advertisement
Abstract #10396 Published in IGR 6-1
PRBS-determined temporal frequency characteristics of VEP in glaucoma
Momose K; Kiyosawa M; Nemoto N; Mori H; Mochizuki M; Yu JJDocumenta Ophthalmologica 2004; 108: 41-46
The purpose of this study was to determine whether the PRBS-VEP-determined temporal frequency characteristics (TFCs) of the visual pathways are useful for evaluating the properties of the visual system of glaucomatous patients. VEPs elicited by pseudorandom stimulation (PRBS) with red LEDs were recorded from 26 eyes with primary open angle glaucoma and 11 age-matched normal eyes. The glaucomatous patients were divided into three groups according to the size and shape of their visual field defect; early (nine), moderate (nine), and severe (eight). The cross-spectrum between PRBS and PRBS-VEPs was used as TFCs. TFCs of each glaucomatous group were compared to those of the normal controls. Depression of TFC was found for the middle and high frequencies (18-28 Hz) in the moderate group, and the depression spread to lower frequencies (4-16 Hz) in the severe groups. TFC values at 14-20 Hz were depressed in the moderate group and most frequencies were depressed significantly with the progression of glaucoma (p < 0.05). The sensitivity of the TFC at 18-20 Hz was 56, 89 and 100% in the early, moderate and severe glaucoma groups, respectively, and the specificity was 82%. The authors conclude that PRBS-determined TFC is altered in glaucomatous eyes, and the frequencies depressed were related to the degree of glaucoma. These findings indicate that PRBS-determined TFC can be useful for evaluating visual function of glaucomatous eyes.
Dr. K. Momose, Department of Information Network Engineering, Kanagawa Institute of Technology, Atsugi, Japan. momose@nw.kanagawa-it.ac.jp
Classification:
6.7 Electro-ophthalmodiagnosis (Part of: 6 Clinical examination methods)