Additionally, patients with glaucoma exhibit decreased base excision repair (BER) enzymes, such as poly (ADP-ribose) polymerase (PARP1), 8-oxoguanine DNA glycosylase (hOGG1), and X-ray repair cross-complementing group 1 (XRCC1), suggesting that a disturbance of DNA repair may be involved in the pathogenesis of POAG [104]. This evidence concerns the gene OGG1 and open-angle glaucoma.