Parasympathetic denervation of the iris in alcoholics with vagal neuropathy.

Parasympathetic innervation of the pupil was studied in 30 alcoholics. Twelve alcoholics had cardiac vagal neuropathy. The resting pupillary diameters in this group were larger, and pupil responses to methacholine were greater, than in control subjects or alcoholics without vagal neuropathy. These observations imply that lesions in the parasympathetic supply to the pupil may occur in alcoholics with other evidence of autonomic neuropathy involving the parasympathetic system.