How Does Cannabis Help Glaucoma?

• Glaucoma is an eye disorder caused by increased intraocular pressure (IOP). Glaucoma can occur in people with unique eye anatomies and other high-risk populations.
• While there is some clinical evidence showing that THC can lower IOP, there is less data supporting CBD as an IOP reducer. However, patients report using cannabis for glaucoma with success.
• To determine whether or not cannabis might be the right treatment for your glaucoma, talk to a cannabis-informed healthcare provider.

If you’re living with glaucoma, you might be wondering if medical cannabis could offer the relief you’re looking for. Since it helps reduce chronic pain (with a variety of underlying causes) and supports people with countless other health conditions, it stands to reason that medical marijuana might be a viable treatment for glaucoma, right?

Patients should consider two things as they assess the potential of medical marijuana for glaucoma treatment:

1. Clinical evidence for THC and CBD in glaucoma relief is limited, but promising.
2. Anecdotal reports make it clear that glaucoma patients are already benefiting from medical cannabis treatment.

As usual, there’s a lot to unpack here—and that’s exactly what this guide aims to do. Below, we’ll shed some light on glaucoma, THC, and CBD as therapeutics for glaucoma, and a few considerations to make before committing to medical cannabis treatment.

What Is Glaucoma?

Glaucoma is an eye condition that (among other effects) can cause blindness over time.

In people without glaucoma, the eyes constantly balance the production and drainage of aqueous humor: a liquid found throughout the inside of your eyes. As new aqueous humor is made, the eye drains out the same volume, maintaining homeostasis.

People living with glaucoma, however, don’t drain aqueous humor at the same rate that they produce it; this buildup of fluid can increase intraocular pressure (IOP), causing pain and discomfort (along with other symptoms and long-term effects).

Causes of Glaucoma

There are two types of glaucoma, each with a distinct cause:

• Open-angle glaucoma occurs when the drainage angles in the eyes (which drain aqueous humor) progressively decrease their drainage output. Experts often compare this to a clogged drain—there are many possible causes, but at the end of the day, the result is the same.
• Closed-angle glaucoma (or angle-closure glaucoma) happens in people with a distinct anatomical issue: their iris is too close to the drainage angle, preventing normal drainage. This type of glaucoma can lead to acute attacks—when the iris slides completely over the drainage angle, IOP quickly increases.

Symptoms of Glaucoma

Open-angle glaucoma is particularly insidious (often called “the silent thief of sight”) because patients typically don’t notice any symptoms until they start to lose their vision. If open-angle glaucoma goes undetected (and, thus, untreated), patients may develop pain or “blind spots” in their vision over time.

In cases of closed-angle glaucoma, patients usually only notice symptoms during an acute attack.

These can include:

• Headache
• Decreased or blurred vision
• Eye or forehead pain
• Eye redness
• Seeing halos or rainbows

Since glaucoma typically doesn’t present symptoms until the condition becomes severe, getting regular eye exams from an ophthalmologist is paramount—it’s one of the only ways to detect (and treat) glaucoma before it becomes symptomatic.

During an exam, an eye expert:

• Observes the optical nerve for abnormalities
• Takes note of the iris position in relation to the drainage angle in each eye
• Measures changes over time across repeat visits

Glaucoma Outcomes, Risk Profiles, and Conventional Treatments

Over time, severe glaucoma can cause blindness or extensive vision challenges. However, not everyone is at risk of developing glaucoma.

Some high-risk groups include people who:

• Are over 40
• Have relatives with glaucoma (i.e., are genetically predisposed)
• Are of African, Latinx, or Asian descent
• Have vision problems (e.g., shortsightedness, farsightedness, astigmatism)
• Have past eye injuries
• Have taken steroids long-term
• Have thin optic nerves or corneas
• Have diabetes, migraines, high blood pressure, or other systemic (i.e., whole-body) health issues

In terms of treatment, patients have two options: prescription eye drops designed to decrease IOP and corrective surgeries.

These laser surgery procedures include:

• Trabeculoplasty – In a trabeculoplasty, an ocular surgeon uses a laser to clear blockages in the drainage angle, increasing aqueous humor drainage and decreasing IOP. This is primarily designed for patients with open-angle glaucoma.
• Iridotomy – In iridotomies, surgeons use a laser to create a small hole in the iris to create an alternate path to the drainage angle. This improves drainage and decreases IOP. This method is mostly used for people with closed-angle glaucoma.

Cannabinoids and IOP

Where do cannabinoids come in? The primary goal of glaucoma treatments is to decrease IOP—so, can cannabis do that? Let’s dive into both of the major cannabinoids and what we currently know.

THC Can Lower IOP

Clinical evidence that THC can decrease IOP is long-standing—two scientists in 1971 published data demonstrating that glaucoma patients who smoked weed saw a 25% decrease in IOP after dosing. These results have been replicated in numerous clinical studies via multiple marijuana administration methods, including:

• Sublingual drops
• Intravenous (IV)
• Capsules
• Topicals (in the form of eye drops)

While researchers aren’t yet sure exactly how THC relieves IOP, they have widely identified endocannabinoid system (ECS) receptors (both CB1 and CB2) in multiple areas of the eye: the iris, multiple retinal layers, and parts of the cornea, among others. This means that cannabinoids introduced via cannabis consumption can bind to or interact with the ECS inside the eye itself—an exciting proposition for researchers and glaucoma patients alike.

CBD Might Lower IOP

Unfortunately, research into CBD’s effects on IOP hasn’t been as widely studied as THC’s impacts. One of the only studies to date (from almost 20 years ago) only noticed a slight decrease in IOP when using a high dose of CBD.

However, this study has two key limitations:

1. It was small—the sample size only included six glaucoma patients.
2. Researchers only tested sublingual administration.

Clearly, more research needs to be done to understand the full scope of CBD’s impact on IOP and glaucoma. However, in the case of both THC and CBD, anecdotal evidence is clear: many patients are already using medical cannabis for glaucoma relief with great success.

Considerations for Glaucoma Patients

If you’re ready to try medical cannabis for glaucoma relief, there are two things to consider before you look into pursuing your medical marijuana card:

Dose Longevity

While you can customize your dosage routine to maintain the effects of cannabis for multiple hours, marijuana does eventually wear off—whether you use products containing THC, CBD, or both.

So, you should only expect to feel relief from glaucoma symptoms while cannabis is actively working inside your system. Effects can last from two to five hours (on average).

This is one of the main reasons why Western medical providers typically don’t recommend cannabis as a glaucoma treatment—in their view, 24/7 cannabis use isn’t feasible or practical. But there are two counterclaims to remember:

• Not all cannabis is psychoactive – THC is the only psychoactive compound found in marijuana; you can completely avoid a high by choosing products with 10% or lower THC concentration (opting for high-CBD products instead). CBD doesn’t impede executive, motor, or cognitive functions, and many patients report that it relieves their glaucoma symptoms.
• Cannabis doesn’t have to be smoked – While smoking and vaping aren’t very subtle administration methods, patients have other choices: taking capsules, eating edible products, or using sublingual drops, for instance. These are all low-odor, discreet dosing methods that can help you maintain stasis throughout the day.

Cannabis as a Complementary Treatment

While medical cannabis offers promising results for people living with glaucoma, it isn’t the only option—in fact, you might choose to combine cannabis products with traditional treatments (like prescription eye drops or surgical corrections) for optimal relief.

There’s no one-size-fits-all treatment option for everyone. Feel free to experiment with medical cannabis or use it as a complement to a treatment that already offers some relief.

Start Your Medical Cannabis Journey with TeleLeaf

For many patients, medical marijuana offers tangible relief from glaucoma symptoms—even if clinical data is still limited.

To get started with medical cannabis, you’ll need a medical card: that’s where TeleLeaf comes in.

Our network of licensed, cannabis-informed providers will meet with you, discuss your healthcare concerns, and help you create a medical marijuana treatment regimen that meets your needs. But they won’t just help you apply for your medical card: they’re here to help you tweak your routine and provide support throughout your cannabis treatment journey.

Ready to discover all-natural, plant-based glaucoma relief? Reach out to TeleLeaf to get started.

Sources: 

American Academy of Ophthalmology. What Is Glaucoma? Symptoms, Causes, Diagnosis, Treatment.
https://www.aao.org/eye-health/diseases/what-is-glaucoma

National Library of Medicine. Cannabis Use for Glaucoma and Associated Pain.
https://www.ncbi.nlm.nih.gov/books/NBK572112/

Journal of Glaucoma. Effect of Sublingual Application of Cannabinoids on Intraocular Pressure: A Pilot Study.
https://pubmed.ncbi.nlm.nih.gov/16988594/