Glaucoma and Marijuana
An Honest Look at Glaucoma and Marijuana
Do glaucoma and marijuana go together? Marijuana is a natural product, so is it better than prescription glaucoma treatments? The Oregon Eye Specialists physicians are well qualified to answer this question. Medical marijuana use is legal in Oregon, recreational use is legal in Washington State to our north and starting July 1, Oregonians will be allowed to possess and grow small amounts of marijuana for personal use.
So should you switch from glaucoma drops to marijuana? This post answers common questions about glaucoma and cannabis use.
Is it true that marijuana is an effective glaucoma treatment?
High eye pressure – what doctors call “intraocular pressure” – can cause damage to the optic nerve. Marijuana use lowers intraocular pressure for a few hours.
However, what actually causes blindness in glaucoma is damage to the optic nerve, which connects the eye to the brain. Each eye only has one, so it is important to protect it. Because marijuana lowers blood pressure as well as intraocular pressure, it can reduce the optic nerve’s blood supply—and if you have glaucoma, that nerve has already suffered some damage. Lowering the blood supply may not be beneficial.
How does marijuana affect glaucoma?
Studies in the 1970s showed that marijuana can lower intraocular pressure for three to four hours. When someone tells you research shows marijuana is effective for treating glaucoma, they may be referring to these studies.
What dose of marijuana lowers eye pressure?
Researchers from studies in the 1970s found that smoking a marijuana cigarette lowered eye pressure for three to four hours. (Because marijuana is a natural product manufactured in many different ways, it’s not possible to know the exact amount of tetrahydracannabinol, or THC—the active ingredient—in a cigarette, edible product or other “dose” of marijuana.)
If you have glaucoma, it is important to lower your eye pressure 24 hours a day. Researchers estimate you would need to smoke a marijuana cigarette eight to 10 times daily to achieve this, while you only need to use traditional glaucoma eye drops once or twice daily.
Marijuana is natural, so it doesn’t have dangerous side effects … right?
Smoking or eating marijuana products gives the same side effects in medical as recreational use. Some of these effects, such as feeling high or being dizzy or less coordinated, can be dangerous no matter why you use marijuana—for example, driving while high is just as dangerous as driving drunk.
Doctors are also concerned because most patients with glaucoma are over 60. Older adults may have a higher risk of falling, so feeling dizzy or uncoordinated is especially risky. Heart problems are more common in this age group, and marijuana is known to increase heart rate. Other potentially risky side effects include:
- Weaker immune system—Less ability to fight off infections
- Problems with memory, thinking and concentration
- Changes in the lungs, if smoked
- Eye damage—Smoking is a leading factor in age-related macular degeneration, which can cause significant vision loss and blindness. It is also a risk factor for cataracts.
Marijuana does lower eye pressure. Why don’t eye doctors prescribe it?
Today, there are many more effective glaucoma treatments available than in the 1970s. The main glaucoma treatments today are:
- Eye drops that contain pressure-lowering medicines, alone or in combination (combinations are sometimes more effective)
- Laser treatment
- Microsurgery—If drops and laser treatment do not work
Repeated, carefully conducted scientific trials have proven these treatments effectively delay glaucoma progression, which leads to blindness if untreated. However, no studies have compared marijuana with glaucoma drops or other treatments. Doctors have strong evidence that current treatments work, and there are many to choose from. They do not have similar evidence for marijuana and glaucoma.
Glaucoma drops are expensive – I can’t afford them.
Some glaucoma drops are relatively expensive, but others are not. If cost is a factor in buying your glaucoma medication or taking it as often as prescribed, don’t hesitate to talk with your doctor. We can prescribe a different type of medication or a generic version may be available.
What should I do for my glaucoma?
The best thing you can do to prevent glaucoma is get a regular general eye exam.
- Learn how often to get an eye exam
- Read another post, Nine Signs You Could Have the Silent Thief of Sight
- Read complete information on glaucoma diagnosis, treatment and prevention
Where can I learn more about glaucoma and marijuana?
Interested in learning more? Here are some medical sources we recommend.
- American Academy of Ophthalmology, “Marijuana in the Treatment of Glaucoma”
- Glaucoma Research Foundation, “Should You Be Smoking Marijuana to Treat Your Glaucoma?”
Questions about glaucoma treatment?
If you are concerned about glaucoma or struggling with your current treatment, we hope you always feel free to contact Oregon Eye Specialists. Our experienced physicians welcome your questions and will work with you to find an effective, affordable treatment.
Learn more about Glaucoma and marijuana