EPO and open-angle glaucoma: To compare the aqueous concentration of erythropoietin (EPO) in eyes with primary open-angle (POAG), pseudoexfoliative (PXFG), and neovascular (NVG) glaucoma with age-matched eyes with cataracts, and to correlate its concentration with other factors including age, gender, intraocular pressure (IOP), type of glaucoma, and severity of glaucoma.