Effect of sildenafil on ocular haemodynamics

Purpose To study the effect of sildenafil, which is an effective agent for the treatment of erectile dysfunction, on ocular haemodynamics. Methods In this prospective study we examined the effect of a single oral dose of 50 mg sildenafil (Viagra) in a group of healthy young male volunteers, by using colour Doppler ultrasound imaging to measure haemodynamic variables in the central retinal artery (CRA), short temporal posterior ciliary artery (STPCA) and ophthalmic artery (OA). The following examinations were performed on both eyes immediately before and 1 h after a single oral dose of 50 mg sildenafil: visual acuity, intraocular pressure (IOP), colour vision, anterior segment, fundus appearance, resting heart rate, blood pressure and colour Doppler measurements. Results After sildenafil administration, peak systolic velocity, mean velocity and end-diastolic velocity significantly increased in the OA of both eyes. All Dopper indices remained non-significant for the CRA and STPCA of both eyes. Sildenafil did not cause any significant change in IOP, colour vision, visual acuity, systolic blood pressure or diastolic blood pressure. However, heart rate measurements increased significantly after sildenafil administration compared with baseline (p = 0.003). Conclusion The increased flow velocity in the ophthalmic artery seems to be due to a vasodilator effect of sildenafil.