Identifying inner retinal contributions to the human multifocal ERG

Contributions to the multifocal electroretinogram (ERG) from the inner reti na (i.e. ganglion and amacrine cells) were identified by recording from mon keys before and after intravitreal injections of n-methyl DL aspartate (NMD LA) and/or tetrodotoxin (TTX). Components similar in waveform to those remo ved by the drugs were identified in the human multifocal ERG if the stimulu s contrast was set at 50% rather than the typically employed 100% contrast. These components were found to be missing or diminished in the records fro m some patients with glaucoma and diabetes, diseases which affect the inner retina. (C) 1999 Elsevier Science Ltd. All rights reserved.