Variability of antioxidant defense enzymes in primary angle closure glaucoma patients in comparison with healthy subjects

Oxidative stress and antioxidant status may be associated with glaucomatous damage. The purpose of this study was comparison of the serum antioxidant status between primary angle closure glaucoma patients and healthy subjects. In this case- control study 66 primary angle closure glaucoma patients and 80 controls were enrolled. Peripheral blood sample obtained from patients. Superoxide dismutase(SOD) was assayed by inhibition the rate of adrenochrome formation. Catalase (CAT) was evaluated by decrease of H2O2 absorbance. Glutathione peroxidase (GPx) and Glutathione reductase (GR) were determined following NADP oxidation or reduction. Glutathione S-transferase (GST) was measured by increase in the absorbance of CDNB and glutathione conjugation. Antioxidant defense enzymes were significantly decreased in glaucoma patients over those of control groups. CAT (p<0.006), SOD (p<0.020) and GPX (p<0.004). A relative insignificant decrease of GR and GST activities was observed in glaucoma patients compared with healthy subjects. The present study supports the hypothesis that oxidative stress is an important factor in the pathogenesis of glaucoma. Although primary angle closure glaucoma has an anathomical basis but decrease in antioxidant defense enzymes activities may have a role in pathogenesis of this type of glaucoma.