Variability of serum oxidative stress biomarkers relative to biochemical data and clinical parameters of glaucoma patients

PURPOSE: The importance of oxidative stress in both the formation and the course of glaucoma has been known. Among the antioxidants, vitamin E possesses the specific effects and regulatory mechanisms of a neurohormone. The serum oxidant/antioxidant profile is reportedly altered in ocular pathologies. In this study, we analyzed the effect of the clinical parameters of glaucoma and biochemical data on antioxidants and serum oxidative stress markers as oxidation degradation products. METHODS: In this multicenter case control study, control and patient groups consisted of 31 healthy individuals and 160 glaucoma patients with no known additional abnormalities, respectively. We analyzed the oxidation degradation products malonyl dialdehyde (MDA), advanced oxidation protein products (AOPP), antioxidants, vitamins E and A, Serine (Ser), superoxide dismutase (SOD), glutathione peroxidase (Gpx), transferrine (TF), and total antioxidant capacity (TADA). All of these parameters and their relationships with serum cholesterol, glucose, protein, albumin, triglyceride levels, age, gender, visual acuities, intraocular pressure (IOP), c/d ratio, gonioscopic findings, medications, presence of pseudoexfoliation (px), central visual field and Optical Coherence Tomography (OCT) data, pachymetry, and Laplace values, were evaluated individually. Statistical comparisons were performed among them, and with the control group as well. RESULTS: TADA, AOPP, SOD, and Gpx were found to be decreased, and MDA, Ser, TF, vitamins A and E increased in the patient group. All data, excluding AOPP, varied significantly. Vitamin E was the most consistent parameter. CONCLUSIONS: In this study, the association between glaucoma and lipid oxidation was shown on a systematic basis, and the significance of vitamin E as a neuroprotective agent has been revealed once more.