Effect of niacin on the choroidal circulation of patients with age related macular degeneration

To investigate the effects of niacin on choroidal blood flow in age related macular degeneration (AMD).

12 AMD patients with bilateral drusen and visual acuity of 20/40 or better in the study eye received a single oral dose of niacin (six subjects received 500 mg and six received 250 mg) or matching placebo on two separate occasions. Laser Doppler flowmetry was used to assess relative choroidal blood velocity (ChB(Vel)), volume (ChB(Vol)), and flow (ChB(Flow)) in the foveola of the study eye at baseline, 30, and 90 minutes after dosing.

In comparison with placebo, a statistically significant 24% increase in ChB(Vol) was observed 30 minutes after niacin administration (ANOVA, p = 0.01). In comparison with placebo, a significant decrease in ChB(Vel) of 23% was observed in the 500 mg group (p = 0.04) and no significant change in ChB(Vel) was seen in the 250 mg group at 30 minutes. No significant changes in ChB(Flow) were detected at 30 or 90 minutes. Also, there were no statistically significant changes in ChB(Vol) or ChB(Vel) at 90 minutes.

In comparison with placebo, a significant 24% increase in ChB(Vol) was observed 30 minutes after niacin administration. Owing to simultaneous decrease in ChB(Vel), however, no significant change in ChB(Flow) was detected.