This is a pretty common question I get at the office, mostly just out of pure curiosity. There have been a
lot of pop culture references to weed and glaucoma, so the question is, does it work?
Glaucoma is a disease that damages the optic nerve over time. This can cause a reduction side vision
and can lead to total blindness if untreated. The biggest indication for glaucoma is elevated eye pressure
(also know as IOP). The only way to control glaucoma progression is to lower IOP with prescription eye
drops or surgery depending on severity.
There were some studies done in the 1970s that showed that smoking marijuana lowered IOP in people
with glaucoma. After this study came out, there was much more research done to test the validity and
safety of using marijuana or its active ingredient THC to lower IOP. The results were that when patients
smoke marijuana or take a form of THC as a pill or injection that it does lower IOP but only for a short
period of time- three to four hours. To adequately treat glaucoma, you would then need to smoke
marijuana six to eight times a day to have consistently lowered IOP. This is a huge drawback and
obviously not a great idea.
Smoking enough marijuana to keep IOP down would leave you too impaired to drive or function. It can
also raise heart rate and decrease blood pressure, which in glaucoma patients would reduce the flow of
blood to an optic nerve that is already weak. This pretty much negates the benefit of the IOP lowering
effect of the drug. It would also be really expensive to smoke this much marijuana every day.
What about CBD? This is a derivative of cannabis that doesn’t have mood-altering effects. But there is
no research that shows CBD to be an effective treatment for glaucoma. In fact, it may do the opposite.
One study showed that it may actually increase IOP instead of lower it which would make glaucoma
worse.
The bottom line is that the largest association of eye physicians and surgeons in the world does not
endorse cannabis or its derivatives as glaucoma treatment. Absolutely do not self-medicate with
marijuana if you have glaucoma. Please speak to your eye doctor about the best options for managing
your glaucoma. There are many more safe and reliable ways to treat it.
