Ocular autonomic nerve function in proliferative diabetic retinopathy

Abstract

Ocular autonomic nerve function was assessed in 28 diabetic patients with proliferative retinopathy (PDR) and 61 age- and sex-matched control subjects, by measurement of the pupil cycle time and determination of autonomic denervation hypersensitivity of the iris. Sustained pupil cycle time was absent in 88.5 per cent of PDR compared with 9.8 per cent of control subjects (p<0.001). Pupil constriction in response to 2.5 per cent methacholine—indicative of parasympathetic denervation hypersensitivity—was significantly increased in PDR (p<0.001), whilst pupil dilation in response to 0.5 per cent phenylephrine—indicative of sympathetic denervation hypersensitivity—was also significantly higher in PDR (p<0.001). Pupil reflexes were abnormal in 88.5 per cent of diabetics with proliferative retinopathy, with established autonomic denervation hypersensitivity in 57 per cent of patients.