Viagra has been associated with minor visual impairment before but now it is not so minor any longer. In 2005, reports of blindness among men using the drug have been probed by federal health officials. They however cautioned that the vision loss can be linked to the same illnesses that are direct to impotence.

A discussion was conducted between the makers of Viagra, Cialis and Levitra and the Food and Drug Administration. The topic of discussion was about what the labels of those drugs should state about the rare cases of varying degrees of vision loss which includes blindness. At issue was the rapid vision loss when blood flow to the optic nerve is obstructed. This is a condition called NAION or non-arteric anterior ischemic optic neuropathy.

There were 43 reports on NAION says the FDA. Most of it was men who were taking Viagra. But according to its maker, Pfizer, that these numbers are not that common considering that Viagra has been used by more than 20 million men worldwide since its approval in 1998. Of the most common causes of sudden vision loss in older Americans, from 1,000 to 6,000 cases a year, NAION is a usually condition. Two of the leading causes of impotence, diabetes and heart disease are included as risk factors.

The method on ensuring the safety of drugs already on the market by federal regulators and the drug industry are criticized. Now, this issue can never come at a better time. Since Merck & Co. pulled out its pain reliever VIOXX from the market because of possibly deadly heart trouble, pressure on the FDA to investigate reports of side effects has increased.

A lot of money is at stake with sales of Viagra rising 5% which is $438 million in the first quarter of the year. This is what Pfizer Inc. said in its recent quarterly filing with the Securities and Exchange Commission. After the news of the blindness case, shares have since declined on the New York Stock Exchange.

The treatment of erectile dysfunction was revolutionized by blockbuster drugs like Viagra and its competitors. These drugs already came with a strong warning. One is that it should not be taken along with nitrate containing drugs. The combination can cause significant drops in blood pressure. Another is since for some men, sex itself could be too much exertion. It shouldn’t be taken with those with heart conditions.

Temporary vision changes like seeing bluish tinges or having difficulty differentiating green and blue were also placed as warnings. Temporary effect on the retina, apparently are what may be effects on taking the drugs.

It is a different issue from NAION though. Earlier, the possibility of a link with blindness was publicly raised by a Dr. Howard Pomeranz of the University of the Minnesota. This was reported through an ophthalmology journal on seven patients reporting NAION vision loss has occurred within 36 hours of a dose of Viagra.

It is not directly know that Viagra use affects the blood flow to the eye but it is still probable that there is definitely some effect on the optic nerve.