Comparison of the mydriatic effects of mydrin-P and compound tropicamide in the screening of retinopathy of prematurity.

Purpose: To observe and compare the effects of pupil dilation between Mydrin-P and compound tropicamide in the screening of retinopathy of prematurity.

Methods: The right eyes of premature infants received My- drin-P eye drops as the treatment group, whereas the left eyes were administered with compound tropicamide as the control group. The eye drops were delivered every 5 min for three times. The pupil size was observed and recorded at 10, 15, and 20 min after administering mydriasis.

Results: The mean pupil diameter did not significantly differ between the treatment and control groups at 10 (6.24 ± 0.72 mm vs. 6.24 ± 0.68 mm, t = 0.00, P = 1.00), 15 (6.83 ± 0.55 mm vs. 6.78 ± 0.54 mm, t = 1.75, P = 0.083) or 20 min (7.22 ± 0.40 mm vs. 7.15 ± 0.50 mm, t = 1.62, P = 0.109), respectively. How- ever, the mean pupil size at any two time points significantly differed in both groups (all P < 0.001).

Conclusion: Both Mydrin-P and compound tropicamide exert similar clinical efficacy in the screening of retinopathy of pre- maturity. The most appropriate time for screening was at 20 min after mydriasis.