Object The aim was to review all published studies that investigated the association between OPA1 polymorphism and the risk of primary open-angle glaucoma (POAG)

Methods  we made this meta-analysis through reviewing 9 publications with a total of 1132 normal tension glaucoma patients (referred to as NTG group), 1206 high tension glaucoma patients (referred to as a HTG group) and 1653 healthy controls. The allelic frequency and genotypes of OPA1 were extracted for analysis in STATA 11 and RevMan 5.1. Crude odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of this relationship between the OPA1 polymorphism and POAG (HTG/NTG) risk.

Results  (1)Using genetic model analysis, the IVS8 +4C>T polymorphism was found to increase the risk of NTG in a dominant model, which indicates that T allele carrier (TT + CT) of IVS8 +4C>T (rs166850) polymorphism are at a higher risk of NTG than homozygotes CC, the total random effects OR was 2.55(95%CI: 1.70–3.82, P<0.01). (2)The IVS8 +4C>T polymorphism also increased NTG risk in a complete overdominant model, especially in East Asian and African subjects. (3) IVS8 +32T>C may be  a significant risk modifier for IVS8 +4C>T. (4)The IVS8 +4C>T and IVS8 +32T>C polymorphisms have no association with HTG susceptibility in our study. In addition, there was some extent heterogeneity when analyses were performed in various models. There was no publication bias.

Conclusions  We concluded that the IVS8 +4C>T (rs166850) polymorphism appears to be a risk factor for NTG in a dominant model, and might be a risk factor for NTG occurrence. The association warranted further studies.