Retinal adaptation effects on the patterned VEP and ERG.
The patterned visually evoked potential (pVEP) and patterned electroretinogram (pERG) after light and dark adaptation were investigated in 10 visually normal human observers. The influence of retinal preadaptation on the pVEP appeared to be dependent on the stimulus field size. With a 6 degree field size retinal adaptation effects were not apparent, but with a 12 degree field size the amplitudes of the dark-adapted steady-state pVEP (ssVEP) and transient pVEP (tVEP) were significantly larger than the light-adapted amplitudes. Similarly pERG's elicited by a 12 degree field size produced larger amplitude dark-adapted results. The implications of these findings are discussed. Monitoring the temporal changes in the pVEP subsequent to different retinal preadaptation levels proved to be inconclusive for the conditions studied.
School of Optometry, University of Waterloo, Ontario, Canada.
M M
MM
Spafford
S L
SL
Lu
D000221:Adaptation, Ocular; D000328:Adult; D003623:Dark Adaptation; D004596:Electroretinography; D005074:Evoked Potentials, Visual; D006801:Humans; D012160:Retina / Q000502:physiology*; D013997:Time Factors; D014787:Vision Tests