Psychophysical and electrophysiological testing of retinal function. Macular recovery time and oscillatory potentials in normal subjects.

Abstract

We evaluated different aspects of 1) psychophysical and 2) electrophysiological testing procedures of retinal function, represented by macular recovery time (nyctometry) and oscillatory potentials (electroretinography), respectively. Ninety healthy males, aged 18-28 years, were used in the study. We registered two different phases of macular recovery time, IRT: initial recovery time (less than 40 sec) and AUC: area under the curve (less than 120 sec) and both individual and summed nodes of oscillatory potentials (OPs). A significant effect of training was observed in monocular registration of IRT and AUC (P less than 0.01), and the superiority of binocular recovery was numerically compared to monocular recovery (P less than 0.01). The inter-variability (coefficient of variation) of IRT was high (40%) in both monocular and binocular registrations, while AUC had a smaller variability binocularily than monocularily (33% vs 21%). The inter-variability of OPs was low (16%). Intra-variability, between first and second eye tested, showed highly correlated values in IRT, AUC and OPs (r = 0.51-0.82; P less than 0.004), while IRT/AUC was not correlated to amplitudes of OPs. The results emphasize that selecting one eye, mean of two eyes or both eyes are critical for accuracy and validity in psychophysical testing of visual performance.