Revealing a retinal facilitatory effect with the multifocal ERG

Purpose We have previously shown that the amplitude of the mfERG response obtained to a single (large) hexagon is significantly smaller than that obtained when summating all the mfERG responses evoked to an array of 7–61 hexagons covering the same retinal area. The purpose of this study was to confirm our initial findings in normal subjects of different ages and in selected patients.