The subject of legalizing the use of marijuana for medicinal (and recreational) use has been much publicized of late. Currently 23 states and the District of Columbia have legalized marijuana for medicinal purposes. Four states have legalized marijuana for recreational use. Two groups are currently attempting to formulate ballot measures for legalization of medicinal marijuana in Missouri. So let’s dive into this a little bit as it pertains to what is probably its most socially well-known potential therapeutic effect – medical marijuana treatment for glaucoma. Its efficacy in treatment for glaucoma is “doobie-ous” at best. (See what I did there?)
Medical use of marijuana for various ailments goes back to ancient times. The association with treatment for glaucoma mostly stems from a couple of experiments done in the 1960’s and 1970’s. What a shocker there! I’m picturing a VW van laboratory. These experiments showed that the active ingredient in marijuana, known as THC, has a short-lived effect of lowering the subject’s intraocular pressure.
So let me backtrack a bit. Glaucoma is a progressive condition that causes damage to a patient’s optic nerve. Glaucoma is often (but not always) associated with elevated pressure inside the eye – intraocular pressure or IOP. Treatment for glaucoma centers on lowering the patient’s IOP to arrest any progression of nerve damage. To achieve this, the patient’s optometrist or ophthalmologist will usually prescribe eye drops. A satisfactory level of IOP reduction is sought that will prevent vision loss that will occur if left untreated.
Administration of THC (i.e. toking, getting baked, blazing, loading a fatty, sparking up, puffing the chronic tonic, etc.) will result in a measureable reduction in IOP. Unfortunately, this effect will only last for 3-4 hours. 24 hour consistent, stable IOP-lowering is needed to be a reliable treatment. Such as is the case with once-a-day glaucoma eye drops that can be taken with very few side effects. So for marijuana use to be an effective treatment, the subject would have to self-administer therapy roughly 8 times per day! For those of you that just shouted “Yippee!” – stay with me. Such frequent usage of marijuana carries with it very high likelihood of undesirable effects: lung damage, mental impairment, anxiety, loss of short-term memory, loss of concentration, excessive Dorito intake, etc. Another deal-breaker is pot’s effect of lowering blood flow to the optic nerve (called Ocular Perfusion Pressure), which negates its beneficial effect of lowering IOP.
Political and lifestyle choices aside, there are much better ways to treat glaucoma than with marijuana. I hope you found this blog helpful. Feel free to contact the docs at Columbia Eye Consultants Optometry if you have any questions.