The Effect of Topical Anesthesia on Pharmacological Mydriasis in Diabetic Patients Depends on the Presence of Retinopathy

Purpose: Instillation of topical anesthetics with or without preservatives in normal persons has been shown to enhance the effect of mydriatic eye drops. The purpose of the present investigation was to study whether a similar effect can be observed in diabetic patients screened for retinopathy and whether the effect depends on the presence of retinopathy. Methods: Thirty-six patients attending a screening programme for diabetic retinopathy were randomized to receive local anesthetic eye drops on one eye, followed by instillation of both a sympathomimetic and a parasympatholytic eye drop in both eyes, which was repeated after 20 minutes. The pupil diameter in both eyes was measured with 5 minutes intervals until 35 minutes after the first application of mydriatics, and the responses in the two eyes were compared. Results: The pupil diameter increased significantly throughout the observarion period in both eyes (p