| Project/Area Number |
06671761
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Ophthalmology
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| Research Institution | Osaka University |
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Principal Investigator |
FUJIKADO Takashi Medical School, Assistant Professor., 医学部, 助手 (50243233)
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| Co-Investigator(Kenkyū-buntansha) |
OHJI Masato Medical School, Assistant Professor., 医学部, 助手 (90252650)
TANO Yasuo Medical School, Professor., 医学部, 教授 (80093433)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | MYOPIA / FORM DEPRIVATION / GLUTANATE / ERG / RETINAL CIRCUIT / CHICK / 凹レンズ / ON反応 / OFF反応 |
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| Research Abstract |
(1) Intravitreal administration of kainic acid (KA), a glutamate agonist acting on AMPA/KA receptor, induce myopia with axial elongation in developing chicks, while 2-amino-phosphonobutyrate (APB), acting on metabotropic receptor, induce hyperopia with axial shortening. Both ON responses and OFF responses of ERG were reduced in eyes with KA injection, while only ON responses were specifically reduced in eyes with APB injection, suggesting that myopic change is related to the retinal circuits concerning ON and OFF responses.
(2) Pattern ERG (RERG) showed reduction of amplitudes in the stimuli of the middle to high spatial frequency in eyes with KA injection, while all frequency range in eyes with APB injection, suggesting that not general reduction of retinal information processing but rather selective impairment of retinal circuits concerning the middle to high spatial frequency.
(3) Chicks grown with negative lenses showed myopic change with axial elongation in relation to the power of lenses they wore. Amplitude of oscillatory potentials in eyes worn negative lenses were reduced less than that in occluded eyes, suggesting that retinal mechanism underlying axial elongation is different between lens induced and occlusion myopia.
(4) Axial length of patients with corneal scar was compared between a group of early onset and that of late onset. Axial length of early onset group was significantly longer than that of late onset group, suggesting that form deprivation during childhood leads to myopia even in clinical cases.
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