Study: Impotency drugs may affect vision

The small study by the Birmingham school suggests men with a history of heart attack or high blood pressure should be warned before taking such drugs.

The findings are based on a study of 76 men with optic nerve damage diagnosed as non-arteritic anterior ischemic optic neuropathy. NAION is the most common form of optic nerve damage in older U.S. adults, with up to 6,000 people developing the condition every year.

Researchers said male study participants who had suffered a heart attack were 10 times more likely to develop optic nerve damage if they had taken Viagra or Cialis before their diagnosis.

Men with high blood pressure were also more likely to have optic nerve damage if they had taken the drugs, although that was not statistically significant.

The authors caution their study is small, but suggest the drugs may reduce the blood flow to the anterior optic nerve, resulting in tissue damage.

The research appears in the British Medical Journal.

Copyright 2006 by United Press International