SIMULTANEOUS ELECTRORETINOGRAMS AND VISUALLY EVOKED-POTENTIALS FROM ADULT AMBLYOPES IN RESPONSE TO A PATTERN STIMULUS

Abstract

Electroretinograms (ERG) and visually evoked potentials (VEP) were recorded simultaneously from each eye of 3 adult [human] amblyopes. A spatially alternating checkerboard pattern stimulus of constant mean luminance was used to eliminate the effect of stray light on the ERG. The VEP was affected in the amblyopic eye of all subjects. In 2 subjects the VEP amplitude was reduced. In the 3rd subject the amplitude was not attenuated, but the waveform of the VEP was markedly altered. Photopic ERG recorded from the normal and amblyopic eye of each subject using an unpatterned flashing light were equal in amplitude. ERG elicited by a patterned stimulus were affected in the amblyopic eye of all 3 subjects; the after-potential showed larger reductions in amplitude than the b-wave. Results suggest some retinal involvement in human amblyopia.