The focal electroretinogram in fellow eyes of patients with idiopathic macular holes
D. G. Birch, B. F. Jost and G. E. Fish
Retina Foundation of the Southwest, Dallas, TX 75231.
In a prospective study of macular hole formation, focal electroretinograms
(ERGs) were obtained from both eyes of 35 patients with a unilateral,
idiopathic, full-thickness macular hole. Foveal cone ERG amplitude was
significantly correlated with hole diameter at the initial visit.
Twenty-six patients had normal foveal cone ERGs in the fellow eye at the
baseline visit and for the duration of the study (mean follow-up, 35
months; range, 24 to 56 months). None of these eyes developed a macular
hole. Seven eyes had significantly reduced foveal cone ERGs in the fellow
eye, despite good visual acuity and a normal-appearing macula on the
initial visit. Four of these eyes subsequently developed a full-thickness
macular hole during follow-up (mean follow-up, 35 months; range, 25 to 46
months). Foveal ERG amplitude was significantly related to subsequent
macular hole formation, suggesting that this test can provide an objective
measure of macular function to help identify eyes at risk for macular hole
formation.
