Glaucoma, Marijuana & CBD: Facts & Myths
Table of Contents
- The Search for Lower Intraocular Pressure
- Can Medical Marijuana or CBD Help Glaucoma Symptoms?
- The Science of Marijuana’s Impact on Glaucoma
- Medical Studies
- Eye Doctors Understand
Glaucoma involves high intraocular pressure and damage to the optic nerve. The most common type of glaucoma, open-angle, is a chronic and progressive disease that can be tough to manage. As medical marijuana becomes more popular, more people are interested in the suggestion that marijuana or CBD oil can help this eye condition. (Learn More)
Medical professionals agree that no form of medical marijuana, especially CBD products, helps to manage glaucoma symptoms. In fact, some types of medical marijuana can make symptoms worse and cause further eye damage. (Learn More)
The few medical studies conducted on marijuana and intraocular pressure found that THC, not CBD, temporarily lowers IOP. But this result does not last long enough to make it a good medical treatment. And marijuana can be addictive. (Learn More)
Further medical studies have shown that CBD in medical marijuana can slightly raise intraocular pressure, and marijuana decreases blood flow. Both of these things can further damage the optic nerve. (Learn More)
The best way to treat glaucoma is to follow your eye doctor’s treatment plan. (Learn More)
Glaucoma & Marijuana: The Search for Lower Intraocular Pressure
The term glaucoma covers several eye diseases that involve high fluid pressure and damage to the ocular nerve, leading to vision loss.
Open-angle glaucoma is the most common type. This is a progressive, chronic disease that leads to tunnel vision and eventual blindness if it is not treated. Other types of glaucoma may develop suddenly, and some even constitute a medical emergency and require immediate surgery.
Most people who develop glaucoma will not notice symptoms. An optometrist or ophthalmologist will diagnose high fluid pressure during your regular eye exam and conduct further tests to measure any potential vision loss. Then, your eye doctor will recommend medical treatment like eye drops or surgery to reduce your vision loss. While you cannot recover lost vision, you can slow the progression of open-angle glaucoma.
Eye specialists continually search for better treatments to slow the progression of chronic forms of glaucoma. The first study examining marijuana’s impact on glaucoma occurred in 1971. It found a 30 percent overall decrease in eye pressure among participants who smoked a marijuana cigarette an hour before undergoing an eye exam.
Since then, this and related studies have been used to promote now-legal medical marijuana like cannabidiol (CBD) to treat glaucoma. However, this treatment is not recommended by medical professionals.
Can Medical Marijuana or CBD Help Glaucoma Symptoms?
Medical professionals agree that marijuana, including CBD, is not an effective treatment for glaucoma. This means that, even if medical marijuana is legal in your state, your optometrist or ophthalmologist will not prescribe it as a medical treatment for this condition.
First, glaucoma must be managed 24 hours a day, and no form of marijuana is a practical treatment for ongoing management of any condition. The drug’s effects only last a few hours, while many chronic conditions require medication that lasts at least half the day.
Additionally, there is little medical research into how marijuana affects glaucoma. The research that does exist suggests that the drug does not help eye pressure for long, and it can be detrimental to the condition over time.
Finally, it is well known that marijuana is an addictive substance. While it may not be more harmful than alcohol, it is a drug that causes intoxication, impaired judgment, and changes in brain chemistry and structure that impact the rest of your life.
The Science of Marijuana’s Impact on Glaucoma
While there were some studies in the 1970s and 1980s that found marijuana could lower intraocular pressure, the real association between the drug and glaucoma treatment occurred due to a landmark medical marijuana court case in 1974.
A man named Robert Randall, who was 26 years old with high intraocular pressure and poorly treated glaucoma (unusual for his age) reported that the halos he saw around lights, which were a symptom of his eye condition, decreased when he smoked marijuana. He began to grow his own pot so he would have access to “medicine” that seemed to work for him. Soon, he faced federal criminal charges for growing the illegal plant, but he was able to persuade the federal judge that he needed marijuana as a medical treatment.
California became the first state to legalize marijuana in any form, in 1996. Glaucoma treatment was cited as one of the potential conditions that medical marijuana could help.
Although CBD has more recently been associated with medical marijuana, the chemical that works on intraocular pressure is tetrahydrocannabinol (THC). This chemical has been shown to lower intraocular pressure by 60 to 65 percent in anyone, including people who have glaucoma. One study found that, over the course of marijuana’s primary effects on the body, IOP lowered 25 percent overall. This could seem to help glaucoma patients, but it is not a long-term solution due how THC is metabolized.
THC’s peak effects in the body last for three to four hours. For any medical marijuana treatment to be effective for glaucoma, you would need to take a dose several times a day. Not only is this disruptive to work, school, or a regular daily routine, it also means you will be consistently intoxicated, which can be very dangerous. Marijuana, especially types high in THC, is addictive.
Short-term effects of marijuana include:
- Altered senses, like seeing brighter colors.
- Altered sense of time.
- Changes in mood.
- Impaired body movement.
- Difficulty thinking clearly.
- Problems with memory.
- Trouble solving problems.
- Hallucinations, delusions, and even psychosis, when used at very high doses.
- Paranoia or anxiety.
When used on a long-term basis, marijuana changes your brain’s development and alters structures in the brain associated with the reward system. Some medical studies have found that consistent, long-term abuse of this drug lowers intelligence and cognitive abilities, leads to a significant decline in general knowledge, and can lead to memory problems.
Mood problems can also arise. You may become more anxious or aggressive when you are not intoxicated.
Additionally, marijuana has been associated with eye problems, including:
- Conjunctival hyperemia (discharge from the eye).
- Less tear production.
- Light sensitivity.
- Ptosis, or drooping eyelid.
- Blepharospasm, or uncontrolled twitching eyelid.
- Nystagmus, or shaking eyes.
Medical Studies Show That Alternate Forms of Marijuana Can Cause Harm to the Eyes
Today, there are new methods of ingesting medical cannabis that could be less addictive. For example, lozenges, topical oils, and creams have all been developed to reduce the risk of getting high while benefitting from potential medical effects.
Unfortunately, these newer methods of medical marijuana use do not work to lower intraocular pressure. A study found that eye drops containing THC did not lower intraocular pressure at all. Another study found that smoking marijuana lowered intraocular pressure, and the amount of cannabis ingested would lower IOP in measurable ways, but ingesting more cannabis would not lead to effects that lasted longer. The body still metabolized THC’s peak effects in three to four hours.
Because the effects on IOP last only a few hours, medical marijuana does not help to maintain stable low eye pressure, which is necessary to reduce damage to the optic nerve.
Some studies suggest that marijuana can increase optic nerve damage. Cannabis use decreases blood flow throughout the body. If the optic nerve does not receive enough oxygen through the bloodstream, it will begin to die, which will lead to further vision loss.
A study on CBD oil in laboratory rats found that there was a paradoxical harmful effect. Since THC seems to be the chemical that lowers IOP, using medical marijuana with less THC can be worse for your eyes. The study reported an 18 percent increase in intraocular pressure in the rats who used CBD oil, which lasted for about four hours.
Eye Doctors Understand the Best Course of Glaucoma Treatment
Ultimately, the best treatment for glaucoma keeps eye pressure in a healthy range all day. Eye drops and some forms of surgery can help to maintain lower eye pressure for months or years. Eye drops must be applied consistently, but they will be used less often than medical marijuana would need to be used, and they have fewer impactful side effects.
Glaucoma. (July 2019). National Eye Institute (NEI).
What Is Marijuana? (September 2019). National Institute on Drug Abuse (NIDA).
CBD Oil May Worsen Glaucoma. (February 2019). American Academy of Ophthalmology (AAO).
- Surgery & Cost Info
- Glaucoma Laser Surgery
- What Is iStent for Glaucoma?
- Types, Timelines & Treatments
- Timelines & Prevention
- Open-Angle Glaucoma
- Narrow Angle
- Glaucoma Medications
- Modern Treatment Options
- Pigmentary Glaucoma
- Can it Be Prevented?
- Acute vs. Chronic
- How to Spot the Early Signs
- Exfoliation Glaucoma
Every NVISION® patient is unique. To determine the best treatment for you, please complete our simple form to schedule a consultation exam.People who have glaucoma often wonder if there are better forms of treatment than eye drops or surgery. This led to an interest in marijuana, including the use of CBD. Learn what studies say about the effect of marijuana use on glaucoma.
CBD Oil for Glaucoma
According to the Glaucoma Research Foundation, there are an estimated three million people in America suffering from Glaucoma, and half of them aren’t even aware of their issue. It’s one of the leading causes of blindness in the US; 10% of patients with this condition experience vision loss – even if they get the proper treatment.
So, could CBD be the remedy that everyone has been waiting for? CBD, a component of marijuana, is being increasingly hailed as an alternative treatment for a variety of health issues. Not that long ago, many people believed that CBD oil for glaucoma was a viable treatment option. But unfortunately, in recent times, eye doctors are advising patients not to use CBD as a remedy for glaucoma.
New research suggests that rather than lowering eye pressure, CBD raises it. This is a problem because high eye pressure is the main risk factor for glaucoma. That said, there are some studies that suggest that there are some benefits to using CBD for glaucoma.
Essentially, there’s a lot of conflicting information regarding the use of CBD for glaucoma. In this article, we will take a closer look at Glaucoma and its’ possible treatment options, including CBD eye drops.
What Is Glaucoma?
Glaucoma is a medical ailment that damages the eye’s optic nerve. This is the nerve that transmits visual information to the brain and allows us to see. Often, it’s linked to a buildup of pressure inside the eye and is a condition that gets worse over time. Glaucoma is a leading cause of blindness for people over the age of 60. While it can occur at any age, it’s more common in older adults.
There are a few types of glaucoma; the two most common are primary open-angle glaucoma (POAG) and angle-closure glaucoma (ACG). Open-angle glaucoma is known as the “sneak thief of sight” because it doesn’t present any symptoms until significant vision loss has occurred.
Glaucoma vision damage is a real possibility. Shockingly, glaucoma is the leading cause of irreversible blindness in the world.
What Causes Glaucoma?
One of the main causes of glaucoma is optic nerve damage. As the nerve gradually deteriorates, blind spots start to develop in one’s visual field. For reasons that aren’t fully understood by doctors, this nerve damage is typically related to an increase in eye pressure.
Elevated eye pressure is the result of a buildup in fluid (aqueous humor) that flows all throughout the inside of the eye. Normally, the internal fluid drains out through a tissue known as the trabecular meshwork at the angle where the cornea meets the iris.
When the drainage system doesn’t work properly, or when fluid is overproduced, it’s unable to flow out at its normal rate, and therefore eye pressure increases.
Ultimately, glaucoma is caused by a higher than normal pressure inside the eye, known as ocular hypertension. But, it can occur even when the pressure inside the eye, known as intraocular pressure, or “IOP”, is normal.
Less common causes include severe eye infection, inflammatory conditions, blunt or chemical injury to the eye, and blocked blood vessels inside the eye. Usually, it occurs in both eyes, but it may be worse in one than the other.
Glaucoma often runs in families. In some cases, scientists have identified genes in people related to glaucoma optic nerve damage and high eye pressure. Typically, it affects adults over 40-years, but children, young adults, and even infants can also get it. African Americans tend to get glaucoma more often when they are younger, and they experience more vision loss.
Types of Glaucoma
There are several types of glaucoma. Each type is different, but most don’t have any early symptoms. We will go into a bit more detail on each below:
- Secondary Glaucoma: This is any form of glaucoma in which there’s an identifiable cause of increased eye pressure, one which results in optic nerve damage and vision loss. For instance, cataracts or diabetes. Secondary Glaucoma can be of the angle-closure or open-angle type.
- Pigmentary Glaucoma: A type of secondary open-angle glaucoma, this form occurs when the pigment from the iris flakes off. The loose pigment could block fluid from draining out the eye; this may increase eye pressure and cause Pigmentary Glaucoma.
- Pseudoexfoliative Glaucoma: Also known as Exfoliation Glaucoma, this is a type of Open-angle glaucoma that affects some people with exfoliation syndrome – a condition that causes extra material to become detached from parts of the eye and therefore blocks fluid from draining.
- Traumatic Glaucoma: Any type of glaucoma that is caused by an injury to the eye. It can occur immediately after an injury or years later.
- Neovascular Glaucoma: A type of Secondary Glaucoma that’s generally associated with poor vision prognosis.
- Iridocorneal Endothelial Syndrome (ICE): This is a unique ophthalmic disorder that is linked to an irregular corneal endothelium. It can lead to varying degrees of iris atrophy, corneal edema, and secondary angle-closure glaucoma.
- Uveitic Glaucoma: This form may occur in people who have Uveitis, a condition that causes inflammation (swelling and irritation) in the eye. Approximately 2 in 10 people who have Uveitis will develop Uveitis Glaucoma. Experts aren’t sure why this happens, but they believe it may occur because Uveitis can cause scar tissue and inflammation in the middle of the eye. This may damage the part of the eye where the fluid drains out, thus causing high pressure.
What Is the First Sign of Glaucoma?
Most people who have this condition don’t experience any pain or early signs of glaucoma. The most common form of glaucoma has no warning signs and will only be detected during a comprehensive eye exam. The effect is so gradual that patients often won’t notice a change in their vision until the condition is at an advanced stage.
If undetected and untreated, you will first experience peripheral vision loss and may eventually become blind. By the time you notice any vision loss, it’s too late. The lost vision cannot be restored, and it’s highly likely that you will experience additional vision loss even after treatment begins.
Since vision loss caused by glaucoma can’t be recovered, you should schedule regular eye exams with your eye doctor. They should take measurements of your eye pressure to ensure that a diagnosis can be made in the early stages and treated appropriately.
Ultimately, there are very few, if any, warning signs of glaucoma. But if recognized early, vision loss can be prevented or at least slowed.
Depending on your situation and what type of condition you have, treatment for glaucoma options may include oral medications, eye drops, laser surgery, or microsurgery to lower the pressure in the eye.
Currently, there is no glaucoma cure when it comes to vision loss. Existing treatments can slow the process for most patients to ensure that no meaningful vision loss occurs in their lifetime.
Several types of glaucoma treatment involve surgery to try to fix the issue. But, eye drops are the most commonly prescribed option for open-angle glaucoma. There are a variety of medicated eye drops formulated specifically to treat the condition. These include beta-blockers, cholinergic agents, prostaglandin analogues, and carbonic anhydrase inhibitors.
Typically, these medications work in different ways. For instance, beta-blockers work by decreasing fluid production that leads to increased IOP. Prostaglandin analogues, on the other hand, increase the outflow of fluid from the eye.
So what about CBD and Glaucoma?
CBD Oil for Glaucoma
If you were hoping that CBD oil would offer a natural remedy for glaucoma, the latest research is not good. As we already mentioned, a new study has found that CBD doesn’t lower the eye pressure – instead, it raises it.
As part of the study, researchers from Indiana tested eye drops that contained CBD on rats. They discovered that it raised the pressure inside the eye by 18% for at least four hours after the drops were administered. They also tested THC, and interestingly, the eye drops that only contained THC decreased eye pressure by up to 30% within eight hours.
What does this mean? Well, it seems as though CBD oil and glaucoma may not be the remedy that many had hoped for. However, patients may be able to use marijuana for glaucoma, since THC is a key component of marijuana and has shown promise for its ability to decrease eye pressure.
The problem is that THC is psychoactive, meaning that it makes users high. For this reason, many patients are immediately put off by glaucoma marijuana treatments.
CBD Benefits for Glaucoma
Although CBD oil and glaucoma aren’t the perfect combination, CBD may be able to help in other ways. Many glaucoma patients suffer from unexpected and uncomfortable symptoms such as nausea, vomiting, and severe pain. CBD products contain anti-nausea and analgesic properties, which may help to relieve these symptoms.
In addition, some studies have found that CBD could relieve intraocular pressure in the eye, and thus alleviate symptoms and reduce damages.
Generally, glaucoma harms the eye due to the excessive release of a damaging chemical called glutamate. This leads to the death of neurons in the retinal after peroxynitrite has formed. Some scientific research has claimed that CBD can help to prevent the formation of peroxynitrite. As a result, it provides ultimate protection for the neuron nerves from glutamate-induced cell death.
Final Thoughts on CBD Oil for Glaucoma
There’s no doubt that a lot more research needs to be done on using CBD oil for glaucoma. The latest studies suggest that CBD could worsen the condition rather than treat it. However, some studies have found that CBD products, like CBD eye drops, could be beneficial in relieving several of the symptoms associated with glaucoma.
It’s safe to say that the research out there is conflicting. What we can report is that many patients have reported positive results when using marijuana for glaucoma relief. But this isn’t a viable option for everyone because THC (prominent in marijuana) is intoxicating and makes users high. We hope to see more research in the near future.New research suggests that rather than lowering eye pressure, CBD raises it. but how does this impact glaucoma on the whole? Learn more here. ]]>