Viagra, Cialis Appear to Not Harm Vision

Two medications used to treat erectile dysfunction do not appear to damage vision when taken daily for six months, U.S. researchers said.

Dr. William H. Cordell of Lilly Research Laboratories in Indianapolis and colleagues conducted a randomized placebo-controlled study to assess changes in the retina among men taking tadalafil, sold as Cialis, or Sildenafil citrate, sold as Viagra.

A total of 244 healthy men, some with mild erectile dysfunction, age 30-65 were recruited. Of these, 85 were randomly assigned to take 5 milligrams of tadalafil, 77 to take 50 milligrams of sildenafil and 82 to take a placebo daily for six months.

The men underwent comprehensive ophthalmologic examinations including electroretinography -- a test to measure the electrical response of the light-sensitive rods and cones in the eye, used to detect diseases of the retina -- before, during and after treatment.

The study, published in the Archives of Ophthalmology, found that among the 194 men, 79.5 percent, who completed the study, no significant differences were found between treatment and placebo groups on electroretinography, visual function tests, measurements of intraocular pressure -- pressure within the eyeball -- or assessments of the anatomy of the eye.