A quasi-experimental study to assess the effect of a local anesthetic proparacaine on tropicamide-induced pupillary dilation.

ABSTRACT

Background: Dilating the pupil is one of the most commonly practiced methods among ophthalmologists to examine the eye especially the posterior segment of the eye. Here we conducted a study to know the clinical effect of proparacaine, a local anesthetic, on tropicamide-induced pupillary dilation. Methods: A Quasi-experimental study was conducted on 57 subjects aged between 20 and 70 years. Study was done over a period of 3 months (February 14 - April 14) at a tertiary health care center in Bagalkot after obtaining institutional ethical committee clearance. Proparacaine was instilled in one eye (right eye) before instilling tropicamide and the other eye with a placebo (normal saline). Pupil diameter was measured using a pupillary gauge at 0, 15, and 30 mins. Results were analyzed using unpaired Student’s t-test. Results: The mean clinically efficient pupillary diameter at the end of 15 mins in proparacaine instilled eye was 5.56±0.5 and in control eye was 5.25±0.45 mm with t value 8.13 (p<0.001) which was statistically significant. And at the end of 30 mins pupillary diameter in the study group was 7.96±0.43 mm and in the control group was 7.83±0.43 mm with t value of 4.115 (p<0.001) which was also statistically significant. Conclusions: Therefore, we do recommend the use of proparacaine before instilling tropicamide for faster pupillary dilation.