Effects of two anticholinergic drugs on electroretinograms and visual evoked potentials in healthy human subjects.

A battery of electroretinograms (ERGs) and visual evoked potentials (VEPs) were recorded from 12 normal, male volunteers after the intravenous administration of either biperiden 2.5 mg, atropine 1.5 mg or placebo, at weekly intervals. Self-reports indicated that both drugs caused significantly reduced levels of alertness compared to placebo, but more so with biperiden than atropine. Biperiden was not, however, associated with significant changes to ERGs, while atropine caused a few isolated, significant increases to implicit times. There were no significant treatment effects on pattern ERGs or VEPs. The flash VEP latencies and amplitudes recorded after the anticholinergics did not differ from placebo. These preliminary findings suggest that these anticholinergics do not have marked effects on either ERGs or VEPs.