2004 Fiscal Year Final Research Report Summary
Development of Methods for Evaluating Function and Pathophysiology of Visual System (optic nerve to visual cortex).
| Project/Area Number |
14571660
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | Niigata University |
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Principal Investigator |
TAKAGI Mineo Niigata University, Medical and Dental Hospital, Lecturer, 医歯学総合病院, 講師 (60251807)
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| Project Period (FY) |
2002 – 2004
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| Keywords | Visual System / Neuro-Ophthalmological Disease / Vergence Eye Movement / MRI / Stereopsis / Eye Movement Control System / Optic Nerve |
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| Research Abstract |
We applied newly developed methods to evaluate visual and eye movement functions and was able to acquire data from normal subjects and patients with neuro-ophthalmological disease.
1)Using wide three-dimensional visual stimulator and eye movement recording systems, we revealed that the background behind the disparity target had strong effect on convergence amplitude, that peripheral disparity target had strong effect on the initial open-loop part of the convergence response, and that the latency of saccade-type vergence movement was greater than that of pursuit-type vergence movement. From these facts, we discussed neuronal mechanism of three-dimensional visual analysis.
2)Using diffusion-weighted magnetic resonance imaging(MRI) which detect apparent water diffusion, we evaluated axonal diffusivity of the optic nerve. In patients with acute optic neuritis, diffusion in the optic nerve measured optic canal portion was smaller, while in those with chronic optic atrophy it was greater. These results seem to be very useful for differential diagnosis of optic nerve diseases.
Experiment for other parts of visual pathway, such as optic chiasm and optic tract, is now on going.
3)Functional MRI using BOLD method to detect regional blood flow increase in the brain, it was revealed that lobuli VII of the cerebellar vermis is related to both saccadic and pursuit eye movements. Considered with literatures, it was suggested that this part is also related to vergence eye movement control.
Recently, neuron which code both version and vergence eye movements has been discovered. We disc ussed theoretically how three dimensional visual information and vergence eye movement, which have once been considered to be independent subsystem, are controlled in the central nervous system.
These data, we believe, could contribute to neuro-ophthalmology clinic directly.
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