title: The effects of sildenafil on ocular blood flow.
abstract: OBJECTIVE
  To investigate the effects of sildenafil, a popular new drug in the treatment of erectile dysfunction, on ocular blood flow.
  
  
  METHODS
  This study was designed as a prospective, double-blind, placebo-controlled study. Twenty participants with erectile dysfunction were given a single oral dose of 100 mg sildenafil, while 10 participants with erectile dysfunction were given placebo. All the participants underwent routine systemic and ophthalmological examinations. Intraocular pressure, systolic and diastolic blood pressure and ocular blood flow (ophthalmic, central retinal, short posterior ciliary arteries) were measured in both eyes before and 1 hour after the dose of sildenafil or placebo. Ocular blood flow measurements were performed using colour Doppler ultrasonography.
  
  
  RESULTS
  None of the parameters were significantly different between the groups before study drug intake. Although central retinal artery velocities were not changed, ophthalmic artery and short posterior ciliary artery peak systolic velocity, end-diastolic velocity, and mean velocity values were significantly increased 1 hour after drug intake in the sildenafil group compared to the placebo group (p < 0.05).
  
  
  CONCLUSIONS
  Sildenafil causes a significant increase in blood flow in these arteries. A possible role of inhibition of phosphodiesterase-5 in vascular smooth muscles by sildenafil is implicated. Further studies are needed to investigate the effects of sildenafil on ocular blood flow in patients with senile macular degeneration, diabetic retinopathy and glaucoma.
authors.affiliation: Ophthalmology Department, Faculty of Medicine, Zonguldak Karaelmas University, Zonguldak, Turkey. mrtkksl@hotmail.com
authors.forename: Murat
authors.initials: M
authors.lastname: Koksal
authors.forename: Huseyin
authors.initials: H
authors.lastname: Ozdemir
authors.forename: Sebnem
authors.initials: S
authors.lastname: Kargi
authors.forename: Cetin
authors.initials: C
authors.lastname: Yesilli
authors.forename: Sühan
authors.initials: S
authors.lastname: Tomaç
authors.forename: Kamran
authors.initials: K
authors.lastname: Mahmutyazicioglu
authors.forename: Aydin
authors.initials: A
authors.lastname: Mungan
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D019842:Ciliary Arteries / Q000502:physiology*; D004311:Double-Blind Method; D007172:Erectile Dysfunction / Q000188:drug therapy; D005123:Eye / Q000098:blood supply*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000502:physiology*; D010879:Piperazines / Q000494:pharmacology*; D011446:Prospective Studies; D011687:Purines; D012161:Retinal Artery / Q000502:physiology*; D000068677:Sildenafil Citrate; D013450:Sulfones; D018615:Ultrasonography, Doppler, Color; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate; D015106:3',5'-Cyclic-GMP Phosphodiesterases