Abstract:  Objective To explore the changes of corneal higher order aberrations（HOAs） and their correlation with axial length changes after wearing orthokeratology(OK) lens. Design  Prospective case series. Participants A total of 118 children with moderate-low myopia , 219 eyes, from Beijing Aier New Vision Eye Clinic were included. Methods Vision acuity、corneal high-order aberrations, corneal topography and axial length were examined before(baseline) and at 1 day, 1week, 1 month, 3 months, 6 months and 1 year after overnight wearing OK lenses. Coordinates of the optical treatment zone center and pupil center were obtained from corneal topography to calculate lens decentration magnitude. The changes of corneal high-order aberrations at different time before and after wearing OK lens were compared by one-way repeated measures ANOVA, and the correlation between the changes of corneal high-order aberrations and the changes of axial length was analyzed by Spearman correlation analyses and regression analysis. Main Outcome Measures corneal high-order aberrations, spherical aberration, trefoil, vertical coma, horizontal coma and axial length. Results At 12-month follow-up, the total higher-order aberrations, spherical aberration, trefoil and horizontal coma of cornea were significantly increased (P<0.05). There was no significant difference in vertical coma before and after wearing glasses (P=0.869). The change of horizontal coma was related to the decentration of the lens (r=0.181, P=0.010). The total corneal high-order aberration, spherical aberration and horizontal coma in the moderate myopia group were significantly higher than those in the low myopia group at each time point after wearing orthokeratology lens (P<0.05). Linear regression analysis showed that the increase of axial length was related to age and baseline spherical diopter(R2=0.298, P<0.001), and had no significant correlation with the change of corneal higher-order aberrations. Conclusions At 12 month after OK lens wear，the total higher-order aberrations, spherical aberration, trefoil and horizontal coma of the cornea increased significantly, while the vertical coma did not change significantly. The change of horizontal coma is related to the off-center amount of the lens. The increase of axial length was related to the initial age and the diopter before wearing OK lens. For children with moderate mypoia, attention should be paid to the higher corneal HOAs after lens wear. However, corneal HOAs alone cannot predict the rate of axial length progression; age, baseline refraction and the dynamic changes in axial length itself should still be monitored.

Key words: Myopia, Corneal high-order aberration, Axial length, Orthokeratology