Kojima, Takashi



School of Medicine, Department of Ophthalmology (Shinanomachi)


Project Associate Professor (Non-tenured)


Papers 【 Display / hide

  • Posterior Chamber Phakic Intraocular Lens Implantation in Eyes with an Anterior Chamber Depth of Less Than 3 mm: A Multicenter Study

    Kamiya, K., Shimizu, K., Igarashi, A., Kitazawa, Y., Kojima, T., Nakamura, T. and Ichikawa, K.

    Sci Rep 8 ( 1 ) 13322 2018.09

    ISSN  2045-2322

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    This study was aimed to assess the clinical outcomes of Visian ICL (hole ICL; STAAR Surgical, Inc.) implantation for the correction of myopic refractive errors in eyes having an anterior chamber depth (ACD) below the current manufacturer's recommendation (<3.0 mm). We comprised 365 eyes of 201 consecutive patients (mean age +/- standard deviation, 35.7 +/- 7.5 years) with spherical equivalents of -8.66 +/- 3.54 D. We evaluated the safety, efficacy, predictability, stability, intraocular pressure (IOP), endothelial cell density (ECD), and complications. The safety and efficacy indices were 1.12 +/- 0.22 and 0.98 +/- 0.22. At 1 year, 90% and 98% of eyes were within +/- 0.5 and 1.0 D of the attempted correction, respectively. Changes in the manifest refraction from 1 week to 1 year postoperatively were -0.08 +/- 0.34 D. The mean ECD loss was 0.2 +/- 8.7%. No eyes showed a significant ECD loss (>/=30%). We found no significant correlation between the ACD and the change in ECD (Pearson correlation coefficient r = -0.048, p = 0.360). No significant IOP rise or vision-threatening complication occurred at any time. These findings indicate that the surgical indication of ICL implantation should be reconsidered in terms of ACD.

  • Refractive Outcomes After Phototherapeutic Refractive Keratectomy for Granular Corneal Dystrophy

    Nakamura, T., Kataoka, T., Kojima, T., Yoshida, Y. and Sugiyama, Y.

    Cornea 37 ( 5 ) 548 - 553 2018.05

    ISSN  0277-3740

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    PURPOSE: This retrospective study aimed to evaluate the effectiveness of a novel procedure named phototherapeutic refractive keratectomy (PTRK), which is a sequential procedure composed of phototherapeutic keratectomy ablation for removal of opacities, followed by smoothing ablation for reducing the corneal surface irregularities and photorefractive keratectomy ablation for correcting refractive errors in eyes with primary granular corneal dystrophy. METHODS: Twenty-three eyes of 17 patients with granular corneal dystrophy were treated with PTRK. Preoperative and postoperative visual acuity, corneal topography, and changes in spherical equivalent and cylindrical refraction were examined and analyzed. RESULTS: The mean spherical equivalent power changed from -0.11 +/- 1.36 diopters (D) to 0.19 +/- 0.91 D postoperatively (P = 0.121). The change in the mean spherical equivalent was +0.30 +/- 0.99 D. The mean preoperative uncorrected distance visual acuity (logMAR) of 0.40 +/- 0.26 significantly improved to 0.075 +/- 0.145 at 3 months after PTRK (P < 0.001). The mean preoperative corrected distance visual acuity (logMAR) of 0.18 +/- 0.17 significantly improved to -0.02 +/- 0.11 at 3 months after PTRK (P < 0.01). The surface regularity index was significantly decreased from 0.93 +/- 0.46 preoperatively to 0.60 +/- 0.30 postoperatively (P < 0.001). CONCLUSIONS: Our results showed that PTRK could improve corneal surface irregularities and remove opacities. Furthermore, both corrected visual acuity and uncorrected visual acuity improved by the addition of refractive correction. PTRK is a promising surgical procedure for improving postoperative quality of life with a high degree of patient satisfaction.

  • Alterations of Murine Subbasal Corneal Nerves After Environmental Dry Eye Stress

    Simsek, C., Kojima, T., Dogru, M. and Tsubota, K.

    Invest Ophthalmol Vis Sci 59 ( 5 ) 1986 - 1995 2018.04

    ISSN  0146-0404

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    Purpose: To investigate the morphologic changes in the corneal subbasal nerve (CSN) plexus in wild-type mice after exposure to environmental dry eye stress (EDES) using in vivo confocal microscopy (IVCM). Methods: We examined 22 eyes of 8-week-old wild-type male mice (Balb/c, n = 11). The mice were exposed to an air fan inside a small compartment 5 hours/day for 3 days (EDES). Aqueous tear secretion and corneal epithelial damage were assessed. The CSNs were investigated by laser-scanning IVCM. Density; tortuosity; and reflectivity of CSNs; and dendritic cell (DC) densities were evaluated using semi-automated NeuronJ software. Results: EDES significantly decreased the aqueous tear secretion quantity (P = 0.0019) and significantly increased the corneal fluorescein (P = 0.005) and lissamine green staining scores (P = 0003). The CSN density showed a significant decrease after EDES exposure (before, 2813 +/- 762 pixels/frame; after, 1906 +/- 896 pixels/frame, P = 0.0071). The tortuosity and the reflectivity grades did not show statistically significant differences after EDES exposure (tortuosity, P = 0.307; reflectivity, P = 0.758). However, the mean DC density showed a significant increase after EDES exposure (before, 12.62 +/- 5.94 cells/mm2; after, 15.93 +/- 5.30 cells/mm2, P = 0.026). Conclusions: Even short-term exposure to EDES induced alterations in the CSN plexus morphology including decreased subbasal corneal nerve density and increased amount of DCs in mice. The EDES mouse model is a promising model to study the ocular surface and corneal nerve changes associated with dry eye disease.

  • The effects of 3% diquafosol sodium eye drop application on meibomian gland and ocular surface alterations in the Cu, Zn-superoxide dismutase-1 (Sod1) knockout mice

    Ikeda, K., Simsek, C., Kojima, T., Higa, K., Kawashima, M., Dogru, M., Shimizu, T., Tsubota, K. and Shimazaki, J.

    Graefes Arch Clin Exp Ophthalmol 256 ( 4 ) 739 - 750 2018.04

    ISSN  0721-832

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    PURPOSE: The purpose of the study is to investigate the effect of 3% diquafosol sodium eye drops on meibomian gland and ocular surface alterations in the superoxide dismutase-1 (Sod1 (-/-) ) mice in comparison to the wild-type mouse. METHODS: Three percent diquafosol sodium eye drop was instilled to 20 eyes of 10 50-week-old male Sod1 (-/-) mice and 22 eyes of 11 C57BL/6 strain 50-week-old wild-type (WT) male mice six times a day for 2 weeks. Aqueous tear secretion quantity was measured with phenol red-impregnated cotton threads without anesthesia. Tear film stability and corneal epithelial damage were assessed by fluorescein and lissamine green staining. We also performed oil red O (ORO) lipid staining to evaluate the lipid changes in the meibomian glands. Meibomian gland specimens underwent hematoxylin and eosin staining to examine histopathological changes and meibomian gland acinar unit density after sacrifice. Immunohistochemistry staining was performed using cytokeratin 4, cytokeratin 13, and transglutaminase-1 antibodies. Quantitative real-time polymerase chain reaction for cytokeratin 4, cytokeratin 13, and transglutaminase-1 mRNA expression was also performed. RESULTS: The aqueous tear quantity, the mean tear film breakup time, and the number of lipid droplets significantly improved in the Sod1 (-/-) mice with treatment. The mean meibomian acinar unit density did not change in the Sod1 (-/-) mice and WT mice after treatment. Application of 3% diquafosol sodium eye drop significantly decreased the corneal fluorescein and lissamine green staining scores in the Sod1 (-/-) mice after 2 weeks. We showed a notable increase in cytokeratin 4, cytokeratin 13 immunohistochemistry staining, and cytokeratin 4, cytokeratin 13 mRNA expressions with a marked decrease in immunohistochemistry staining and significant decline in mRNA expression of transglutaminase-1 after 3% diquafosol sodium treatment. CONCLUSION: Topical application of 3% diquafosol sodium eye drop improved the number of lipid droplets, tear stability, and tear production which in turn appeared to have a favorable effect on the ocular surface epithelium. Three percent diquafosol sodium eye drop may be a potential treatment for age-related meibomian gland and dry eye disease based on the observations of the current study.


    Kaga, T., Yokoyama, S., Kojima, T., Mitamura, H., Mori, T., Matsuda, T., Sato, H., Yoshida, N. and Ichikawa, K.

    Retina  2018.03

    ISSN  0275-004

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    PURPOSE: The purpose of this study was to investigate the clinical outcomes of novel endoscope-assisted vitreous surgery techniques in patients with rhegmatogenous retinal detachment complicated by Grade C proliferative vitreoretinopathy. METHODS: Eight consecutive patients who had undergone endoscope-assisted vitreous surgery for rhegmatogenous retinal detachment complicated by Grade C proliferative vitreoretinopathy were investigated. The peripheral vitreous was cut under air with the aid of endoscopic view (atmospheric endoscopic technique), and the subretinal proliferation was removed under subretinal endoscopic observation (subretinal endoscopic technique). RESULTS: Retinal reattachment was achieved after the primary surgery without a large retinotomy and scleral buckling in each case. The mean follow-up was 16.8 months (range, 8-28 months). Atmospheric endoscopic technique was performed in all cases, and subretinal endoscopic technique was performed in three cases. After surgery, the mean best-corrected visual acuity significantly improved from 20/778 to 20/111 (P = 0.014). Although microretinal breaks occurred during the removal of vitreous using atmospheric endoscopic technique in all cases, there were no severe postoperative complications, such as retinal detachment or proliferative vitreoretinopathy. CONCLUSION: Endoscope-assisted vitreous surgery with atmospheric endoscopic technique and/or subretinal endoscopic technique is safe and effective in the treatment of rhegmatogenous retinal detachment with Grade C proliferative vitreoretinopathy.

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • Neuroprotective function of Nrf2-Keap1 system in dry eye disease


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 小島 隆司, Grant-in-Aid for Scientific Research (C), Principal Investigator