September 15, 2013
I had a patient come in for an exam awhile back. No, I don’t think this guy had been smoking marijuana (but you never know). He worked in a marijuana dispensary. Yep, we’ve got these little businesses all around Denver and Colorado that sell medical marijuana. And soon, there will be legal retail marijuana sales here starting January 1st, 2014. If you want to start a business selling some bud you better get here quickly!
Anyway, the patient said he sees a lot of prescriptions for marijuana used to treat glaucoma. Yeah, right. The National Institutes of Health studied the effects of eye pressure and marijuana use (tetrahydracannibinol, THC) and found that marijuana only provides a few hours of eye pressure reduction. If you want to keep your eye pressure down you have to smoke (or take the equivalent of) 6 or more joints a day. And that pretty much ruins your day I’d say.
But there’s more to marijuana and the eyes than trying to treat glaucoma (by the way, see a doctor that doesn’t sell marijuana if you have glaucoma). There’s the pupil thing. Meaning, people are suspected of being high (on THC) if their pupils are dilated. It may be because they were smoking marijuana but it’s possible it wasn’t the marijuana that made their pupils dilate. Marijuana users can have different responses and even pupil constriction. It might be something that was added to the marijuana either before they bought it or after. I’ll call it an adjuvant. But in reality, the additive might be some other drug or ingredient added for extra effect. And just to say, marijuana is also not necessarily all that organic depending on who grew it but neither are a lot of fruits and vegetables we might buy at the store.
There is an eye/ocular side-effect that is pretty common though and that’s conjunctival injection, aka, red eyes. THC is a vasodilator which means it makes blood vessels larger and that can make things redder looking in the eye. Bigger blood vessels, redder eyes. But red eyes could occur just from smoke getting into the eyes or a lot of other things (maybe one of those adjuvants). The over-the-counter drops for getting the red out are called vasoconstrictors. The chemicals in those eye drops constrict blood vessels and make them smaller. Thus, a marijuana user might also be a “get the red out” Visine user (or similar product).
You guys stay tuned to what happens starting next year in Colorado. This will be interesting.