Long-Term Efficacy of Orthokeratology to Control Myopia Progression

Objectives:To assess the efficacy of orthokeratology in controlling the rate of myopia progression in children and investigate the factors associated with axial length (AL) growth rate with an average of 48 months of orthokeratology lens wear.Methods:As a retrospective study, 84 subjects underwent relatively complete ophthalmologic examinations. After initial lens wear, AL was measured on average every 12 months. The linear mixed-effects model (LMM) was used to compare the differences in AL growth rates at each time interval. The contribution of the independent variables to AL change was assessed using multiple linear regression.Results:In the LMM, there was a significant difference in the AL growth rate (P<0.001) at each follow-up. The growth rate of AL was associated with initial AL, spherical equivalent refractive errors (SERs) and diameter of lens (P=0.045, 0.003 and 0.037, respectively). When the baseline age was included as a factor, the influence of initial AL and SER became insignificant in the analysis, whereas age and diameter of lens were significantly correlated with the growth rate of AL (P<0.001 and P<0.001, respectively). There were significant differences in growth rates among different age groups.Conclusions:Results of the study demonstrated that the factors associated with lower growth rate in AL were older age and longer diameter of lens.