EFFECT OF RETINAL DEGENERATION ON FLASH AND PATTERN VISUAL-EVOKED RESPONSES

A retrospective study was undertaken of the flash and pattern visual e voked responses (VER) from 43 patients who were diagnosed with retinal degenerations. The patients were divided into a macular dystrophy gro up and a rod-cone degeneration group. Flash and pattern VER P-1 implic it times were analyzed for each group. The results revealed that the p attern VER P-1 implicit time was significantly more delayed in the mac ular dystrophy group than in the rod-cone degeneration group. Converse ly, flash VER P-1 implicit time was in general more delayed in the rod -cone degeneration group than in the macular dystrophy group. Differen ces in P-1 implicit times between flash and pattern VERs within each g roup also suggested that the pattern VER was more delayed than the fla sh VER in the macular degeneration group and that the flash VER was mo re delayed than the pattern VER in the rod-cone degeneration group. Th e results are explained by the effective area of the flash and pattern VER stimuli and the relative retinal locus of each general type of re tinal degeneration.