Abstract: Objective To explore the Influence of TransPRK and LASEK on postoperative vision, diopter and corneal biomechanical properties in myopic eyes with thin cornea. Methods Totally 118 patients with myopia and astigmatism were enrolled, in which data of 118 right eyes were selected and analyzed, 61 eyes of 61 patients undergoing TransPRK were designed as TransPRK group, and 57 eyes of 57 patients undergoing LASEK as LASEK group. The uncorrected visual acuity(UCVA), diopter, central corneal thickness(CCT), posterior corneal surface height, aspheric parameter Q value, corneal hysteresis(CH), corneal resistance factor(CRF)and corneal aberration between two groups were compared 1 week, 1 month, 3 months, and 6 months after operation. Results There were no statistical difference between two groups regarding the proportion of postoperative UCVA reaching or exceeding preoperative best corrected visual acuity(BCVA)one week, 1 month, 3 months, and 6 months after operation. The proportion of patients’ diopter reaching or exceeding preoperative desired diopter correction was higher in TransPPK than LASEK group 1 week and 1 month after operation(P<0.05). Compared with pre-operation, the posterior corneal surface height shifted rearward slightly(P<0.05), but aspheric parameter Q value didnt change significantly(P>0.05)in postoperative 6 months in the two groups. The CH, and CRF value on postoperative 1, 3 and 6 months were significantly lower than pre-operation in two groups(P<0.05). The coma aberration, spherical aberration, and higher order aberration after postoperation were higher than pre-operation(P<0.01), but there was no significant difference between two group regarding CH, CRF, coma aberration, spherical aberration, and higher order aberration at each time point after operation. Conclusion TransPPK, as emerging surface refractive surgery, is effective and safe in treating myopic eyes with thin cornea, with stable diopter, for it is operated not on the eyeball and has little effect on the corneal surface morphology and biomechanical properties.

Key words: Cornea, Transepithelial photorefractive keratectomy, Laser epithelial keratomileusis, Corneal biomechanics, Diopter, Myopia