The Effects of Viagra on Vision

by Howard D. Pomeranz, M.D., Ph.D

May 20, 2005

Since Viagra made its debut in 1998, it has done wonders to improve the lives of men suffering from impotence. More than 23 million men with erectile dysfunction have taken Viagra to mostly happy results.

Yet with all medications come side effects. People who take Viagra have had their share, including headaches, flushing, and a range of heart troubles. Recently, based on 14 cases, ophthalmologists have added permanent vision loss to the list of potential Viagra side effects.

Within hours of taking Viagra, these 14 men developed an eye condition that causes a permanent loss of vision. The condition, described as a stroke of the eye, is called nonarteritic ischemic optic neuropathy. It occurs when blood flow to the optic nerve is disrupted, resulting in an injury to the nerve.

Doctors identified the first case shortly after Viagra came on the market. Since then, 13 other men who took the medication have experienced a reduction in the quality of their eyesight, a loss of peripheral vision, or both. Some of the men lost half of their peripheral vision, while others became legally blind.

All 14 experienced the vision loss within 36 hours of taking Viagra for erectile dysfunction. In some of these cases, the loss occurred after the very first time they took Viagra. Others had been taking Viagra for quite some time before they lost some of their sight. Most of those who experienced vision loss after taking Viagra developed it in only one eye, but several of the patients went on to get the condition in their other eye.

Each of the 14 men who suffered a loss of vision shared a unique risk factor: a small optic cup–to–disk ratio. The cup–to–disk ratio, which can be seen with an ophthalmoscope, is an indentation in the center of the optic nerve where it inserts into the back of the eye. Most of the men had other health problems, such as high blood pressure, diabetes, smoking, and high cholesterol.

While many men have seen positive results from Viagra, the drug shouldn't be taken lightly. If you are considering taking Viagra, it's essential that you have an eye exam to determine if you have a small cup–to–disk ratio. If you do, think seriously before taking the drug or similar medications such as Cialis or Levitra. If vision problems occur after taking the medication, you should consult an eye doctor.

It's also important to tell all of your doctors—whether it's an ophthalmologist, dermatologist, or cardiologist—about your entire regimen of medications, even if it seems irrelevant to the type of specialist you are seeing. You never know what side effects might result from taking a new medication.

Howard D. Pomeranz, M.D., Ph.D., is an associate professor of ophthalmology at the University of Minnesota Medical School. He specializes in neuro–ophthalmology. He sees patients through University of Minnesota Physicians. This column is an educational service of the University of Minnesota. Advice presented should not take the place of an examination by a health–care professional. For more health–related information, go to http://www.healthtalk.umn.edu.