Influence of orthokeratology lens treatment zone decentration on myopia progression: a systematic review with meta-analysis

Abstract

Background: Referring to the myopia control efficacy, the difference between the orthokeratology with decentration (OKD group) and orthokeratology with center-position (OKC group) as control group is not clear currently. Therefore, the aim of this meta-analysis was to investigate the effect of decentration on myopia control efficacy based on existing studies. Methods: We searched studies in PubMed, Embase and Wanfang up to January 2023 for relative containing the keywords "orthokeratology", "decentration" and their synonyms. Information including axial length measurements and decentration must be available and the included cases should not have obvious complications. The abstract, comment, review, meta-analysis, patent or case reports, studies with no sufficient data or including the combination of other control scheme were excluded. The risk of bias in the included studies was conducted by Newcastle-Ottawa Scale (NOS) and funnel plot. We pooled the mean differences (MDs) between the OKD group and the OKC group for axial elongation. Results: Six retrospective case control studies and one retrospective self-control study with a total of 624 eyes for OKD group and 343 eyes for OKC group were included for analysis. Although all the included studies indicated that the axial elongation in the severe decentration group (1.0 mm < decentration ≤1.5 mm) was less than that in the moderate group (0.5 mm < decentration ≤1.0 mm), we still uniformly selected the moderate decentration group as the OKD group to improve the persuasiveness of the results. According to the heterogeneity results (I2=16%, P=0.31), fixed effect model was chosen to get the merged results. One years' MD in axial elongation were -0.06 mm [95% confidence interval (CI): -0.09 to -0.04, P<0.01], indicating that orthokeratology with decentration shows more efficacy in myopia control than orthokeratology with center-position. Conclusions: Without decreased visual acuity {worse than 0.1 [logarithm of the minimum angle of resolution (logMar)]}, persistent corneal epithelial defects, glare or diplopia, orthokeratology with decentration (≤1.5 mm) showed more efficacy in myopia control than orthokeratology with center-position in children within 1 year.