The most common type of glaucoma is open-angle glaucoma, which is the 2nd most common cause of blindness in the US. After adjustments for age and race, researchers showed that former and current cocaine users had a 45% increased risk of glaucoma . Men having open-angle glaucoma also had significant exposure to marijuana and amphetamines, though less than cocaine. Individuals having open-angle glaucoma as well as a history of illegal drug exposure were almost 20 years younger compared to individuals with glaucoma not having a history of drug exposure (54 as opposed to 73 years old).
While the mechanism of glaucoma vision loss isn’t completely understood, the majority of research has cantered on eye pressure increase slowly but surely injuring the optic nerve. The majority of people who develop open-angle glaucoma don’t have any symptoms until late in the disease process once considerable peripheral vision has been lost.
The researchers observed that among the 5.3 million veterans, of whom 91% were male, that made use of VA outpatient clinics in 2009, almost 1.5% had glaucoma. In the course of the same year, almost 3.3% of all those attended to in the outpatient clinics had been diagnosed with cocaine use or dependency.
Though this research established significant increase of glaucoma risk for individuals with a history of cocaine use, it doesn’t prove a causal relationship. It’s not likely that glaucoma preceded illegal drug use, since substance use usually starts in the teens or twenties.
The lasting effect of cocaine use on intraocular pressure, which is the only modifiable glaucoma risk factor, requires further study. Should other research confirm the association of cocaine use and glaucoma, substance abuse would be another modifiable glaucoma risk factor.