1996 Fiscal Year Final Research Report Summary
Development of an istrument evaluating re tinal circulation in vivo.
| Project/Area Number |
06557090
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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 | 試験 |
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| Research Field |
Ophthalmology
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| Research Institution | University of Tokyo |
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Principal Investigator |
ARAIE Makoto Univ Tokyo, Dept opththalm of. Ass Prof., 医学部・附属病院(分), 助教授 (00092122)
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| Co-Investigator(Kenkyū-buntansha) |
FUJII Hitoshi Kyushu Technological College. Prof., 情報工学部, 教授 (70133775)
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| Project Period (FY) |
1994 – 1996
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| Keywords | Retina / Argon laser / laser speckle / Blood velocity / Ca^<2+> antagonist / retinal vein |
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| Research Abstract |
A fundus camera was installed with argon blue laser which was projected onto the ocular fundus where laser speckle patter appears. Speckle pattern was imaged onto an image sensor (100*100 pixels) from which normalized blur value (NB) was calculated as a quantitative index of tissue blood velocity. In rabbit experiments, NB obtained from the retina showed a good and significant correlation with the blood flow rate determined by the microsphere method in the same eye, when stepwise increase in the intraocular pressure was induced. These results indicated that NB value reflects the cirdulation status of the retina and non-contact and noninvasive measurement of retinal hemodynamics is possible in living eyes using the apparatus constructed. Further, the apparatus was improved so that it can measure the blood velocity in large retinal veins and the blood velocity in the large retinal veins in humans was found to average 1.5-2.0 cm/sec, which agreed well with the value obtained by other methods.
Using the apparatus constructed, effect of systemic calcium antagonists on retinal peripheral circulation was evaluated. Nilvadipine, pranidipine, semothiazil and nicardipine were found to increase the retinal tissue blood velocity, but the effect of semothiazil appeared to be most prominent. Further, increase in the retinal blood flow rate determined with the microsphere method after oral semothiazil agreed well with increase in the NB value after oral semothiazil, which further warrants the validity of the laser speckle methodology. The present study demonstrated the usefulness of the apparatus constructed here and possibility that oral calcium antagonist can by used in retinal disorders associated with reduced blood flow.
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