Abstract
Purpose: :
To evaluate the efficacy of a single drop versus a 3–drop regime using 1% tropicamide for mydriasis in patients with darkly pigmented irides.
Methods: :
A prospective randomized, single masked clinical trial involving 30 patients (60 eyes) with darkly pigmented irides. One eye of each patient was randomly assigned to receive a single drop of 1% tropicamide (Regime A) while the other eye received one drop of 1% tropicamide thrice at 5–minute intervals (Regime B). A masked observer measured the pupil size in both eyes at 5–minute intervals for 45 minutes using a reference pupil chart.
Results: :
The median age of the participants was 53 years (range, 20 – 80) with 47% males and 53% females. The ethnic distribution was 53% Chinese, 27% Indian and 20% Malay. Six patients were diabetic. The pupil size at 45 minutes (PS–45) and the rate of mydriasis (RM in mm/min) were not significantly different between the 2 regimes (p = 0.081 and p = 0.056 respectively). The efficacy of the regimes, in terms of PS–45 and RM, was not affected by ethnicity (p = 0.091 and p = 0.434 respectively), the presence of diabetes mellitus (p = 0.312 and p = 0.219 respectively) or age (p = 0.211 and p = 0.263 respectively).
Conclusions: :
A single–drop of 1% tropicamide is as efficacious as a 3–drop regime in dilating pupils of darkly pigmented irides. The efficacy of the regimes is not influenced by ethnicity, the presence of diabetes mellitus or age.
Keywords: pupil • iris • drug toxicity/drug effects