• mydriasis;
  • phacoemulsification;
  • phenylephrine;
  • tropicamide


Purpose: To compare the mydriatic effect and safety between different concentrations of tropicamide and phenyle­phrine in preoperative mydriasis for phaco­emulsification.

Methods: Two hundred and seventeen consecutive eyes in the same number of Chinese patients undergoing phaco­emulsification under local or topical anaesthesia in a university-based eye hospital were analyzed. Patients were randomized into two groups by cluster randomization, each group receiving a different preoperative mydriatic regimen. Regimen A consisted of tropicamide 1.0% with phenylephrine 2.5%, and Regimen B consisted of tropicamide 0.5% with phenylephrine 0.5%. The main outcome measures were horizontal pupillary diameter, systolic, diastolic and pulse pressure and pulse rate.

Results: The group who received Regimen A attained a mean horizontal pupillary diameter of 7.00 ± 1.06 mm. Their pupils were significantly larger than those receiving Regimen B (6.61 ± 1.03 mm, P = 0.007). No untoward cardiovascular effects were noted in either groups.

Conclusion: Regimen A attained better preoperative mydriasis for phacoemulsification than Regimen B. Both regimens were safe with regard to their cardiovascular effects. The combination of tropicamide 1.0% and phenylephrine 2.5% is recommended as preoperative mydriatic for phacoemulsification in Chinese patients who have darkly pigmented irides.