Study: Long-term use of impotence drugs does not change visual function
NEW YORK A new study published in the April issue of Archives of Ophthalmology detected no changes in visual function, signs of retina damage or intraocular pressure after the daily use for six months of erectile dysfunction treatments.
Viagra (sildenafil) or Cialis (tadalafil) are commonly used to treat erectile dysfunction and are also being considered for use in other disorders. These drugs, however, have been associated with visual side effects, such as blue-tinged or blurred vision and light sensitivity, explained Eli Lilly's William H. Cordell, M.D.
Cordell's team conducted a study of healthy men with or without mild erectile dysfunction, between 30 and 65 years old and with no ophthalmologic abnormalities or risk factors. The men were randomly assigned to daily treatment with Viagra 50 mg, Cialis 5 mg, or placebo. The analysis included 155 men who completed 6 months of treatment and 212 men who completed three months.
Following treatment with the two erectile dysfunction drugs, no clinically important side effects or differences were detected among the three groups at three months, 6sox months, or at a posttreatment follow-up four to six weeks later.
Similarly, treatment had no effect on visual acuity, color discrimination, intraocular pressure or any other functions.
No cases of nonarteritic anterior ischemic optic neuropathy or other serious ocular damage occurred during the trial, the authors noted. Nonarteritic anterior ischemic optic neuropathy is characterized by sudden visual loss, swelling of the optic disc and sometimes hemorrhaging in the area. The condition is usually permanent, and up to 20% of patients can suffer total visual loss.
The authors conclude that the findings indicate no cumulative damage or effect of clinical significance for 5 mg of Cialis or 50 mg or Viagra taken daily for six months, although they caution that their findings cannot be generalized to patients who have coexisting systemic or ocular disease.