Amblyopia, Strabismus and Refractive Errors in Congenital Ptosis: a systematic review and meta-analysis.

Congenital ptosis may be associated with abnormalities of visual development and function, including amblyopia, strabismus and refractive errors. However, the prevalence estimates of these abnormalities vary widely. We performed a systematic review and meta-analysis to estimate the prevalence of amblyopia, strabismus and refractive errors in congenital ptosis. Cochrane, Pubmed, Medline, Embase, and Web of Science were searched by July 2017. We used random/fixed effects models based on a proportion approach to estimate the prevalence. Heterogeneity would be considered signifcant if the p values less than 0.1 and/or I greater than 50%. Subgroup analyses, meta-regression analyses and sensitivity analyses were utilized to explore the potential sources of it. A total of 24 studies selected from 3,633 references were included. The highest prevalence was revealed for myopia with 30.2% (95%CI 3.0-69.8%), followed by 22.7% (95%CI 18.5-27.8%) for amblyopia, 22.2% (95%CI 7.8-63.1%) for astigmatism, 19.6% (95%CI 16.5-23.2%) for strabismus, 17.3% (95% CI 13.1-22.9%) for anisometropia and 4.0% for hyperopia (95%CI 1.8-7.1%). Significant heterogeneity was identified across most estimates. Our findings suggest that amblyopia, strabismus and refractive errors in congenital ptosis are present in much higher percentage. This study highlights the importance of early diagnosis and timely treatment of patients with congenital ptosis.