According to the Journal of Glaucoma, the Department of Veterans Affairs has recently found that cocaine use is predictive of open-angle glaucoma – one of the most common types of eye disease.

After the results were adjusted for age, gender and race, former cocaine users were 45% more likely to develop this blinding eye disease. Men with open-angle glaucoma also had increased exposure to amphetamines and marijuana, although not as much as cocaine.

Even more surprising, those with a history of cocaine use developed glaucoma almost 20 years earlier in life, at 54 rather than 73 years old,  leaving them with a longer time for this degenerative disease to progress to total blindness.

Although this study showed an increased risk for glaucoma in people with a history of drug use, it does not prove a cut and dry relationship. However, it is unlikely that glaucoma preceded the use of illegal drugs, since substance use typically begins in the teens or twenties.

Glaucoma is the second leading cause of blindness in the United States behind diabetes. And even though the exact mechanism of vision loss in glaucoma is not completely understood, we do know that an increase in eye pressure gradually damages the optic nerve. Because this damage is slow and gradual, most people who develop glaucoma have no symptoms until late in the disease process when they’ve already lost substantial peripheral vision.

The study’s author Dustin French, Ph.D a research scientist with the Department of Veterans Affairs said:

The association of illegal drug use with open-angle glaucoma requires further study, but if the relationship is confirmed, this understanding could lead to new strategies to prevent vision loss.

As of now, eye pressure is the only risk factor for glaucoma that we can control, which can be lowered using eye drops or surgery.  If an association of cocaine use and glaucoma is confirmed in more studies, substance abuse would be a second controllable risk factor for this blinding disease.