The influencing factors and the effect of myopia control in children treated with orthokeratology

Abstract

Objective: To analyze the influencing factors and the effect of myopia control in children treated with orthokeratology. Methods: It was a retrospective case series study. Data of 137 children from June 2016 to July 2020 in the Optometry Hospital of Wenzhou Medical University who were fitted with orthokeratology lenses and kept wearing them for 24 months were retrospectively reviewed. These children were divided into the modeling group (n=91) and verification group (n=46). The baseline conditions were recorded before they wore the orthokeratology lenses, including age, spherical equivalent refractive power (SER) and pupil area. The decentration distance was measured with a tangential difference map. Axial length (AL) changes of all children during 24 months were calculated. The influencing factors and the effect of myopia control were analyzed, and a regression equation was formulated with the modeling group. Then the influencing factors were imported with the verification group to compare the AL change differences between prediction and measurement. Results: There was statistical difference in AL between baseline and after wearing orthokeratology lenses for 24 months both in the modeling group [(25.16±0.90) mm vs. (25.56±0.82) mm; t=-10.119, P<0.001] and verification group [(25.29±0.71) mm vs. (25.67±0.69) mm; t=-8.785, P<0.001]. The AL changes in the modeling group showed significant correlations with baseline age (r=-0.365, P<0.001), baseline SER (r=0.308, P=0.003), pupil area (r=-0.260, P=0.013) and decentration distance (r=-0.352, P=0.001). The regression equation was as follows: y=1.609-0.056a-0.315b-0.009c+0.054d (y: AL changes, a: baseline age, b: decentration distance, c: pupil area, d: baseline SER). There was no statistical difference between prediction and measurement [(0.40±0.20) mm vs. (0.40±0.32) mm; t=-0.036, P=0.971]. Conclusion: Baseline age, decentration distance, baseline SER and pupil area contributed to predict the effect of myopia control after orthokeratology treatment.