title: A double-blind placebo-controlled evaluation of the acute effects of sildenafil citrate (Viagra) on visual function in subjects with early-stage age-related macular degeneration.
abstract: OBJECTIVE
  To assess the effects of a single 100-mg dose of sildenafil citrate on visual function in men with early-stage age-related macular degeneration.
  
  
  METHODS
  Randomized double-blind placebo-controlled clinical trial.
  
  
  METHODS
  Nine men (mean age 71 years, range 59-85 years) with early-stage (minimal visual impairment and large drusen in the macula) age-related macular degeneration and 20/40 or better-corrected visual acuity in at least one eye were prospectively randomized to receive either placebo or sildenafil citrate (Viagra; Pfizer Inc, New York, New York) 100 mg as a single oral dose. After 7-14 days, they received the alternate treatment. Subjects underwent visual acuity, Amsler grid, color discrimination (D15), traffic light, Humphrey perimetry, and photo-stress testing in each eye before and at specific intervals within 8 hours after dosing.
  
  
  RESULTS
  Compared with placebo, no pattern of errors were evident in any visual function test following sildenafil administration. No statistically or clinically relevant changes from baseline were observed in visual acuity, Humphrey perimetry (corrected pattern standard deviation), D15 color discrimination, or photo-stress tests. No clinically relevant changes were observed in the Amsler grid or traffic light tests. Sildenafil treatment was associated with transient mild or moderate headache, flushing, and rhinitis. There were no visual adverse events spontaneously reported to the investigator.
  
  
  CONCLUSIONS
  A single 100-mg dose of sildenafil was well tolerated and produced no acute visual effects or exacerbation of preexisting visual impairment in nine men with early-stage age-related macular degeneration.
authors: Retina Foundation of the Southwest, Dallas, Texas 75231, USA. dbirch@retinafoundation.org
authors: David G
authors: DG
authors: Birch
authors: Steven M
authors: SM
authors: Toler
authors: William H
authors: WH
authors: Swanson
authors: Gary E
authors: GE
authors: Fish
authors: Alan M
authors: AM
authors: Laties
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000037:antagonists & inhibitors*; D000368:Aged; D000369:Aged, 80 and over; D003118:Color Perception / Q000187:drug effects / Q000502:physiology*; D003119:Color Perception Tests; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004341:Drug Evaluation; D006801:Humans; D008268:Macular Degeneration / Q000150:complications / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D010879:Piperazines / Q000008:administration & dosage* / Q000009:adverse effects / Q000493:pharmacokinetics; D011446:Prospective Studies; D011687:Purines; D012449:Safety; D000068677:Sildenafil Citrate; D013450:Sulfones; D014792:Visual Acuity / Q000187:drug effects / Q000502:physiology*; D058609:Visual Field Tests; D014794:Visual Fields / Q000187:drug effects / Q000502:physiology*
chemical_list: D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D000068677:Sildenafil Citrate; D015106:3',5'-Cyclic-GMP Phosphodiesterases