Erythropoietin Is Increased in Aqueous Humor of Glaucomatous Eyes

PURPOSE: To determine the aqueous concentration of erythropoietin (EPO) in patients with and without glaucoma. METHODS: Prospective, comparative control study. Concentrations of EPO in the aqueous humor were measured using ELISA kits from 75 patients, of whom 55 had glaucoma (14 primary acute angle-closure glaucoma, PAACG; 26 primary chronic angle-closure glaucoma, PCACG; 11 primary open-angle glaucoma, POAG; 4 neovascular glaucoma, NVG), and 20 had cataract only as control. RESULTS: EPO concentrations in eyes with glaucoma (71.0 +/- 12.0 mU/mL) were significantly higher than those in eyes with cataract (6.4 +/- 0.8 mU/mL, P < 0.001). There were no significant differences (P = 0.421) between PCACG (28.84 +/- 3.9 mU/mL) and POAG (20.2 +/- 2.0 mU/mL); however, EPO concentrations in eyes with PAACG (118.5 +/- 14 mU/mL) were significantly higher than these two chronic subtypes of glaucoma (P < 0.001, respectively). Unusually high EPO concentrations were detected in four eyes with NVG (319.5 +/- 47.7 mU/mL). No effect of age, gender, different eyes, body mass index of the aqueous humor EPO concentration could be detected (P > 0.05). No significant correlation was found between aqueous humor and plasma EPO concentrations in PAACG and control group (P = 0.285, 0.500, respectively). CONCLUSION: Our prospective study suggests that the aqueous humor EPO concentrations are increased in eyes with glaucoma.