RESUMO
OBJECTIVE: To evaluate the efficacy of Tanakan in patients with primary open-angle glaucoma (POAG) with respect to its influence on vascular endothelial function and oxidative stress. MATERIAL AND METHODS: Oxidative stress severity and antioxidant status were investigated in 52 patients with POAG divided into two groups. The effect of different treatment schemes on flow-dependent vasodilation and dynamic level of endotelin-1 (ET-1), which is a marker of endothelial dysfunction, was studied. RESULTS: In the main group glaucomatous optic neuropathy progressed significantly as compared to the baseline (p<0.05). A trend for a decrease in malondialdehyde-modified low-density lipoproteins (MDA-LDL) and plasma malondialdehyde (MDA) levels (p<0.1) was also found, which indicates the activation of antioxidant response and resolution of oxidative stress. Due to endothelial dysfunction, plasma ET-1 levels in glaucoma patients are on average 5 times higher than the corresponding median physiological concentration. After the treatment started plasma ET-1 levels reduced and 3 months later approached the normal range. Reactive hyperemia testing and assessment of flow-dependent vasodilation revealed a poor initial endothelial response in 64.6% of patients. During the treatment paradoxical vasoconstriction was noted in 12.4% of patients. After the treatment patients from the main group demonstrated a statistically significant increase in brachial artery diameter. CONCLUSION: Tanakan is showed to produce a positive effect on vascular remodeling in patients with POAG, which indicates its high antioxidant and antihypoxic activity. A significantly increased flow-dependent vasodilation found in the main group (especially 1-3 months after the beginning of the therapy) is thought to be due to an improved vasodilating ability of the vascular endothelium as the result of Tanakan use.