Abnormal flow-mediated vasodilation in normal-tension glaucoma using a noninvasive determination for peripheral endothelial dysfunction

PURPOSE. To assess peripheral vascular endothelial function in patients with normal-tension glaucoma (NTG) by using a noninvasive method: endothelium-dependent flow-mediated vasodilation (FMD). METHODS. Forty patients with NTG and 40 healthy age- and sex-matched normal control subjects underwent measurement of FMD and endothelium-independent nitroglycerin-mediated vasodilation (NMD) via high-resolution, two-dimensional (2D) ultrasonographic imaging of the brachial artery. The patients also underwent blood sampling for biochemistry, lipid profile, and high-sensitivity C-reactive protein (hsCRP) analysis. RESULTS. The NTG group exhibited significant impairment of FMD compared with the control group (NTG: 2.64% +/- 2.22%, control: 5.96% +/- 2.50%, P < 0.001). Multivariate analysis demonstrated that the presence of NTG was the strongest independent predictor of FMD. The lipid profile and hsCRP did not differ significantly between the two groups. CONCLUSIONS. This study demonstrated impaired FMD in patients with NTG and the results provide evidence of a generalized peripheral vascular endothelial dysfunction in patients with NTG.