title: Effect of sildenafil on ocular haemodynamics.
abstract: OBJECTIVE
  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).
  
  
  CONCLUSIONS
  The increased flow velocity in the ophthalmic artery seems to be due to a vasodilator effect of sildenafil.
authors.affiliation: Department of Ophthalmology, Adnan Menderes University, Aydin, Turkey. orucs@hotmail.com
authors.forename: S O
authors.initials: SO
authors.lastname: Dündar
authors.forename: M
authors.initials: M
authors.lastname: Dündar
authors.forename: I
authors.initials: I
authors.lastname: Koçak
authors.forename: Y
authors.initials: Y
authors.lastname: Dayanir
authors.forename: S B
authors.initials: SB
authors.lastname: Ozkan
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000187:drug effects; D019842:Ciliary Arteries / Q000187:drug effects / Q000502:physiology; D005123:Eye / Q000098:blood supply*; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D009880:Ophthalmic Artery / Q000187:drug effects / Q000502:physiology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology*; D011446:Prospective Studies; D011687:Purines; D012161:Retinal Artery / Q000187:drug effects / Q000502:physiology; D000068677:Sildenafil Citrate; D013450:Sulfones; D018615:Ultrasonography, Doppler, Color
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate