The Pupillary Dilatation Effect of Phenylephrine 2.5% Versus 10% in Patients with Diabetes

ABSTRACT

We assessed the degree of mydriasis induced by 1% tropicamide and 2.5% phenylephrine compared with that induced by 1% tropicamide and 10% phenylephrine in 100 patients with diabetes. Additionally we studied the difference of pupillary dilatation according to duration of dibetes, severity of retinopathy, and performance of photocoagulation. Maximum dilated pupillary diameter was 7.25+/-1.27mm in 2.5% phenylephrine group and 7.32+/-1.36mm in 10% phenylephrine group, respectively the difference in pupillary dilatation between two groups was not statistically significant. We advise the use of the 2.5% phenylephrine in patients with diabetes, who already exhibit a higher prevalence of vascular disease and autonomic nerve system dysfunction because 2.5% phenylephrine may produce a lower incidence of side effects than 10% concentration and have the same effect of pupil dilatation as 10% phenylephrine.