Focal macular electroretinograms in eyes with wet-type age-related macular degeneration

Abstract

PURPOSE. To study the properties of the focal macular electroretinograms (fmERGs) in eyes with untreated wet-type agerelated macular degeneration (AMD). METHODS. fmERGs were recorded from 157 eyes of 157 consecutive patients with untreated wet-type AMD (113 men, 44 women; age, 71.3 ± 8.0 years). The fmERGs were recorded under direct fundus observation using a modified infrared fundus camera and a 15° stimulus spot. Amplitudes and implicit times of the fmERGs recorded from the AMD patients were compared with those from 21 age-similar healthy controls. RESULTS. The amplitudes of fmERGs in the AMD patients were significantly smaller (P < 0.001) and the implicit times were significantly longer (P< 0.001) than the corresponding values in the control eyes. There was a significant correlation between amplitude and implicit time of the fmERG and visual acuity (logMAR), but the degree of correlation was weak. The difference in the b/a amplitude ratio between the AMD patients and healthy controls was not significant. CONCLUSIONS. The significant reduction in amplitude and the severe delay in implicit times of a- and b-waves of the fmERGs indicated significant functional alterations in the inner and the outer retinal layers of the macular area of eyes with wet-type AMD. Copyright © Association for Research in Vision and Ophthalmology.