GSTO2 and chronic closed-angle glaucoma: To investigate the association of glutathione s-transferase omega 2 (GSTO2) (142N > D) and transforming growth factor-β1 (TGF-β1) (869T > C) gene polymorphisms on the pathogenesis of two common types of glaucoma (including primary open-angle glaucoma (POAG) and chronic angle-closure glaucoma (CACG)) in the Iranian population.