Decreased Total Antioxidants in Patients with Primary Open Angle Glaucoma

Purpose: To evaluate total antioxidant status (TAS) in the plasma of primary open angle glaucoma (POAG) patients and to compare it to that of the control group. Additionally, we aim to investigate the association of various POAG clinical indices with TAS level. Materials and Methods: Plasma samples were obtained from 139 POAG patients and 148 glaucoma- free controls of matching age, sex, and ethnicity. TAS in all samples was determined by spectrophotometric and enzyme-linked immunosorbent assay methods. We studied the possible association of the TAS level with various clinical indices relevant to POAG. Results: The mean (+/- SD) total antioxidant (TAS) value was lower among patients: 0.47 (+/- 0.32), than controls: 0.97 (+/- 0.43) and this difference was statistically significant (p < 0.0001). TAS concentration was not significantly associated neither with the level of intraocular pressure, nor with number of anti-glaucoma medications (p = 0.532 and 0.084 respectively). However, TAS level shows a trend towards reduction with increased severity of glaucoma presented in a reversed significant association with cup/disc ratio (p = 0.043). Conclusions: Our findings provide evidence that TAS decreases in the plasma of POAG patients and that it may play a role in POAG pathogenesis. Association of TAS level with increased cup-to-disc ratio highlights TAS potential role as a predictive-marker for POAG-severity.