The Effect of Antioxidant Supplementation on Oxygen Induced Retinal Vasoconstriction in an Inflammatory Model in Humans

Abstract

Purpose: Dietary supplements have been found to be beneficial in age-related macular degeneration (AMD) due to their anti-oxidative properties. In the AREDS 1 study, a reduced progression to late stage AMD was associated with the use of a dietary supplement containing vitamin C, E, zinc and ß-carotene. In a previous study, we have shown that this AREDS 1 formulation restores the O2-induced retinal vasoconstrictor response of retinal vessels in a human endotoxin (lipopolysaccharide, LPS) model. The aim of the present study was to test the hypothesis that this abnormal O2-induced retinal vasoconstrictor response to LPS can also be modulated by a different formulation containing vitamin C, E, zinc, lutein/zeaxanthin, selen, taurine, Aronia extract and omega-3 free fatty acids.

Methods: In the present randomized, double masked, placebo-controlled parallel group study, 43 healthy subjects were included. The reactivity of retinal arterial and venous diameter, red blood cell (RBC) velocity and flow to 100% O2 breathing was investigated in the absence and presence of 2ng/kg LPS. Study participants were randomized to receive either placebo or nutritional supplements for 14 days. After that period, measurements were repeated.

Results: The decrease in retinal arterial diameter, RBC velocity and flow induced by breathing 100% O2 was significantly blunted after LPS infusion. Intake of the dietary supplement for 14 days almost restored the response of retinal hemodynamic parameters to 100% O2 after LPS administration. This effect was significant for retinal arterial diameter (p = 0.03 between groups), RBC velocity and flow (each p < 0.01 between groups).

Conclusions: In conclusion, the present study shows that 14 days intake of nutritional supplements reverses LPS induced alterations in the reactivity of the retinal vasculature The obtained results indicate that the used combination of antioxidants is capable of restoring retinal vascular endothelial function during oxidative stress.