Parasympathetic denervation hypersensitivity of the iris in ocular hypertension

Seventy-eight ocular hypertensive patients and 47 age-and sex-matched control subjects were assessed for parasympathetic denervation hypersensitivity of the iris using topical application of 2.5% methacholine chloride solution. Constriction of the pupil in response to methacholine stimulation of the sphincter pupillae was significantly greater in the ocular hypertensive patients than the control group (P less than 0.001). The implications are discussed, with particular reference to the association between autonomic neuropathy and the primary glaucomas.