[The problem of the impairment of the action of parasympatholytic substances. Ophthalmologic criteria and methods].

UNLABELLED

The parasympatholytic effects on the eye were investigated in 12 healthy volunteers. In a randomized cross-over double-blind trial 20 or 40 mg N-butylscopolaminium bromide (Buscopan) or placebo was given by i.v. injection. Pupillary light reaction, range of accommodation, visual acuity, and nyctometer values were measured up to 45 min after injection.

RESULTS

1. The mydriatic effect of both dosages of the drug is moderate. Pupil diameters at the end of the light reaction are only slightly greater under the influence of the drug than in control experiments. The dynamics of the reaction remains unaltered. 2. The range of accommodation diminishes in a dose-dependent manner. 9-15 min after the injection the inhibition is maximum. 45 min after injection, even of the 40 mg dosage, only a small effect remains. 3. Visual acuity and nyctometer values are not affected by N-butylscopolaminium bromide. The findings were discussed with respect to the ability to meet the requirements of road traffic.