1996 Fiscal Year Final Research Report Summary
MOLECULAR BIOLOGIC STUDY ON CORTICOSTEROID-INDUCED GLAUCOMA
| Project/Area Number |
07671925
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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 | WAKAYAMA MEDICAL COLLEGE (1996)
Kyushu University (1995) |
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Principal Investigator |
TAWARA Akihiko WAKAYAMA MEDICAL COLLEGE,A SSOCIATE PROFESSOR, 眼科学教室, 助教授 (90117169)
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| Project Period (FY) |
1995 – 1996
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| Keywords | corticosteroid-induced glaucoma / triamcinolone acetonide / histochemistry / extracellular matrix / Proteoglycans / exfoliation syndrome / goniodysgenetic glaucoma / neovascular glaucoma |
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| Research Abstract |
We performed subtenon injection of 20 or 40 mg triamcinolone acetonide into right eyes of Japanese rabbits, and measured their intraocular pressures periodically for 4 weeks. The anterior chamber angle tissues obtained from the animals were examined histologically and histochemically using alcian blue or cupromeronic Blue. There was no significant increase of the intraocular pressure compared to control left eyes. No histological or histochemical change was detected in the trabecular tissues from corticosteroid injected eyes. The results suggest that there may be some difference in reactivity to corticosteroid between human and rabbit eyes.
The effects of anterior segment ischemia on angiogenesis in the anterior segment of the eye were investigated. We cauterized both of the long posterior ciliary arteries in the right eye of 14 rabbits. The eyes were enucleated 1,2,4,7,9 and 14 days after cauterization and were studied with light microscopy. The localization of vascular endothelial gro
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wth factor (VEGF) protein and the expression of VEGF mRNA in the tissues were studied. Neovascularization on the anterior surface of the iris and in the trabecular meshwork was detected. No histological changes were observed in the retina. VEGF protein was detected in the epithelial and vascular cells of the iris. Expression of VEGF mRNA was detected in the epithelial cells of the ciliary body. These results suggest that anterior segment ischemia causes neovascularization in the anterior segment of the eye.
The trabecular tissues from 4 enucleated human eyes with exfoliation syndrome were examined histologically and immunohistochemically. Exfoliation fibers were revealed to contain chondroitin sulfate dermatan sulfate and heparan sulfate-type proteoglycans as well as HNK-I epitope, while microfibrils in the extracellular matrix did not. The results suggest that depositions of proteoglycans and other macromolecules on the microfibrils may be closely associated with the formation of exfoliation materials.
We examined morphologically the ratio of the ciliary body band width to the width of the posterior limbus, termed the theoretical C/L ratio, of enucleated human eyes, including those from premature infants as well as from older subjects. We also examined clinically the appearance of the ciliary body band on gonioscopy in patients having glaucoma with open iridocorneal angles, and in age mathched controls. The theoretical C/L ratio was 1.4(]SY.+-。[)2.7% in premature infants, 24.0(]SY.+-。[)5.4% in children and 36.7(]SY.+-。[)8.0% in the older subjects. On gonioscopy, 77.8% glaucomatous eyes and 13.8% control eyes showed either an invisible or very narrow ciliary body band. The results indicate that an invisible or very narrow ciliary body band represents an nuderdevelopment of the angle. Less
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