Objective: To analyze oxidative stress in primary open-angle glaucoma (POAG).

Methods: A case-control study including 90 eyes of 90 patients who needed antiglaucomatous surgery in the course of POAG (glaucoma group, n=50) and from patients who were operated of nonpathologic cataracts (cataract group, n=40). Free radical formation via lipid peroxidation by malondialdehyde-thiobarbituric acid reactive substances (MDA-TBARS) test and total antioxidant status in the aqueous humor samples of both groups were determined. Statistical analyses were carried out in relation to MDA-TBARS and total antioxidant status and their correlations with glaucoma risk factors.

Results: Significantly higher MDA-TBARS were detected in the POAG with respect to the comparative group of cataract subjects (P<0.001). Antioxidant activity was significantly lower in the POAG than in the cataract group (P<0.001).

Conclusions: Aqueous humor samples may be used for determining oxidative and antioxidant status in pathologic processes. Glaucomatous eyes had a significant increase in oxidative status and decreased antioxidant activity in the aqueous humor than the cataract eyes. Oxidative stress may play a pathogenical role in the POAG.