Marijuana (cannabis) and its chemical compounds, like CBD (cannabidiol), have been explored for their ability to treat glaucoma and other eye conditions. Glaucoma is an eye condition that requires constant treatment in order to properly control eye pressure, which is heightened in people with the disease.

While more research is needed, the American Academy of Ophthalmology (AAO) and the American Glaucoma Society agree that there are other safer treatment methods for glaucoma than marijuana at this time.*

What research says about marijuana and glaucoma

Glaucoma involves damage to the optic nerve and is notorious for reducing peripheral vision and, in some cases, vision loss. To prevent blindness, intraocular eye pressure (IOP) must be lowered, which involves continuous treatment.

In a research study from decades ago, cannabis was used as the mode of treatment in reducing eye pressure by 3 to 5 mm Hg. The research found that a person would have to ingest 18 to 20 mg of THC, a marijuana derivative, six to eight times every day. Aside from being costly, people who ingest this amount of cannabis would be unable to drive, operate machinery, and engage in many common activities. 

THC eye drops have also been shown to irritate and burn eyes, and they didn’t lower IOP nor did a sublingual (under the tongue) form of THC. In one study, glaucoma patients were asked to take THC-containing pills and/or cigarettes, but within nine months, all of the participants stopped due to side effects.

Lastly, cannabis, when ingested or smoked, does not only lower eye pressure—it also lowers blood pressure throughout the body. Consequently, this leads to less blood flow to the eyes. High blood pressure and decreased blood flow to the eyes may be risk factors for the progression of glaucoma.

What about CBD?

CBD comes with similar benefits as cannabis use but without the hallucinogenic effects and has also been studied for its effectiveness in treating glaucoma. One study found that CBD may increase IOP, which would worsen glaucoma. Further research, however, is needed as it relates to CBD use and glaucoma treatment.

Until further research is pursued, your doctor will likely treat your glaucoma with prescription eye drops or surgery, depending on the type of glaucoma and its severity. In the meantime, the AAO offers the following guidance for those curious about marijuana for glaucoma:

• The largest association of eye physicians and surgeons in the world does not endorse cannabis or its derivatives as a glaucoma treatment.
• Do not self-medicate with marijuana in an attempt to treat glaucoma. You can lose your vision if you don’t have a reliable, effective treatment for glaucoma.
• Speak with your ophthalmologist to find the glaucoma treatment option that’s best for you.
• Tell your doctor if you use marijuana.

*Turbert, D. & Gudgel, D. (2019, June 17). Does Marijuana Help Treat Glaucoma or Other Eye Conditions? American Academy of Ophthalmology. https://www.aao.org/eye-health/tips-prevention/medical-marijuana-glaucoma-treament

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