To evaluate and compare the efficacy of two concentrations of Tropicamide eye drops to dilate pupils in patients on routine ophthalmologic examination.

: In this study, 25 patients who were referred just for routine examinations were enrolled. The patients with history of ocular surgery and also patients with cataract, glaucoma and retinal problems excluded from the study. Tropicamide eye drop at a concentration of 0.5% and 1% were applied in the right and left eye respectively. The Pupil size was measured by the Topcon Slit Lamp Imaging System before applying of the eye drop, then 5 minutes, 20 minutes and 60 minutes after applying of the Tropicamide eye drops.

the mean age of patients was 46.4 + 11.8 years. Pupil diameter before Tropicamide instillation was 3.5+ 0.78 mm in right eye and 3.48+ 0.69 mm in left eye. Pupil diameter 5 minutes after applied Tropicamide eye drop in right eye was 4.45 + 0.93mm and in left eye was 4.45±0.93. Mean pupil diameter 20 minutes after applied Tropicamide eye drop was 6.88 + 0.464 mm in right eye and was 6.93 + 0.627 mm in left eye. Between the two groups, the mean difference in pupil diameter after 5 min, 20 min and 60 min after applying of eye drops Tropicamide, was not statistically significant.

According to the results of this study, the effect of tropicamide on pupil dilating, at a dose of 0.5% is acceptable, Thus, using lower doses of Tropicamide eye drops to avoid side effects is recommended.