MnSOD Val16Ala polymorphism associated with retinopathy risk in diabetes: a PRISMA-compliant Meta-analysis of case-control studies

AIM: To investigate the association of Manganese superoxide dismutase (MnSOD) Val16Ala polymorphism with diabetic retinopathy (DR). METHODS: PubMed, Embase, China National Knowledge Infrastructure, and Wanfang databases were searched. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the strength of the association. Subgroup, sensitivity, and cumulative analyses were performed. Publication bias was also analyzed. RESULTS: Eight studies were included in the pooled analysis. The MnSOD Val16Ala polymorphism was associated with the risk of DR under the dominant model (OR=0.66, 95%CI=0.48-0.91, P