Absence of parasympathetic denervation of the iris in alcoholics

S U M MARY Forty patients with a history of alcohol abuse were treated with a 2 % solution of methacholine to determine the prevalence of iridic parasympathetic denervation. Three (8%) of the alcoholics showed iris constriction of 10 mm or more, compared with three (8%) control subjects. In contrast, damage to the iridic parasympathetic nerve supply occurs in approximately 80 % of patients with diabetes mellitus as determined by the same pharmacological technique. Peripheral neuropathy is a well-known complica-tion of chronic excessive ethanol consumption associated with dietary deficiency. However, symptomatic involvement of the autonomic nervous system is unusual in alcoholics. Novak and Victor (1974) have reported three severely ill patients with dysphonia and dysphagia who at necropsy showed degeneration of the vagus nerves. Excessive or absent sweating of the feet may also be seen in alcoholics with polyneuropathy. In diabetes mellitus, somatic neuropathy may occur early and may even be present before other manifestations of disordered carbohydrate metab-olism. Involvement of the autonomic nervous system has also been shown to occur early in the course of the disease (Martin, 1953). Para-sympathetic denervation hypersensitivity of the iris to 2 % methacholine was found in 74 % of diabetics diagnosed within the preceding two years (Sigsbee et al., 1974). The sensitivity of the metha-choline test in showing early parasympathetic denervation of the iris in diabetes mellitus led us to study alcoholics to determine the prevalence of iridic denervation in that population. Subjects and methods Forty male alcoholic patients in the White Rive