INCREASE IN CONE-ELECTRORETINOGRAM B-WAVE DURING LIGHT ADAPTATION

Background In experimental and in clinical electrophysiology, cone electroretinograms (ERG) undergo typical changes of the b-wave during the course of light adaptation. Methods and results B-Waves obtained from twenty healthy subjects, exposed to a rod-desensitizing adapting field for ten minutes show an increase of amplitude. This increase was observed using a short wavelength as well as with a long wavelength stimulus. The cone ERG implicit times decrease slightly during light adaptation. Conclusions To avoid considerable variation in clinical cone-ERG it is necessary to wait a certain period of time before measuring cone b-waves and comparing them with normative values. Possible mechanisms underlying these adaption-induced ERG changes are discussed.