Effect of ildenafil citrate (viagra) on the ocular circulation

PURPOE: ildenafil citrate induce vaodilation by enhancing the mooth mucle relaxant effect of nitric oxide. We have previouly reported that nitrate compound, a different group of nitric oxide–mediated vaodilator ued mainly for the treatment of ichemic cardiac dieae, produce an increae in optic nerve head circulation and retinal venou vaodilation. The purpoe of the preent invetigation wa to evaluate the effect of ildenafil on ocular circulation. METHOD: In a double-blind, randomized, croover trial, 15 healthy male volunteer received 100-mg doe of ildenafil citrate (Viagra; Pfizer, Inc, New York, New York) or matching placebo on 2 eparate day. Laer Doppler flowmetry wa ued to ae foveolar choroidal and optic nerve rim circulatory parameter. Meaurement were obtained in one eye at baeline, 1 hour, and 5 hour after doing. Blood preure and intraocular preure were monitored, and perfuion preure wa calculated. REULT: Mean optic nerve head blood flow meaurement at baeline, 1 hour, and 5 hour were 11.6 ± 2.2 arbitrary unit (± D), 12.5 ± 2.8, and 12.1 ± 2.4 after ildenafil and 11.9 ± 2.5, 12.6 ± 3.1, and 13.0 ± 3.0 after placebo, repectively. When compared with placebo, no ignificant change in mean blood preure, intraocular preure, perfuion preure, or choroidal or optic nerve circulatory parameter were oberved after ildenafil treatment. The power to detect a 20% change in optic nerve head and choroidal blood flow after ildenafil wa approximately 90%. CONCLUION: In comparion with placebo, no ignificant change in optic nerve rim or foveolar choroidal blood flow wa oberved after treatment with ildenafil. Thi ugget that nitrate compound and ildenafil may differentially affect ocular circulation. Furthermore, no ignificant effect on intraocular preure, ytemic blood preure, or ocular perfuion preure were detected after ildenafil treatment.