An improved electrode for electroretinography: design and standardization.

An electrode for electroretinography was developed that fits over the patient's lower lid. The electrode incorporates a platinum strip embedded in a piece of shaped plexiglass. The electrode was standardized for clinical use by comparing ERG recordings from this platinum lid electrode with those recorded from a Burian-Allen electrode. The a- and b-wave implicit times and amplitudes were measured in four subjects, using both electrodes under varying luminance conditions, to provide a measure of the validity of the platinum lid electrode. The same experimental procedure was repeated five times on two individuals to provide a measure of the reliability of both electrodes. Results indicate amplitudes approximately 65% of those recorded with a Burian-Allen electrode but which are otherwise in good agreement.