So, here in Oklahoma Marijuana is legal for medical use, but not for recreational use. As an Eye Doctor I get asked on a regular basis if marijuana is helpful for glaucoma. In order to cover this topic properly I must start by talking about what glaucoma is and what it does. In a nut shell glaucoma is when the pressure is too high for the eye to handle. This damages the weakest part of the eye which is the optic nerve.
Marijuana and Glaucoma
So, with that very basic understanding let’s dive into treatment options for glaucoma and if marijuana is an option. All treatments that lower the eye pressure decrease the risk of developing damage that defines glaucoma.
Currently there are several different options to lower the eye pressure that are accepted by the medical community. These options include eye drops, laser surgery, or traditional surgeries. Sometimes one or more of these treatment options do not get the pressure to the level the Eye Doctor would like. In these situations, it is understandable to look for alternative therapies.
One commonly discussed alternative option is marijuana. This is discussed because smoking marijuana does lower the eye pressure. However, the less often considered fact is that marijuana’s effect on the eye pressure only lasts about 3 hours. Also, the amount that needs to be consumed is about 19mg of THC. This means that to lower the eye pressure all day it would have to be smoked around 8 times a day for a total of about 152mg of THC.
Something else to consider is that marijuana’s mood altering effects can cause problems with operating machinery, driving, and functioning at maximum mental capacity. Also, marijuana cigarettes can contain hundreds of compounds that damage the lungs. Smoking every 3 hour can cause lung irritation.
Edibles for Glaucoma
Other means of administering tetrahydrocannabinol (THC), include by mouth and under the tongue also known as edibles for glaucoma in the Optometric industry. These methods avoid the harmful effect of marijuana smoke on the lungs. However, these methods are limited by the other systemic side effects, such as drowsiness. A research study done in the 1970’s regarding the usage of marijuana as a treatment for glaucoma had 100% of the participants drop out within 9 months due to the side effects and time constraints involved with the every 3 hour usage. THC eye drops have yet to be shown to reduce the eye pressure, but research is still happening in that arena.
Although marijuana does lower the eye pressure, it also lowers blood pressure. There is some research suggesting that lower blood pressure could result in reduced blood supply to the optic nerve. This can in turn harm the optic nerve. This concept has caused some in the medical community to question if the benefit from lowered eye pressure is offset by the decreased blood pressure. For these reasons, marijuana cannot be recommended at the current time as a viable treatment option for glaucoma.
CBD and Glaucoma
Most patients are surprised when I tell them that CBD actually makes glaucoma worse. Research that came out in 2019 shows that CBD oil makes the eye pressure higher. So, using CBD oil for glaucoma is not an option and people with glaucoma should be cautious when using CBD oil. In other words, CBD is not good for glaucoma in any form or fashion according to current research.
Marijuana for Glaucoma
So, in conclusion while marijuana does lower the eye pressure it is not a good treatment option for glaucoma. The reasons include; smoking marijuana 8x a day, the cost for that volume of marijuana, the lung damage from inhaling that much smoke, the mental side effects, and the possible offset of the benefit by the lowered blood pressure.