Abstract:   Objective To compare the control efficiency on axial length growth among different orthokeratology lenses and spectacle lenses with aspherical lenslets in children with mild myopia in a year. Design  A retrospective cohort study. Participants  A total of 125 low myopic children were recruited.  Method  Myopic children were recruited and divided into three groups: Group A （42 patients wearing orthokeratology lenses(brand: Lucid), group B (44 patients wearing orthokeratology lenses(brand: CRT), and group C(39 patients wearing spectacle lenses with aspherical lenslets). Only right eye data were used for statistical analysis. One-way analysis of variance, LSD-t test and multiple linear regression were employed to compare the changes in axial length growth among groups at 3 months, 6 months, 9 months, and 12 months after wearing glasses and the incidence of corneal staining. Main Outcome Measures Axial length growth, the incidence of corneal staining. Results Axial length elongation in group A at 3 months， 6 months, 9 months and 12 months were (0.013±0.093) mm and (0.088±0.076) mm, (0.137±0.105) mm and (0.242±0.120) mm respectively. Axial length elongation in group B at 3 months， 6 months, 9 months and 12 months were (0.031±0.091) mm and (0.128±0.137) mm (0.178±0.141) mm and (0.291±0.139) mm respectively. No statistical difference (P>0.05) was found between the two groups in axial length elongation at the four time points. The increase of axial length in group C at 6 months and 12 months were (0.094±0.130) mm and (0.230±0.247) mm, which were no statistical difference compared with group A and group B (P>0.05) .After merging the data from Groups A and B, the axial length increase of the orthokeratology lens group at 6 months and 12 months was (0.104±0.113) mm and (0.270±0.131) mm, respectively, with no statistically significant difference compared to Group C (P＞0.05). After adjusting those covariate factors such as gender, age, initial SE, and initial axial length, the multiple linear regression analysis demonstrated that there was no significant difference in axial length growth between group A and group B at 3 months （β： 0.185， t=1.506， P=0.137， 95%CI： -0.010~0.075）, 6 months （β： 0.171， t=1.397， P=0.167， 95%CI： -0.018~0.103）, 9 months（β： 0.225， t=1.816， P=0.075， 95%CI： -0.006~0.124） and 12 months （β： 0.180， t=1.543，P=0.127， 95%CI： -0.016~0.124）. No statistical significant difference in the incidence of corneal staining (χ2=0.940, P>0.05)  was found between group A and group B. Conclusion In this study, there was no significant difference in the control efficiency of axial elongation and the incidence of corneal staining between VST-designed and CRT-designed  orthokeratology lenses. Spectacle lenses with aspherical lenslets demonstrated comparable performance with orthokeratology lenses on slowing axial length growth in low myopia.

Key words: Myopia, Orthokeratology; , Spectacle lenses, Aspherical lenslets