Advocates of medicinal marijuana cite evidence that hemp products can lower intraocular pressure (IOP) in people with glaucoma. However, these products are less effective than safer and more available medicines. Most research regarding marijuana use took place before some current medications with fewer side effects were available.
The high dose of marijuana necessary to produce a clinically relevant effect on IOP in the short term requires constant inhalation, as much as every three hours.
The number of significant side effects generated by long-term oral use of marijuana or long-term inhalation of marijuana smoke make marijuana a poor choice in the treatment of glaucoma, a chronic disease requiring proven and effective treatment.
The only marijuana currently approved at the Federal level for medical use is Marinol, a synthetic form of tetra hydrocannabinol (THC), the most active component of marijuana. It was developed as an antiemetic (an agent that reduces nausea used in chemotherapy treatments), which can be taken orally in capsule form. The effects of Marinol on glaucoma are not impressive.
To date, no studies have shown that marijuana or any of its approximately 400 chemical components can safely and effectively lower intraocular pressure better than the variety of drugs currently on the market.
Currently, there are no National Eye Institute studies in the United States concerning the use of marijuana to treat glaucoma.
The Glaucoma Research Foundation will continue to monitor the research community for any new and well-designed studies regarding the use of marijuana to effectively treat glaucoma.