Effect of Topical Proparacaine 0.5% on Tropicamide- Induced Mydriasis

Abstract

Purpose: The topical anesthetic proparacaine (0.5%) is recommended to enhance the rate and magnitude of pupillary dilatation if it is instilled before mydriatic tropicamide. However there is scarcity of data supporting this. Therefore we conducted a study to analyze if preinstillation of topical proparacaine (0.5%) can potentiate the mydriatic efficacy of 0.8% tropicamide. Methods: The patients were divided into two groups for pupillary dilatation. The study group was given a drop 0.5% proparacaine before instilling one drop of tropicamide while the control group was given the tropicamide alone. The pupillary size was measured and recorded before the instillation of tropicamide at 0 min, 15 min, 30 min. The end point was taken as 6 mm pupillary size (clinically effective diameter). Results: There was a statistically significant difference in rate of pupillary diameter between the control and the study group. The rate of pupillary dilatation at 15min and 30 min was statistically significantly different between the control and study group. Conclusion: The study concluded that prior instillation of topical proparacaine produced a statistically significant difference in the rate of pupillary dilatation at 30 mins. Therefore, we suggest the use of a topical anesthetic before tropicamide induced mydriasis.