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Abstract #3448 Published in IGR 4-2
The effect of contrast and luminance on mfERG responses in a monkey model of glaucoma
Raz D; Seeliger MW; Geva AB; Percicot CL; Lambrou GN; Ofri RInvestigative Ophthalmology and Visual Science 2002; 43: 2027-2035
PURPOSE: To evaluate the effect of contrast and luminance attenuation on the multifocal electroretinogram (mfERG) responses of normal and glaucomatous eyes of cynomolgus monkeys. METHODS: Nine adult male cynomolgus monkeys with unilateral experimentally induced glaucoma were used. Hypertension-induced damage was confirmed by tomography of the optic disc. mfERGs were recorded with five different stimulus contrasts and/or luminance settings. The first-order and the first slice of second-order responses were analyzed. RESULTS: Waveforms of normal and glaucomatous eyes differed in shape and amplitude. Second-order responses contributed to first-order responses of the signals in the normal eyes, but made a negligible contribution to the signals in the glaucomatous eyes. Contrast and luminance attenuation affected both first- and second-order responses. The differences between signals in normal and glaucomatous eyes were sufficiently large for an unsupervised clustering algorithm to achieve accurate segregation. CONCLUSIONS: The observations in this study indicate that outer and inner retinal generators participate in first-order mfERG responses and that both inner and outer retinal contributors respond to contrast and luminance changes in stimulus. The hypertension-induced changes in the mfERG furthermore suggest damage to both inner and outer retina.
Dr. D. Raz, Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel. razdo@agri.huji.ac.il
Classification:
5 Experimental glaucoma; animal models
6.7 Electro-ophthalmodiagnosis (Part of: 6 Clinical examination methods)
