Men experience vision loss after taking Viagra

• Fourteen men reportedly have had vision loss while taking the erectile dysfunctionerectile dysfunction drug Viagra, say ophthalmologists at the University of Minnesota.
• The men lost only part of their vision.
• Most of the affected men had other health problems and the structure of their optic nerve (the nerve that handles vision) raised their risk of the condition.
• "The number of cases is extremely small," says Howard Pomeranz, MD, PhD, who details seven of those cases in a new report.
• The condition is called nonarteritic anterior ischemic optic neuropathy (NAION).
• "The likelihood of this happening in an individual is pretty small.
• It's a question of weighing the relative risks," Pomeranz tells WebMD.
• He suggests that men taking or considering Viagra might want to check with their doctors about any risks.
• Pomeranz adds that he's also heard of three similar cases with another erectile dysfunction drug,erectile dysfunction drug, Cialis.
• "I don't know of any with Levitra yet," he tells WebMD.
• Viagra has been used by 23 million men, says Daniel Watts, a spokesman for Pfizer, which makes Viagra.
• He says that 103 clinical trials of Viagra have not had any reports of NAION.
• "We would say that there does not appear to be sufficient evidence to suggest a single identifying association of these events with Viagra therapy," says Watts.
• "I have no reason to doubt their statement," says Pomeranz.
• Still, he says that problems not seen in clinical trials later show up after a drug has been widely used for some time.