Background Intermittent exotropia (IXT) is the most common type of strabismus, overminus lens therapy (OML) is frequently prescribed to treat IXT. Objectives To compare the effectiveness of OML and observation in the treatment of intermittent exotropia. Method An exhaustive search of the literature in Pubmed, EMBASE, Web of Science, and Cochrane Library databases was performed until July 2022. No language restrictions were used. The literature was rigorously screened according to eligibility criteria. Weighted mean differences (WMD) and 95% confidence intervals (CI) were calculated. Results A total of 4 articles with 561 participants were included in this meta-analysis. Our pooled results showed that OML demonstrated superior outcomes compared with observation, with greater decreases in distance and near exodeviation control (MD=-1.08, 95% CI: -1.96 to -0.20, P=0.02; OR, -0.64, 95%, -1.15 to -0.13; P < 0.001). Patients who received overminus lens therapy had a greater decrease in the deviation at both distance and near (OR, -2.88; 95% CI, -3.75 to -2.01, P < 0.001; OR, -3.44; 95% CI, -5.34 to -1.55; P < 0.001). There was no statistical difference between the two groups in terms of post-treatment proximal stereopsis (OR=0.01, 95% CI: -0.04 to 0.05, P=0.83). Conclusions The present meta-analysis indicated that overminus lens therapy was effective in improving the control and decreasing exodeviation angle of intermittent exotropia. However, it seemed not to be effective in improving the level of near stereopsis.

Objective To compare the effectiveness of part-time occlusion therapy（PTO） and observation in the treatment of intermittent exotropia(IXT). Methods An exhaustive search of the literature from Pubmed, EMBASE, Web of Science, and Cochrane Library databases was carried out until July 2022. No language restrictions were applied. The literature was rigorously screened against eligibility criteria. Weighted mean differences (WMD) and 95% confidence interval (CI) was calculated. Results A total of 4 articles with 617 participants were included in this meta-analysis. Our pooled results showed that PTO exhibited superior effects compared to observation, with greater decrease in exotropia control at distance and near (MD=-0.38, 95% CI: -0.57 to -0.20, P<0.001; MD=-0.36, 95%CI, -0.54 to -0.18, P<0.001), patients subjected to PTO therapy had greater decrease in distance deviations (MD=-1.95, 95% CI: -3.13 to -0.76, P=0.001). And there was greater improvement in near stereoacuity among PTO group in comparison with observation group (P<0.001). Conclusion The present meta-analysis indicated that part-time occlusion therapy showed a better effect in improving control and near stereopsis, and decreasing distance exodeviation angle of children with intermittent exotropia in comparison with observation.