Effects of sildenafil citrate (Viagra) on choroidal congestion.Ophthalmologica. 2002 Nov-Dec; 216(6):455-8.O
This study evaluates the effect of sildenafil on choroidal vascular congestion and its correlation with visual effects. Thirteen healthy subjects were randomized to a sildenafil group (n = 7, 3 M, 4 F), who received 200 mg of sildenafil, and a control (n = 6, 5 F, 1 M) group, who received no drug. Measurements of choroidal thickness with ultrasonography, color vision with Desaturated Panel D-15 Test, and contrast sensitivity with CSV-1000e charts (Vector Vision) were performed at baseline and at 90 and 180 min. Mean choroidal thickness and contrast sensitivity did not change significantly relative to baseline in either group. However, the variance in differences between repeat and baseline measurements of choroidal thickness was significantly higher at 90 min (p = 0.003) in the sildenafil subjects. Color discrimination error scores increased after sildenafil but did not correlate with changes in choroidal thickness. An oral dose of 200 mg of sildenafil caused small inconsistent changes in choroidal thickness, which did not correlate with visual effects.