Effect of sildenafil citrate (Viagra) on retinal blood vessel diameter

• Published in: American journal of ophthalmology 2002-06, Vol.133 (6), p.809-812
• Main Authors: Grunwald, Juan E., Metelitsina, Tatyana, Grunwald, Lili
• Format: Article
• Language: English
• Subjects: 3',5'-Cyclic-GMP Phosphodiesterases - antagonists & inhibitors; Adult; Biological and medical sciences; Blood Flow Velocity - drug effects; Blood Pressure - drug effects; Cardiovascular system; Cross-Over Studies; Double-Blind Method; Humans; Image Processing, Computer-Assisted; Intraocular Pressure - drug effects; Male; Medical sciences; Pharmacology. Drug treatments; Phosphodiesterase Inhibitors - pharmacology; Photography; Piperazines - pharmacology; Purines; Regional Blood Flow; Retinal Vessels - drug effects; Sildenafil Citrate; Sulfones; Vasodilation; Vasodilator Agents - pharmacology; Vasodilator agents. Cerebral vasodilators
• ISSN: 0002-9394; 1879-1891
• DOI: 10.1016/S0002-9394(02)01391-0

PURPOSE: The present investigation was conducted to evaluate the effect of sildenafil citrate (Viagra, Pfizer Inc., New York, NY) on retinal blood vessel diameter. DESIGN: Double-blind randomized, placebo-controlled, cross-over study. METHODS: Fifteen healthy male volunteers (mean age 39 years) received 100-mg doses of sildenafil or matching placebo on 2 separate days. Monochromatic fundus photography was obtained in one eye, and brachial artery blood pressure and intraocular pressure were measured at baseline, 1 hour, and 5 hours after dosing. The diameters of two major temporal veins and one artery were measured in a masked fashion from digitized photographic negatives. RESULTS: In comparison with placebo, no statistically significant change in average venous diameter was observed for the superior (analysis of variance [ANOVA], P = .97), inferior retinal temporal vein (ANOVA, P = .73), or the retinal temporal artery (ANOVA, P = .89) after sildenafil treatment. In comparison to placebo, there was no significant difference in the percentage change from baseline in venous or arterial diameter at 1 or 5 hours after sildenafil. The power to detect a 6.5% change in retinal vascular diameter following sildenafil was approximately 80% ( P = .05). CONCLUSIONS: These data suggest that at the maximum therapeutic dose used clinically (100 mg), sildenafil does not have a significant effect on retinal vascular caliber.