Electrophysiology in pigment epithelial changes

Abstract
The c‐wave of the ERG and the slow SP variations reflect mainly the activity of the pigment epithelium. However, both potentials are dependant upon the photoreceptors and/or the inner retina as well. In pigment epithelial abnormalities the c‐wave is reduced or abolished, and the slow SP variations, d.c. recorded directly or investigated with the EOG, reduced or abolished as well.