,041 peptides, 95,339 precursors, and 761,868 transitions acquired using SWATH-MS acquisition on a ZenoTOF 7600 mass spectrometer. This dataset surpasses the spectral library generated through high-pH reversed-phase fractionation by data-dependent acquisition (DDA). The data is available via ProteomeXchange with the identifier PXD046983. It will also serve as an indispensable reference for investigations in myopia research and other retinal or neurological diseases.

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Myopic shift in female mice after ovariectomy

Zhang Y, Mori K, Jeong H, Chen J, Liang Y, Negishi K, Tsubota K†, Kurihara T†

Sci Rep. 14 ( 1 ) 22946 - 22946 2024.10

Last author, Corresponding author, Accepted

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Myopia is a global public health concern, with a higher prevalence in women than that in male. As the relationship between sex hormone and myopia remains unclear, we aimed to reveal the relationship between sex hormone and myopia by removing the ovaries of mice and measuring changes in ocular parameters related to myopia. Lens-induced myopia (LIM) surgeries were performed on 3-week-old male mice and age-matched female mice to evaluate the effects of sex on myopia development, which indicated a high degree of myopia and rapid progression of axial elongation in male mice. Bilateral ovariectomy (OVX) performed on 4-week-old female mice induced myopic refraction status in ovariectomized mice. Although axial length elongation was larger in ovariectomized mice than that in sham control mice, the result was insignificant. To further reveal the relationship between female sex hormones and myopia, LIM combined with OVX was performed, which revealed a magnified myopic refraction status in ovariectomized mice. Nevertheless, elongation of the anterior chamber depth in the - 30 D lens-treated eyes significantly increased in LIM + OVX mice compared with the frame-treated eyes in LIM + OVX mice and - 30 D lens-treated eyes in LIM + Sham surgery mice. Sex hormones play a role in regulating myopia development in female mice.

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Recent Insights into Roles of Hypoxia-Inducible Factors in Retinal Diseases

Lee D, Tomita Y, Miwa Y, Kunimi H, Nakai A, Shoda C, Negishi K, Kurihara T†

Int J Mol Sci. 25 ( 18 ) 10140 2024.09

Last author, Corresponding author, Accepted,  ISSN  16616596

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Hypoxia-inducible factors (HIFs) are transcriptional factors that function as strong regulators of oxygen homeostasis and cellular metabolisms. The maintenance of cellular oxygen levels is critical as either insufficient or excessive oxygen affects development and physiologic and pathologic conditions. In the eye, retinas have a high metabolic demand for oxygen. Retinal ischemia can cause visual impairment in various sight-threating disorders including age-related macular degeneration, diabetic retinopathy, and some types of glaucoma. Therefore, understanding the potential roles of HIFs in the retina is highly important for managing disease development and progression. This review focuses on the physiologic and pathologic roles of HIFs as regulators of oxygen homeostasis and cellular metabolism in the retina, drawing on recent evidence. Our summary will promote comprehensive approaches to targeting HIFs for therapeutic purposes in retinal diseases.

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Fundus Image Analysis of Retinitis Pigmentosa Using Artificial Intelligence

Ubukata S*, Masayoshi K*, Katada Y†, Yang L, Ozawa N, Ibuki M, Negishi K, Kurihara T†

Res Sq.  2024.09

Last author, Corresponding author

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Establishment of an in vitro choroid complex system for vascular response screening

Jeong H, Lee D, Negishi K, Tsubota K†, Kurihara T†

Sci Rep. 14 ( 1 ) 16129 2024.07

Corresponding author, Accepted

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The choroid, a vascularized tissue situated between the retina and the sclera, plays a crucial role in maintaining ocular homeostasis. Despite its significance, research on choroidal abnormalities and the establishment of effective in vitro models have been limited. In this study, we developed an in vitro choroid model through the co-culture of human induced pluripotent stem cells (hiPSC)-derived endothelial cells (ECs) and mouse choroidal fibroblasts (msCFs) with hiPSC-derived retinal pigment epithelial (RPE) cells via a permeable membrane. This model, inclusive of ECs, CFs, and RPE cells, exhibited similarities with in vivo choroidal vessels, as confirmed through immunohistochemistry of extracellular matrix markers and vascular-related markers, as well as choroid angiogenesis sprouting assay analysis. The effectiveness of our in vitro model was demonstrated in assessing vascular changes induced by drugs targeting vasoregulation. Our model offers a valuable tool for gaining insights into the pathological mechanisms underlying choroid development and the progression of choroidal vascular diseases.

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Long-term Outcomes of Anti-Vascular Endothelial Growth Factor Drug Therapies for Neovascular Age-related Macular Degeneration Based on its Subtypes

Kato S, Uchida A†, Nagai N, Suzuki M, Minami S, Shinojima A, Ban N, Horiuchi N, Fujioka S,Kurihara T, Shinoda H, Ozawa Y, Negishi K

J Jpn Ophthalmol Soc. 128 ( 6 ) 473 - 486 2024.06

Accepted