Furthermore, DNA methylation studies identified DMRs in glaucoma-related genes, such as PLEKHA7 and PITX2, between primary open-angle glaucoma (POAG) patients and normal Schlemm’s canal cells (Fraga and Esteller, 2007), reinforcing the link between methylation and glaucoma pathology. This evidence concerns the gene PITX2 and open-angle glaucoma.