| Project/Area Number |
15209056
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ophthalmology
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| Research Institution | Osaka University |
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Principal Investigator |
TANO Yasuo Osaka University, Graduate School of Medicine, Professor, 医学系研究科, 教授 (80093433)
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| Co-Investigator(Kenkyū-buntansha) |
FUJIKADO Takashi Osaka University, Graduate School of Medicine, Professor, 医学系研究科, 教授 (50243233)
YAGI Tetsuya Osaka University, Graduate School of Engineering, Professor, 工学研究科, 教授 (50183976)
OHJI Masahito Shiga University of Medical Science, Professor, 医学部, 教授 (90252650)
KAMEI Motohiro Osaka University, Graduate School of Medicine, Associate Professor, 医学系研究科, 助教授 (40281125)
MIYOSHI Tomomitu Osaka University, Graduate School of Medicine, Assistant, 医学系研究科, 助手 (70314309)
大鳥 安正 大阪大学, 医学系研究科, 講師 (40303953)
生野 恭司 大阪大学, 医学系研究科, 助手 (50294096)
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| Project Period (FY) |
2003 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥46,540,000 (Direct Cost: ¥35,800,000、Indirect Cost: ¥10,740,000)
Fiscal Year 2005: ¥9,620,000 (Direct Cost: ¥7,400,000、Indirect Cost: ¥2,220,000)
Fiscal Year 2004: ¥14,430,000 (Direct Cost: ¥11,100,000、Indirect Cost: ¥3,330,000)
Fiscal Year 2003: ¥22,490,000 (Direct Cost: ¥17,300,000、Indirect Cost: ¥5,190,000)
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| Keywords | Electrically evoked potential / Electrical stimulation / Electrode / Optic nerve / Visual prosthesis / Artificial Vision / パリレン / PDGF / 視神経乳頭 / 25ゲージ硝子体手術システム / MAPK / 針型電極 |
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| Research Abstract |
Purpose : To determine the safety and efficacy of transsclerally placed intrapapillary wire microelectrodes implanted chronically into the optic nerve head.
Methods : Platinum wire microelectrodes were passed through the sclera and implanted into the optic nerve head of five rabbit eyes for 4-6 months. Color fundus photography, fluorescein angiography, electroretinograms (ERGs), and visually evoked potentials (VEPs) were used to monitor the retina. Electrically evoked potentials (EEPs) were elicited by bipolar electrical stimulation of the optic nerve axons by different combinations of the four electrodes immediately after the implantation and at 1-month intervals thereafter. The effects of the chronic implantation of the electrodes on the morphology of the optic nerve were evaluated by histological and immunohistochemical examinations at 4 and 6 months after the implantation.
Results : All of the electrodes remained stable in the implanted sites throughout the post-implantation period,
… More
except for one electrode that had pulled out of the optic nerve head at 1 month after implantation. No intraocular infection, inflammation, or vitreoretinal proliferation was observed in any eye. EEPs could be elicited from each pair of electrodes at all testing times. The mean threshold currents (charge densities) to evoke EEPs increased at 1 month after implantation, but did not change significantly thereafter. The implicit time and amplitude of the a- and b-waves of the ERGs and of P1 of the VEPs did not change significantly throughout the post-implantation period. Histological evaluation of the optic nerve head revealed slight tissue encapsulations surrounding the electrode and increased expression of glial fibrillary acidic protein near the surface of the optic nerve.
Conclusions : Implantation of transscleral intrapapillary microelectrodes appears to be safe and effective. These findings indicate that the implantation of microelectrodes in the optic nerve head should be considered for an optic nerve-based prosthesis. Less
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