Oxidative DNA damage and total antioxidant status in glaucoma patients

PURPOSE To evaluate DNA damage markers and the antioxidant status of serum and aqueous humor in glaucoma patients. METHODS Aqueous humor and serum samples were obtained at the time of surgery from 28 patients with glaucoma and 27 patients with cataracts. Total antioxidant status (TAS) and 8-hydroxy-2´-deoxyguanosine (8-OHdG) levels of all samples were determined by spectrophotometric and enzyme-linked immunosorbent assay methods. RESULTS Aqueous levels of 8-OHdG were higher in glaucoma patients than in the cataract group (4.61±2.97 ng/ml versus 1.98±0.70 ng/ml, p=0.002). Serum levels of 8-OHdG were also higher in glaucoma patients than in the cataract group (17.80±8.06 ng/ml versus 13.63±3.54 ng/ml, p=0.046). The TAS levels of serum (0.55±0.13 mmol/lit versus 0.70±0.14, p=0.001), and aqueous humor (0.23±0.13 mmol/lit versus 0.34±0.15, p=0.001) in glaucoma patients were lower than in cataract patients. CONCLUSIONS Our findings provide evidence that oxidative DNA damage increases and TAS decreases in the serum and aqueous humor of glaucoma patients. These findings support the hypothesis that the formation of reactive oxygen species and/or a decrease in TAS may have an important role in the pathogenesis of glaucoma.