ERG and VECPs in retinal detachments.

In retinal detachments the scotopic ERG is generally more disturbed than the photopic ERG; both are more disturbed than would be expected from the visible detached retina. The disturbance is characterized by a reduction of both the a-wave and the b-wave. Furthermore, the photopic responses are clearly delayed when the detachment extends over more than half of the retina, giving a typical, even pathognomonic, wave form when the detachment covers more than three quarters of the retina. Even in total detachments, such a response, though very small, can usually be obtained, as well as a VECP after strong light flashes. Most likely they are responses of the detached retina.