The Cannabis Glaucoma Connection-Is Marijuana an effective treatment for Glaucoma?
As Toronto optometrists, we feel we should educate our patients on their eye health. This includes treatments for diseases such as glaucoma, and the prevalent belief that marijuana is one of those effective treatments. With medical marijuana and recreational legalization of cannabis you may be questioning whether cannabis, with its long association as a treatment for various medical conditions, is a good treatment for glaucoma. The medicinal properties of cannabinoids have made them an accepted treatment for patients suffering from chronic pain, cancer, and certain neurological diseases. Well it may be effective in those cases it may not be the cure all it was once thought to be for ocular diseases. Read on to learn more.
What is Glaucoma?
First let’s start with the basics and just let you know what glaucoma actually is as outlined by the American Academy of Ophthalmology. Glaucoma is an eye condition in which the optic nerve becomes damaged over time, first reducing peripheral vision then further damaging the optic nerve possibly leading to total blindness. One cause of optic nerve damage in glaucoma is higher-than-normal eye pressure (intraocular pressure or IOP).
What is the Connection between Glaucoma and Marijuana?
In the 1970’s and 1980’s, research showed a measurable decrease in intraocular pressure for three or four hours after smoking cannabis or ingesting THC as a pill or injection. Controlling eye pressure is necessary in glaucoma patients in order to prevent irreversible damage to sight. The one thing the studies failed to take into account or the public simply wasn’t aware of was that in order to treat glaucoma and prevent vision loss, the pressure of the eye has to be controlled 24 hours a day.
Does Cannabis work for Glaucoma treatment?
Cannabis and CBD are not an adequate treatment for glaucoma, or any eye condition. The American Academy of Ophthalmology states that: “they do not recommend marijuana or other cannabis products for the treatment of glaucoma and that the American Glaucoma Society and the Canadian Ophthalmological Society agree.”
To treat glaucoma, eye pressure must be managed 24 hours a day. To maintain the necessary reduction to prevent vision loss it would take roughly 18-20 mg of THC six to eight times a day! That’s a lot of marijuana, even for someone that may partake recreationally. The effect on lifestyle such as the inability to drive, or participate in daily activities effectively would be significant and the benefits would not outweigh the risks of such heavy use. In addition, the cost of using marijuana every three to four hours, every day makes it cost-prohibitive for most patients.
You may be taking a risk by using Marijuana if you have Glaucoma
Increasing evidence shows reduced blood flow to the optic nerve may also cause damage in glaucoma patients with glaucoma. Since marijuana lowers blood pressure throughout the body, it may potentially decrease blood flow to the optic nerve, cancelling out any benefits of lowered intraocular pressure.
What is the difference between CBD and Marijuana?
CBD is a derivative of cannabis that doesn’t have any THC in it. THC is the chemical responsible for the mood-altering effects of the drug, or the “high.”
What about CBD and Glaucoma?
Though widely used to treat other medical conditions there isn’t any research− according to the American Academy of Ophthalmology− to prove it is an effective treatment for glaucoma. They maintain that a recent study proved the opposite as CBD may actually increase IOP.
What is the best treatment for Glaucoma?
According to the Glaucoma Foundation, glaucoma can be treated with eye drops, pills, laser surgery, traditional surgery or a combination of these methods. The goal of any treatment is to prevent loss of vision, as vision loss from glaucoma is irreversible. The good news is that glaucoma can be managed if detected early, and that with medical and/or surgical treatment, most people with glaucoma will not lose their sight.
To sum it all up
Marijuana and compounds derived from marijuana – like CBD – are not an adequate treatment for glaucoma, or any eye condition. To treat glaucoma, eye pressure must be managed 24 hours a day. Marijuana is not a practical treatment for constant use and research is still needed into the exact effects of cannabis and cannabis compounds on eye pressure and glaucoma.
If the effects of cannabis compounds can be isolated, made to be long-acting, and the side effects eliminated, they may lead to new treatments in the future but for now it is best to avoid it completely if you have glaucoma.
A comprehensive dilated eye exam can reveal more risk factors, such as high eye pressure, thinness of the cornea, and abnormal optic nerve anatomy. In some people with certain combinations of these high-risk factors, prescription eye-drops can cut your risk of developing glaucoma in half.
Be sure to get a regular eye exam to see what your risk factors are of developing the disease. If you already have the disease, and are struggling with your current medication or course of treatment, ask us, your trusted Toronto optometrists for advice, before embarking on a new treatment regimen.