Marijuana not a good treatment for glaucoma

I read with great interest the article in Sunday’s CDT regarding the marijuana medical treatment bill that recently passed the state House by a vote of 149-43. The bill contains 17 conditions that could be treated with the drug. One of the conditions named is glaucoma. Glaucoma is an eye disease that is treated by reducing intraocular pressure. The goal of glaucoma treatment is to stop the progression of visual field loss and structural optic nerve damage.

There may be really good medical reasons for marijuana treatment of the other 16 diseases named.

Unfortunately, glaucoma is not one of them for two main reasons. First, glaucoma management involves a nearly constant reduction of eye pressure over a 24-hour period. Pressure spikes can contribute to glaucomatous progression. Most of our pressure-reducing eye drops work for at least 12 hours and many work for more than 24 hours. While it’s true that smoking or oral ingestion of marijuana will reduce eye pressure, it only works for 3-4 hours. Thus, it would take 6-8 treatments, equally spaced every 3-4 hours, to adequately treat the disease on a daily basis. And even then, eye pressure spikes may still occur. Second, marijuana treatment often reduces blood pressure. If the blood pressure is reduced by too much, this can actually worsen glaucoma by reducing the blood supply to the optic nerve.

For these reasons, the American Optometric Association and the American Academy of Ophthalmology are both against using marijuana in the treatment of glaucoma.

Again, there may be excellent medical reasons to allow marijuana treatment in the state of Pennsylvania for certain medical conditions. Glaucoma should not be included as one of those medical conditions.

Dr. Mike Cymbor is a board-certified optometrist at Nittany Eye Associates and is a member of the Optometric Glaucoma Society.