Meta-analysis was used to evaluate the effect of peripheral defocus soft corneal contact lens (PDSCLs) and single vision soft contact lens (SVSCLs) on the control of juvenile myopia.

MEDLINE, EMBASE and Cochrane retrieval Library database by computer, and the search results are included in the study cases, will use PDSCLs as intervention group, will use SVSCLs or glasses as a control group, participants were school-age children. Using the evaluation method of Cochrane system, two reviewers independently collected data to extract information from the selected study (including the author, publication year, country or region, research center, quantity, age, with added value, sample size, follow-up time, the number of lost, intervention measures and results and test methods), and through the Downs and Black scoring system to assess the quality of clinical trial included in the test. In two intervention groups, the difference of diopter and eye axis was calculated by weighted mean difference (WMD), and the 95% confidence intervals were calculated. Heterogeneity was examined by I² statistics, when the P<0.1 (or I²>50%) was estimated using a random effects model (I-V heterogeneity) to account for significant heterogeneity. Otherwise, we use the fixed effects model (inverse variance) to evaluate. The two groups of refraction and axial length werecompared using Z test.

A total of 542 studies were retrieved, of which a total of 5 high quality clinical trials met the inclusion criteria of the study. In the end, a total of 4 studies were included in the Meta analysis, including 310 cases of wearing PDSCLs and 298 cases of wearing SVSCLs. All studies were single center. In these studies, there was a crossover trial, in order to prevent the time interval between the two dry expectations, this study included only the results of the first intervention. Three of the four studies were randomized controlled trials, and the other one was randomized controlled trial (RCT). In the intervention group, the added value of the one studies was + 2.50 D, and the other 3 items were + 2.00 D. 4 patients were followed up for a period of 10 to 24 months. Compared with SVSCLs, PDSCLs delay the progression of myopia in children with myopia of 0.27 D (95% confidence interval: 0.20~0.34), the difference was statistically significant (Z=7.78, P<0.05); slow axial length growth of 0.12 mm (95% confidence interval: -0.15~-0.09), the difference was not statistically significant (Z=0.54, P>0.05), need to expand the sample for further study. During the follow-up period of 12 and 24 months, the WMD of the refractive index of the intervention group and the control group were 0.29 D (95% confidence interval: 0.20~0.39) and 0.13 mm (95% confidence interval: -0.17~0.08). The WMD of the axial length of the intervention group and the control group were 0.26 D (95% confidence interval: 0.15~0.36) and 0.12 mm (95% confidence interval: -0.17~0.07).

Overall, compared with SVSCLs, PDSCLs is more effective in slowing the development of myopia, while the reliability of the results need to be further studied.