LIG4 and open-angle glaucoma: In this study, we aimed to determine the frequency of polymorphisms in two DNA repair enzyme genes, Xeroderma pigmentosum complementation group D (XPD) codon 751 and X-ray cross-complementing group 1 (XRCC1) codon 399, in a sample of Turkish patients with POAG, and to evaluate their association with POAG development.