Ever since Oklahoma State Question 788, the Medical Marijuana Legalization Initiative passed, many patients have asked about the role of marijuana in the treatment of glaucoma. Glaucoma is an eye disease that causes damage to the optic nerve. If untreated, it can progress to complete blindness. Experts agree high eye pressure is the most important risk factor for the development and progression of glaucoma. It is also one of the most controllable risk factors. As a result, lowering and/or controlling eye pressure has been the mainstay of glaucoma treatment.
To date, marijuana has been legalized for medical use in 36 US states, the District of Columbia, Guam, Puerto Rico and the U.S. Virgin Islands. California was the first state in 1996. As early as 1970 it was known that marijuana had the ability to lower intraocular pressure and since that time it has been considered as a treatment in various forms. While marijuana lowers eye pressure, smoking it has major drawbacks as a treatment for a chronic, long term disease like glaucoma. In contrast to conventional glaucoma eye drops, many of which last for 24 hours with as little as one drop, smoking marijuana reduces eye pressure for only 3-4 hours. To control eye pressure, it would require smoking marijuana 8-10 times per day including waking up in the middle of the night to smoke. This would not only cost significantly more than typical glaucoma treatments, but the physical and mental side-effects of frequent marijuana use would prevent the ability of most to function productively. Especially the elderly where this disease condition dominates. Side effects such as impaired judgement and coordination, increased paranoia, anxiety, elevated heart rate and irritation to the eyes would be persistent throughout the day.
Other means of administration of the active ingredient of marijuana, tetrahydrocannabinol (THC), include oral, sublingual, and eye drop instillation. These methods avoid the potential side effects of damage to the lungs from smoking, but are limited by the potential side effects listed above in addition to dry mouth, sleepiness, depression and confusion. With respect to THC eye drops, it has not yet been possible to formulate a THC eye drop that can actually penetrate the cornea sufficiently enough to provide an adequate pressure lowering effect.
Finally, although marijuana does lower eye pressure, lowering eye pressure in glaucoma patients is only one consideration in slowing the damage caused by glaucoma. Poor blood flow or “ocular perfusion pressure” produces inadequate blood supply to the optic nerve contributing to glaucoma damage. Since marijuana is known to lower blood pressure, it is possible that such an effect would result in additional damage to the optic nerve possibly reducing or eliminating whatever beneficial effect that was conferred by lowering eye pressure.
For these reasons, while marijuana does lower eye pressure, it is not recommended as a medical treatment for glaucoma. If you have questions about glaucoma, its treatment or diagnosis, please contact us in Stillwater at Cockrell Eyecare Center. We can be reached at 405-372-1715. We also invite you to visit our website at www.cockrelleyecare.com and like us on Facebook at Cockrell Eyecare Center!