Abstract: Objective To analyze the effect of femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and trans-epithelial photorefractive kerectomy (Trans-PRK) on corneal curvature and corneal posterior surface height in high myopias. Design Prospective comparative case series. Participants 23 cases of FS-LASIK and 24 cases of Trans-PRK in high myopia patients within -8.00 D. Methods The corneal curvature and corneal posterior surface height were measured and analyzed with Pentacam analyzer before the surgery and 1, 3, 6 and 12 months after the surgery. Main Outcome Measures The corneal curvature and corneal posterior surface height. Results There were significant decreases in corneal curvature from both groups in different times after operation (all P<0.05). There were no significant differences in the corneal curvature that were compared between the two groups, except the 6 month and 12 month, in which K1 of Trans-PRK group were higher than FS-LASIK group (P<0.05). Meanwhile, there was no significant increase in corneal curvature at 6 months after operation in the FS-LASIK group, and no significant increase in corneal curvature at 3 months after surgery in the Trans-PRK group. The mean height of the posterior corneal surface in the Trans-PRK group was smaller than that in the LASIK group in different times (all P<0.05) except the 3 month (P=0.150). Conclusion Both FS-LASIK and Trans-PRK are safety used in the treatment of high myopia within -8.00 D. However, the Trans-PRK is more effective and safer for high myopia within -8.00 D, and with less effect on corneal curvature and posterior corneal surface height, and better recovery after 12 months follow-up. Therefore, Trans-PRK surgery is more suitable for patients with high myopia within -8.00 D. (Ophthalmol CHN, 2020, 29: 123-127)

Key words: myopia, laser in situ keratomileusis, trans-epithelial photorefractive kerectomy, corneal curvature, posterior corneal surface height