Statistical analysis
Statistical analysis was performed using SPSS for Windows (version 22.0; IBM-SPSS, Chicago, IL, USA). Paired t-test was used to compare preoperative and postoperative BCVA, IOP, and corneal ECC. The independent sample t test and the chi-square test were used to compare the two groups. P-values represent results for 2- sided tests, with values less than 0.05 considered statistically significant.