RESUMO
PURPOSE: To compare the effects of orthokeratology (OK) for early childhood myopia control and to contrast with clinical trial data published by various investigators. METHODS: The researchers studied papers in Pubmed, Embase, Clinicalkey and CNKI published before October 31, 2021, identified by searching for RCT (Randomized controlled trials) and cohort studies on the treatment of early childhood myopia with orthokeratology. The researchers extracted the mean deviation for axial elongation at each year of follow-up between the orthokeratology groups and control groups (myopic spectacles) and analyzed the results with stata 12.0 software. RESULTS: The meta-analysis included 4 RCTs and 9 cohort studies with 744 samples (OK group 362, control group 382), aged 6 to 17 years. There was evidence of heterogeneity (I2>50%) on axial elongation in the included data. At 1 year, 2 years, 3 years, 4 years, 5 years and 7 years of follow-up, the axial elongation figures were -0.15mm (95% [CI] (confidence interval), -0.16 to -0.14) in all studies, -0.28mm (95% [CI], -0.33 to -0.23) in all studies, -0.36mm (95% [CI], -0.45 to -0.27) in one study, -0.42mm (95% [CI], -0.52 to -0.32) in one study, -0.42mm (95% [CI], -0.77 to -0.07) in one study, -0.44mm (95% [CI], -0.65 to -0.23) in one study. The heterogeneity disappeared after dividing subgroups according to the length of follow-up. CONCLUSION: Compared with the control group, the first two years of orthokeratology can control axial elongation in children and effectively delay the development of myopia. However, this effect was not obvious after 2 years. It is recommended to prescribe orthokeratology for two years to obtain the best effect. The length of therapy must be taken into account when studying the effects of orthokeratology.
