Absence of ganglion cell subcomponents in multifocal luminance electroretinograms.

Multifocal flash electroretinograms (ERG) were recorded binocularly (n = 18). Areas were equal or scaled with excentricity. The latter were expected to increase the total amplitude if ganglion cell subcomponents were involved. Amplitudes were intercorrelated and the factor structure was established. Scaling had no influence on amplitudes or on factors. Reliability and sensitivity were high. The second kernel first slice from the nine hexagons across the midline showed differences near the macula but no component increasing in latency with distance from the disc. Thus, multifocal flash ERG have linear spatial summation and no ganglion cell subcomponents.