Materials and Methods: Thirty-two healthy adults aged between 19 and 51 years were included in the current study. Both eye measurements were taken with the Allegro Topolyzer (WaveLight Inc.) imaging system, and then a drop of 1% cyclopentolate was instilled on both eyes for preoperative retinal examination and cycloplegic otorefractometry measurement. Subsequently PH was dropped to neutralize the effect of cycloplegia and Topolyzer measurement repeated 1 hour after instillation of PH. Flat and steep keratometry values (K1 ve K2), astigmatism magnitude and axis, Q value, pupil diameter, and pupil apex x and y axis were compared before and after the instillation of PH.

Findings: Eighteen patients were male and 14 were female, the average age of the participants was 28.40 ± 7.58 years. After 1 hour of PH instillation, the mean intraocular pressure values in both eyes were measured 2.6 mmHg lower and pupil diameter was measured 1 mm greater compared to initial measurements. These values were statistically signifi cant (p <0.001). The change in other parameters was not significant.

Conclusion: There is no statistically signifi cant effect on the anterior segment parameters of pilocarpine drop applied after cycloplegia except for pupil diameter and intraocular pressure. The effect of cycloplegia can be neutralized by using pilocarpine drops in patients scheduled for anterior segment surgery. Keywords : Anterior segment parameters, pilocarpine hydrochloride, cyclopegia, topolyzer