Myocilin Polymorphisms and Primary Open-Angle Glaucoma: A Systematic Review and Meta-Analysis

Background: Glaucoma is the leading cause of irreversible blindness in the world. Recent evidence indicates a role for genetic susceptibility to primary open-angle glaucoma (POAG). The relation between myocilin polymorphisms and POAG susceptibility has been studied in different populations. Methods: A meta-analysis of 32 published genetic association case-control studies, which examined the relation between POAG and the R46X, R76K, Y347Y, T353I, and Q368X polymorphisms of the myocilin gene, was carried out. Results: In meta-analysis, significant associations were observed between POAG risk and two myocilin polymorphisms with summarized odds ratio of 4.68 (95% CI, 2.02-10.85) for Q368X and 2.17 (95% CI, 1.32-3.57) for T353I. Both Q368X and T353I were significantly associated with high-tension glaucoma, with summarized odds ratio of 4.26 (1.69, 10.73) and 2.26 (1.37-3.72). In Westerners, significant association was observed for Q368X mutation (odds ratio, 5.17; 95% CI, 2.16-12.40). However, in Asians it was for T353I (odds ratio, 2.17; 95% CI, 1.32-3.57). Conclusions: There is strong evidence that myocilin polymorphisms are associated with POAG susceptibility, and the prevalence of myocilin mutations might be ethnicity-dependent in Caucasians for Q368X and in Asians for T353I.