Sixty-two patients suffering from degenerative changes in the macular region were examined electroretinographically (ERG). Most of the heredomacular dystrophies showed severe subnormality of the photopic components of the ERG and less severe subnormality of the scotopic components. This indicates that the disease affects the retina as a whole, though ophthalmoscopically it often appears localized in the macula. Macular degenerations secondary to inflammatory processes showed an ERG of normal amplitude and recovery. The senile macular degenerations, including the disciform type, displayed subnormal retinal responses, but normal recovery of all components was similar to the ERG often recorded in old people without these degenerations. Color vision was defective in 48 of the 62 cases, achromatopsia being slightly more frequent than protanomaly or deuteranomaly. All patients with achromatopsia displayed "scotopic line" in the Farnsworth panel D-15 test.
Merin S, Auerbach E. The Central and Peripheral Retina in Macular DegenerationsInvolvement as Reflected by the Electroretinogram. Arch Ophthalmol. 1970;84(6):710-718. doi:10.1001/archopht.1970.00990040712002