Does Viagra Really Cause Blindness

Marketed and manufactured by Pfizer Pharmaceuticals, Viagra is one of the most popular drugs on the market when it comes to treating erectile dysfunction in men. On May 27, 2005, the US Food and Drug Administration (FDA) confirmed that it was investigating a possible relationship between the use of Viagra and a type of blindness in men who take this drug. Experts are now currently examining the possibility that that the use of Viagra may cause NAION or non-arteritic anterior ischemic optic neuropathy, which sometimes results in permanent blindness in some people. However, it is also important to mention here that new studies are now showing a surprisingly high number of NAION patients are recovering on their own without treatment.

While FDA officials are further scrutinizing a possible link between Viagra and the partial loss of vision or NAION, it is still unclear whether the drug actually causes the blindness, or if it is just the root cause of the disease and impotency that are related. According to a spokesperson of the FDA, a formal ruling has yet been issued and the agency is still investigating this matter. However, to date no real solid evidence has come to light that Viagra is to blame for blindness in some 50 men who have taken this drug and have lost their sight. It is currently estimated that Viagra is consumed by more than 23 million men worldwide.

Another important factor that should be mentioned is that NAION can occur in men who are diabetic or have heart disease, the same conditions that can cause impotence and can lead to the use of Viagra.

The link between Viagra and NAION was first brought to light by Dr. Howard Pomeranz, MD, an eye expert at the University of Minnesota. In 2000, he reported the case of a man who developed NAION soon after he took Viagra, and since then there have been several other similar reports. In a study published in the Journal of Neuro-Ophthalmology Dr. Pomeranz noted seven new cases of men who developed NAION, possibly because of using Viagra.

So What Exactly is NAION?

NAION is one of the most common causes of unexpected or sudden vision loss in older Americans. It leads to swelling around the optic disc, where the optic nerve reaches the back of the eye. Ultimately, this swelling constricts the optic nerve and causes a rapid loss of vision. According to the National Eye Institute, around 6,000 people develop NAION each year.

The symptoms of NAION are often painless and usually appear without any notice. Researchers believe that about three quarters of NAION patients first discover their vision was blurry or impaired after getting up in the morning. The condition generally starts in one eye and can cause complete blindness if both eyes are affected. Those who have poor eyesight appear to have the highest chances for developing NAION, while people with diabetes, hypertension or high cholesterol also seem at greater risk for this disease. However much is still debated about NAION and its causes.

So the real question that now arises is, is there a risk from taking Viagra? The answer at the moment is not conclusive. Pfizer claims that in a review of 103 Viagra clinical trials with over 13,000 patients, no evidence of NAION or non-arteritic anterior ischemic optic neuropathy was found. The pharmaceutical giant also issued a press release saying that it found no link showing that NAION occurred more frequently in men taking Viagra, than men of similar age and health group who did not take the drug.

While a further careful study is still needed, it is advised by doctors to take Viagra cautiously. Viagra is already known to cause vision problems, though they are uncommon and usually go away themselves after a few hours. Viagra tends to cause temporary changes in color vision such as trouble telling the difference between blue and green objects or objects having a bluish color tinge to them. The eyes also become more sensitive to light, or blurred vision may occur.