Macular function in eyes with early age-related macular degeneration with or without contralateral late age-related macular degeneration.

PURPOSE

To evaluate psychophysical and electrophysiologic responses in eyes with early age-related macular degeneration (AMD) without a decrease in visual acuity and with or without late AMD in the fellow eye.

METHODS

Fifteen patients (mean age: 67.9 +/- 7.20 years) with early AMD in both eyes (AMD1 group, 15 eyes) and 15 patients (mean age: 71.40 +/- 7.06 years) with early AMD in one eye and late AMD in the fellow eye (AMD2 group, 15 eyes) were enrolled. They were compared to 15 age-similar normal control subjects. LogMAR visual acuity (VA), macular sensitivity by MP-1 microperimetry, and multifocal electroretinograms (mfERG) were assessed in control, AMD1, and AMD2 eyes. mfERG response amplitude density (RAD, nV/deg2) of the N1-P1 component of first order binary kernels was measured.

RESULTS

When compared to controls, AMD1 and AMD2 eyes showed a significant (analysis of variance, P < 0.01) decrease in MP-1 microperimetry assessed in the 0-2.5 and 2.5-5 degrees of the macula, significantly correlated (Pearson test, P < 0.01) to the corresponding significant decrease (P < 0.01) in mfERG N1-P1 RADs assessed in the 0-2.5 and 2.5-5 degrees. In AMD1 and AMD2 eyes, VA and mfERG N1-P1 RADs assessed in the 5-20 degrees were similar (P > 0.01) to controls. VA, MP-1, and mfERG values were not significantly different in AMD1 and AMD2 eyes.

CONCLUSION

In eyes with early AMD there is a dysfunction of preganglionic elements in the central 0-5 retinal degrees detectable by mfERG or MP-1 microperimetry. This impairment is not further influenced by the presence of late AMD in the fellow eye.