Glaucoma refers to a group of eye conditions that damage the optic nerve, usually due to increased pressure inside the eye, known as intraocular eye pressure (IOP). If left untreated, this increase in pressure can lead to vision loss or blindness. Symptoms include blurred vision, severe eye pain, and seeing halos around lights.
As of 2022, approximately 4.22 million people in the U.S. have glaucoma, and 1.49 million people with glaucoma have had their vision affected. Scientists have been exploring cannabis as a potential glaucoma treatment, particularly for its ability to reduce intraocular pressure.
Research on cannabis for glaucoma
Studies show that cannabis may help temporarily reduce intraocular pressure. Particularly, research from the 1970s showed that tetrahydrocannabinol (THC), the primary cannabinoid in cannabis, can reduce intraocular eye pressure by between 25% to 30%.
Recent studies have explored the effects of both THC and cannabidiol (CBD) on glaucoma. While THC appears to be more effective at lowering IOP, it may not be ideal for long-term use due to its psychoactive effects, its short duration of effectiveness, and its potential to decrease function of the retina.
CBD does not show the same impact on IOP, and may actually increase it, according to some studies. However, low doses of CBD may help with other problems that can arise due to glaucoma, like anxiety and insomnia.
Researchers are hopeful about cannabis’s role in managing glaucoma, but more studies are needed to understand its full potential, as well as the best dosing methods.
Using cannabis for glaucoma
Cannabis may reduce intraocular pressure and alleviate related symptoms like pain. However, it’s not a first-line treatment. Before taking it, you should consider potential side effects and drug interactions.
Traditional therapies like medicated eye drops and surgery are more effective forms of long-term glaucoma management. Still, some people may opt for cannabis, especially if they experience side effects from conventional treatments.
Benefits
The potential benefits of using cannabis for glaucoma include:
- Reduced intraocular pressure: THC can lower IOP, which may help protect the optic nerve.
- Relieves pain: Cannabis can alleviate eye pain associated with glaucoma.
- Neuroprotection: THC may improve blood flow to the eye and protect the eye from further damage
Risks and side effects
As with any medication, medical cannabis has some risks and side effects.
- Short duration: The IOP-lowering effects of cannabis last only a few hours, requiring frequent dosing, which may increase the chance of cannabis use disorder (CUD).
- Psychoactive effects: THC can cause dizziness, euphoria, and anxiety, especially in high doses.
- Potential for increased heart rate: Cannabis can raise heart rate in the short term, which may not be suitable for some people with glaucoma.
- Smoke: Cannabis smoke may irritate the eyes. If you prefer to inhale cannabis, vaporization is ideal.
Is it legal?
The legal status of cannabis for glaucoma depends on where you live. Medical cannabis is legal in many states, and glaucoma is a qualifying condition if you live in:
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- District of Columbia (Washington, D.C.)
- Florida
- Guam
- Hawaii
- Illinois
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Dakota
- Northern Mariana Islands
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Puerto Rico
- Rhode Island
- U.S. Virgin Islands
- Vermont
- Washington
The Food and Drug Administration (FDA) has not approved cannabis as a treatment for glaucoma, although an FDA-approved synthetic form of THC called dronabinol has been shown to lower IOP. Always check your local laws before using cannabis.
More about glaucoma
Glaucoma is an eye condition that causes increased pressure inside the eye (ocular hypertension) or poor blood flow to the optic nerve. If left untreated, glaucoma can progress into blindness.
When diagnosing glaucoma, a doctor will measure your intraocular pressure, examine the optic nerve for damage, and assess your vision.
While there is no cure, early detection and treatment can slow down progression and potentially prevent vision loss. Your body’s endocannabinoid system (ECS) may play a role in regulating IOP, which is why cannabis, which interacts with the ECS, could be a potential therapy.
Age, family history, and some conditions and medications can increase the likelihood of glaucoma. Black, Asian, and Latino ethnic groups, as well as those above the age of 40 and people with diabetes, are more likely to develop glaucoma.
Other treatments for glaucoma
Treatment for glaucoma focuses on reducing IOP to slow or prevent optic nerve damage.
Traditional therapies
There are several effective medications and treatments for glaucoma.
- Eye drops: Medications like prostaglandins and beta-blockers reduce IOP.
- Laser therapy: Procedures like trabeculoplasty help improve fluid drainage in the eye.
- Surgery: In severe cases, surgical procedures may be necessary, including trabeculectomy (creating a new pathway for fluid to drain from the eye).
Natural and alternative therapies
Lifestyle changes can be combined with traditional therapies for improved outcomes.
- Changes to diet: Foods rich in antioxidants, like leafy greens, may support overall eye health.
- Exercise: Regular physical activity can lower IOP.
- Herbal supplements: Some people use Ginkgo biloba or bilberry, though evidence of their effectiveness is limited.
Cannabis as part of your treatment plan for glaucoma
Cannabis is not a substitute for traditional therapies, as its effects are short-lived. However, it can be a helpful addition to your glaucoma treatment plan, particularly for managing symptoms like pain and pressure, and if you’re struggling to find relief with conventional treatments.
If you’re considering cannabis, consult with a healthcare provider to determine if it’s right for you. Many states include glaucoma as a qualifying condition for medical cannabis, making it easier to access products legally. To obtain a medical card for glaucoma in your state, contact Leafwell to speak with one of our healthcare providers.
Frequently asked questions
Here are some commonly asked questions about medical cannabis for glaucoma.
Is marijuana bad for glaucoma?
Cannabis, and in particular THC, can actually ease glaucoma symptoms by lowering intraocular pressure and alleviating pain.
Can I get a medical card if I have glaucoma?
Yes. In many states, glaucoma is a qualifying condition for a medical cannabis card. Check your local laws for more information.
Is CBD effective for glaucoma?
Research about CBD and eye pressure is still ongoing. CBD alone may not be as effective as THC for reducing intraocular pressure, and may increase eye pressure. However, it may provide anti-inflammatory and neuroprotective benefits.
Can CBD be used without THC for glaucoma?
CBD can be used without THC, but it may not significantly lower intraocular pressure. Research shows that THC is better for reducing eye pressure, and CBD may increase eye pressure. It’s best to consult with a healthcare provider for guidance.
Which cannabinoid is best for glaucoma?
THC has shown the most effectiveness against glaucoma, although other cannabinoids in cannabis, including CBD, might relieve glaucoma pain and discomfort.
Does smoking make glaucoma worse?
It might. Whenever you smoke, there’s a risk of eye irritation. There’s limited research on whether or not cannabis smoke actually damages the eyes; it’s best to err on the side of caution. Vaporizers or tinctures are best for managing glaucoma symptoms.
