How Does Marijuana Help Glaucoma?

Glaucoma treatment is one of the more famous uses for medical marijuana, all thanks to the story of one man: Robert Randall. In the 1970s, 26-year-old Randall discovered that using marijuana made some of the symptoms of his advanced glaucoma disappear. Randall began using marijuana to control his glaucoma but ended up facing federal criminal charges for the possession of marijuana. Yet, Randall won his case in a landmark ruling after successfully arguing that using marijuana to treat his glaucoma was a medical necessity. Randall’s story— and his historical legal win— garnered an incredible amount of media attention at the time and, ever since, the idea that marijuana can treat glaucoma has been in the public consciousness.

So, how did marijuana help Robert Randall treat his glaucoma? Can marijuana really help glaucoma and does anyone use it to treat glaucoma today? Below, we’re answering these questions and more as we go over everything you need to know about the connection between marijuana and glaucoma. We’ll talk about what glaucoma is, what treats it, and whether or not marijuana can help glaucoma patients.

What is Glaucoma?

Glaucoma is a disease that causes damage to the optic nerve, which is a vital part of eyesight. Glaucoma usually occurs due to fluid build up in the front part of the eye. When fluid builds up in the eye, it increases pressure within the eye, damaging the optic nerve.

There are two main types of glaucoma: primary open-angle glaucoma and angle-closure glaucoma. Primary open-angle glaucoma is the most common type of glaucoma. It happens when the eye doesn’t drain fluid effectively and gradually causes a build up in pressure over time. Angle-closure glaucoma happens when someone’s eye drainage angle becomes completely blocked, which causes a rapid rise in eye pressure.

What are the Symptoms of Glaucoma?

The most common symptom of glaucoma, increased eye pressure, isn’t necessarily something a person will notice. It’s also easy to miss risk factors that are associated with glaucoma. People are highly unlikely to notice certain glaucoma risk factors, like having corneas that are thin in the center, on their own. Many people also don’t know that some common conditions, like high blood pressure and extreme nearsightedness or farsightedness, are risk factors for glaucoma. That’s why doctors recommend getting regular eye health screenings to help your optometrist or ophthalmologist detect glaucoma before vision loss occurs.

The first noticeable symptom of the most common type of glaucoma, primary open-angle glaucoma, is usually peripheral vision loss. This vision loss can occur so gradually that people don’t notice it until it becomes severe. Angle-closure glaucoma, on the other hand, has a sudden onset of symptoms. Once a person’s eye drainage angle becomes fully blocked, they may experience symptoms such as severe pain in the eye or forehead, eye redness, blurred vision, decreased vision, headache, nausea, vomiting, and seeing rainbows or halos. An angle-closure glaucoma attack is considered an emergency that must be treated right away in order to avoid permanent optic nerve damage.

Does Glaucoma Cause Blindness?

Glaucoma will eventually lead to blindness if it goes untreated. It’s the top cause of blindness in people aged 60 or older, making it more common than blindness caused by cataracts, diabetic retinopathy, and age-related macular degeneration.

While glaucoma causes blindness when it is left untreated, it doesn’t have to lead to complete vision loss. There are treatments that can usually manage glaucoma and prevent further vision loss.

How Is Glaucoma Treated?

According to the American Academy of Ophthalmology, “the only way to control glaucoma and prevent vision loss is to lower the pressure in your eye.” Some standard ways an ophthalmologist may treat glaucoma include glaucoma medication, such as prescription eye drops, and surgery. The AAO states that the right treatment for each patient can vary “depending on the type of glaucoma and how severe it is.”

What is the Connection Between Marijuana and Glaucoma?

The idea of using marijuana to treat glaucoma became widespread in the 1970s due to media coverage of Robert Randall’s usage, which was likely influenced by a recent study that was published in the Journal of the American Medical Association. This 1971 study looked at how marijuana affected eye pressure. Participants were given eye exams an hour before and an hour after they smoked a marijuana cigarette. The study found that the participants experienced a 30 percent decrease in eye pressure after using marijuana.

Because glaucoma is controlled by lowering the pressure in the eye and the 1971 study suggested marijuana could do just that, some may say that marijuana can effectively treat glaucoma. But can it? Well, answering that question is complicated because we don’t have a bevy of recent studies on marijuana as a glaucoma treatment to turn to for evidence. This treatment method hasn’t been well-studied in recent years and has not been compared to traditional glaucoma treatments in clinical trials.

There have been a few notable studies over the last fifty years, including ones in 1981, 1999, and 2006. The 1981 study found that eyedrops containing tetrahydrocannabinol (THC) did not affect intraocular pressure (IOP), likely because the THC could not be well-absorbed into the eyes. The 1999 study found that smoking marijuana reduced IOP for around 3 hours. And the 2006 study found that a sublingual dose of THC lowered IOP for around four hours, but a sublingual dose of cannabidiol (CBD) did not lower IOP.

Potential Challenges of Marijuana for Treating Glaucoma

The research on using marijuana to treat glaucoma suggests that the treatment method could pose some challenges, one of which would be psychoactive side effects. Based on the limited research we have available on the topic, it appears that the psychoactive cannabinoid THC plays a major role in marijuana’s ability to lower intraocular pressure, while the non-psychoactive cannabinoid CBD doesn’t seem to lower intraocular pressure. It also appears that topical applications of THC, which do not cause psychoactive effects, aren’t effective at lowering intraocular pressure. Essentially, this means that psychoactive effects probably go hand-in-hand with using marijuana for the treatment of glaucoma. While this may not be a problem for some patients, other patients (especially elderly patients) may not want to experience the psychoactive effects associated with this active ingredient.

Another potential challenge of using marijuana to treat glaucoma is dosage. Research shows that smoking cannabis only lowers intraocular pressure for a few hours, so a glaucoma patient would need to smoke around 6 to 8 times a day to treat their eye condition. Some may not like the frequency needed with this dosage and others may not be able to tolerate consuming THC so regularly. Then, consuming edible cannabis products provides a longer duration of action compared to smoking, but the absorption of these types of products can be unpredictable and can vary significantly from person to person. This can make accurately dosing edibles for glaucoma challenging, which makes it harder to control for the potential side effects of marijuana, like lowered blood pressure or nausea.

Lastly, it’s important to point out that a major challenge of using marijuana to treat glaucoma is that we just don’t have enough research on the topic. There may be ways to use marijuana or cannabinoid-derived medications to treat glaucoma effectively, but we need many more studies to know for sure.

Potential Benefits of Marijuana for Treating Glaucoma

While there are some effective traditional glaucoma treatments, those traditional treatments don’t work for everyone. Some people have treatment-resistant glaucoma, while others find it hard to tolerate traditional treatment methods due to unpleasant side effects. In cases like these, patients may end up having to try alternative treatment methods. And, anecdotally, some people say that using cannabis (alone or alongside other treatments) has made an enormous difference in their glaucoma symptoms.

Final Thoughts On Using Marijuana for Glaucoma

While there’s some evidence that using marijuana can lower intraocular eye pressure, we need more evidence to understand how marijuana affects glaucoma when used as a long-term treatment. The research on using cannabis to treat glaucoma is just very limited at the moment, so ophthalmologists generally recommend that patients use more traditional methods of treating glaucoma, since those are well-studied.

For now, the best thing for glaucoma patients to do is to follow the recommendation of their doctor. Glaucoma is a progressive condition that can lead to vision loss and blindness when untreated, so it’s not a good idea to try to come up with your own treatment plan for this condition. If you want to try using marijuana for glaucoma or use marijuana alongside a traditional glaucoma treatment, talk to your doctor about your treatment options.