Abstract:AIM: To compare the effect of orthokeratology (OK) and defocus incorporated multiple segment (DIMS) lenses on axial length (AL) elongation in bilateral myopic anisometropic children. METHODS: This retrospective study enrolled bilateral myopic anisometropic children categorized into two groups: OK lenses and DIMS lenses. The eyes with more myopia (MM) were divided into MM eyes and the fellow eyes with less myopia (LM) into LM eyes. According to the myopia degree in MM eyes, the subjects were further assigned to -0.50 to -3.00 D subgroup and -3.25 to -6.00 D subgroup. The t-test was used to analyze the changes in AL elongation between groups and AL differences in both eyes, and the relationship between AL changes and baseline data was evaluated by Pearson linear correlation analysis. RESULTS: Totally 202 children (8-14y) were divided into OK group with mean age 10.97±1.91y (46 males and 50 females) and DIMS group with mean age 11.05±2.06y (58 males and 48 females). After 1y, the changes of AL in OK-MM eyes (0.14±0.18 mm) were significantly slower than that in OK-LM eyes (0.20±0.19 mm) and DIMS-MM eyes (0.19±0.18; P<0.001, P=0.037). The OK-LM eyes and DIMS-LM eyes, DIMS-MM eyes and DIMS-LM eyes showed no statistically significant difference in AL changes (P=0.337, 0.381). In the -0.50 to -3.00 D subgroups, DIMS-LM eyes had better effect of AL control than OK-LM eyes, the changes of AL in OK-MM eyes and DIMS-MM eyes were no statistically significant. In the -3.25 to -6.00 D subgroups, the results were similar in total group. The change of AL in four subgroups was negatively correlated with age (P<0.05). CONCLUSION: OK lens can reduce binocular anisometropia; DIMS lens has similar effect on the control of binocular myopia in children with myopic anisometropia. The OK lenses are more effective than DIMS lenses with higher degrees of myopia, while DIMS lens retard AL elongation more effectively than OK lens when the spherical equivalent refraction of MM eyes is lower than -3.00 D.
