Survivors of myocardial infarction who take either sildenafil or tadalafil for erectile dysfunction may have increased risk for visual loss from non-arteritic anterior ischemic optic neuropathy (NAION), according to an article in the February issue of the British Journal of Ophthalmology.

"We found a strong link between use of Viagra or Cialis and NAION in men with a history of heart attack," said Gerald McGwin, PhD, lead author of the study. "We found similar results in men with hypertension that, while not as dramatic, are substantial enough to indicate that men with a history of heart disease should be warned of the risks of NAION before use of these medications."

The retrospective matched case-control study involved 38 US men diagnosed with the neuropathy at one academic ophthalmology practice and 38 controls without the optic disease. Medication history, including use of either sildenafil or tadalafil, was obtained via interview.

Overall, men with the neuropathy were not more likely to report use of either drug than their age-matched controls. However, there was a statistically significant correlation between drug use and neuropathy among men with a history of myocardial infarction. A correlation that did not reach statistical significance was found among men with hypertension.