The combined GSTM1 null/GSTT1+ genotype and GSTM1 null/GSTP1 Ile/Val or Val/Val was more prevalent in POAG patients, being a risk factor for POAG (OR: 2.4, 95% CI: 1.16–4.9; p=0.016 and OR: 2.7, 95% CI: 1.07–6.74; p=0.033, respectively). Here, GSTM1 is linked to open-angle glaucoma.