1990 Fiscal Year Final Research Report Summary
Early Detection and Treatment of Glaucoma with the Aid of Optic Disc Measurements with a Computerized Image Analysis
| Project/Area Number |
62440069
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (A)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Ophthalmology
|
|---|
| Research Institution | Niigata University |
|---|
Principal Investigator |
IWATA Kazuo Niigata University, School of Medicine, Dept. of Ophthalmology, Professor, 医学部, 教授 (10018301)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
NANBA Katsuhiko Niigata University, School of Medicine, Dept. of Ophthalmology, Lecturer, 医学部・附属病院, 講師 (80018738)
|
|---|
| Project Period (FY) |
1987 – 1990
|
| Keywords | Optic disc measurement / Optic disc area / Rim area / Cup area / Cup volume / Cup depth / Cup shape / Large cup |
|---|
| Research Abstract |
Optic disc measurements with a computerized image analysis revealed that optic disc parameters (rim area, cup area, cup volume) are significantly correlated to optic disc area in normal (NL) eyes. Although statistically significant differences were observed among NL, ocular hypertensive (OH) and early glaucomatous (GL) eyes for these parameters, the 95% prediction values of rim area in NL could differentiate only 25.0% of OH and 52.9% of GL from NL. In spite of the wide distribution and large overlap of the values of the parameters among three groups, OH and GL with the optic disc equal > 053.0mm^2 showed no overlap of the values with NL. From these results, larger optic discs seem to be more vulnerable to increased IOPs. Measurements of the depth of optic disc cup showed optic disc cup in OH and GL was significantly deeper than that in NL. Thsese findings may support the idea that the deformation of the lamina cribrosa in early stage of glaucoma could cause optic disc cupping. In four cup shapes classified with a computerized image analysis, the cupーshaped cup was most frequently found in NL, the plateauーshaped cup in OH and the twoーpeakーshaped cup in GL. The optic disc cup may change from coneーshaped to plateauーshaped and twoーpeakーshaped with the progression of glaucoma. The relationship between optic disc parameters and retinal nerve fiber layer defects (NFLD) in GL revealed a significant loss of rim area in the earliest stage of NFLD. The relationship between the parameters and visual field defects indicated that a loss of 0.37mm^2 in rim area, 0.38mm^2 in cup area and 0.16mm^3 in cup volume may precede visual field defects.
|
