(Multifocal) ERG : additional functional information in research and clinical settings

Abstract

Abstract Purpose: To investigate the relationship between areas of hyper‐ and hypofluorescence and measures of visual function in patients with macular diseases. Methods: Eight patients (8 eyes) with macular disease aged from 26‐80 yrs. were enrolled in the study. All tested eyes had best corrected visual acuities of at least 20/100 and areas of abnormal fundus autofluorescence (FAF) in the posterior pole. Retinal function was evaluated with the multifocal ERG (mfERG) VERIS system using a display of 61 hexagons. Fixation was continuously monitored. First order kernel responses were analyzed. Results: The pattern of hyperfluorescence varied with the macular findings as well as the stage of disease. For all patients, MP‐1 and HVF fields showed decreased sensitivity in locations corresponding to and adjacent to hypofluorescent (atrophic) areas. Multifocal ERG response amplitudes were decreased and sometimes delayed in the same regions. Deficits extended into areas of normal FAF. Hyperfluorescent areas adjacent to normal appearing areas had normal visual function, whereas those adjacent to atrophic areas had decreased visual function. In patients with ABCA4 related maculopathy, flecks adjacent to normal FAF had normal visual function with the MP‐1. In contrast, flecks adjacent to atrophic areas had reduced visual sensitivity. Two patients with ABCA4 dystrophies had eccentric PRLs in superior retina. Conclusions: The correlation of fundus hyperfluorescence with cone system function is related to the health of adjacent retinal pigment epithelium. There is a need to use functional techniques as well as FAF in monitoring macular disease progression.