My Penis Stuff

Earlier this year a number of reports surfaced in the scientific literature suggesting that Viagra might be associated with a very dramatic and dangerous retinal condition, known as nonarteritic anterior ischemic optic neuropathy (NAION), which could lead to permanent blindness.

In typical “sky-is-falling” style, some news items trumpeted this possible relationship to make it appear that almost everyone who took Viagra was at risk for serious damage to their eyes. The reality is quite different.

Viagra and the other PDE5 inhibitors, Levitra and Cialis, work by selectively inhibiting the action of a specific enzyme, PDE5, found in all the body’s vascular tissues (blood vessels). To some extent, these drugs also selectively inhibit another enzyme in the same family, PDE6, which tends to be located in the rod and cone receptors in the eye.

This is the reason for occasional mild to moderate vision side effects in men taking a PDE5. These effects, such as blue-tinged vision, lights that appear too bright, blurry vision, and difficulties with color discrimination, are almost always mild and usually disappear rather quickly.

Careful studies in people with and without eye disease have shown repeatedly that Viagra does not permanently affect visual acuity (sharpness), fields of vision, or sensitivity to visual contrast.

Over several years, isolated case reports in the medical literature have indicated that NAION and other serious visual conditions have been associated with PDE5 treatment. These reports represent the experiences of a handful of the more than 27 million men who’ve taken a PDE5 drug. At least some of these reported cases may be due to the fact that men who suffer from ED also tend to have multiple risk factors for the vascular problems that make a person vulnerable to NAION.

To date, there is no compelling evidence that taking Viagra places anyone at increased risk for NAION or related conditions affecting the retina or other important structures of the eye. Once again, the real story on this complex subject is not as simple as some news headlines.