Effect of niacin on retinal vascular diameter in patients with age-related macular degeneration.

PURPOSE: Niacin is a B vitamin well-known for causing vasodilation and flushing. The purpose of this study was to investigate its effect on the retinal vasculature of patients with age-related macular degeneration (AMD).

METHODS

Twelve patients with AMD were enrolled in a double-blind, randomized, placebo-controlled, crossover trial. Fundus photographs of the posterior pole were taken at baseline, 30 min, and 90 min after a single dose of niacin or placebo. The protocol was repeated after a washout period using the alternate study drug. The diameters of two veins and one artery on each image were measured.

RESULTS

An analysis of variance for repeated measures comparing the effects of niacin with those of placebo demonstrated a significant increase in the inferior temporal retinal artery diameter (p = 0.01), with a 5.3 +/- 7.7% increase at 30 min (p = 0.05) and 5.8 +/- 5.0% increase at 90 min (p = 0.003). No significant changes were observed in the temporal retinal veins.

CONCLUSIONS

Our results suggest that niacin produces vasodilatation of retinal arterioles. Further studies are needed to ascertain whether niacin treatment may be beneficial in retinal ischemic diseases.