Electroretinography by skin electrodes and signal averaging method.

In the investigation of suspected visual disorders, ERG is of considerable value. A simplified method for clinical electroretinography by non-corneal electrodes is presented. The latency and amplitude values were measured in 22 normal subjects. Using skin electrodes and signal averaging, we can record, without discomfort to the patient, an electroretinogram with a waveform and time relations similar to those obtained by corneal electrodes. Non-corneal ERG is useful for infants, children as well as sensitive adult patients, and is also applicable after recent eye surgery and in cases of infection or injury of the anterior segment. Since non-corneal electrodes do not obstruct the stimulus light or cause of refractive change, they are advantageous when ERG is recorded simultaneously with visually evoked cortical response (VER). When it is important to stimulate only one eye at a time in flash VER, the adequacy of the cover is verified by the absence of an ERG from the covered eye.