how much cbd oil to take for glaucoma

CBD for Glaucoma

Glaucoma is a condition which causes damage to the optic nerves in the eye. This illness happens when there is a fluid building up in the front area of the eye. This fluid increases the pressure and gradually does harm to the optic nerves.

These days, Glaucoma tends to be inherited from generation to generation. It often shows up in people who are 60 years old and above. If the damage continues for a long time, it can result in permanent blindness or partial vision loss. Most patients who are suffering from glaucoma have no early pain or symptoms. It’s important to see an eye doctor frequently so he or she would diagnose before a long-term vision loss occurs.

Signs & Symptoms of Glaucoma

Some common symptoms and signs include a gradual loss of peripheral vision in both eyes, tunnel vision, severe eye pain, blurred vision, vomiting or nausea, red eyes, and unexpected vision issues, especially when lighting is limited.

Risk Factors For Glaucoma

There are some risk factors for developing Glaucoma including:

  • Old age
  • Ethnic background (Hispanics, East Asians, and African Americans have higher risks of developing glaucoma than Caucasians)
  • Hypothyroidism
  • Eye conditions
  • Injuries
  • Eye surgery
  • Myopia

Why does CBD Work for Treating Glaucoma?

Studies 1 have shown that CBD products contain different useful medicinal components such as vaso-relaxant, which can help to increase the level of ocular blood flows. In addition, the anti-inflammatory properties are shown to provide therapeutic alleviation for common symptoms of glaucoma. This is the reason why more and more people are looking to treat themselves with CBD products.

In addition, many patients often suffer from unexpected uncomfortable symptoms such as vomiting, nausea, and severe pain. Therefore, they turn to CBD treatment mainly because these products contain analgesic and anti-nausea properties. Of course, the consumption will depend on their particular stage.

What Are The Benefits of Using CBD to Treat Glaucoma?

Many studies have shown that CBD can help to relieve the intraocular pressure in the eye, thus alleviating symptoms and reducing the damages.

In general, glaucoma does harm your eyes due to the excessive release of a damaging chemical known as glutamate. This compound leads to the death of neurons in the retinal after the formation of peroxynitrite. Some scientific research has presented that CBD products can prevent the formation of damaging peroxynitrite 2 . As a result, it will provide the ultimate protection for the neuron nerves from glutamate-induce cell death.

In addition to minimizing cell death, CBD has also proved to be helpful in dealing with some risk factors.

The Endocannabinoid System & Glaucoma

All of us have an endocannabinoid system, which plays an essential part in inflammation and neuroprotection. Specifically, the CB1 cannabinoid receptors in the ocular tissues of our eye that are responsible for controlling intraocular pressure. Therefore, many scientists believe that the use of cannabinoid-based products such as CBD would have a positive effect on the endocannabinoid system and these cannabinoid receptors. In fact, the medications could potentially reduce the IOP and protect your retinal cells.

How Can I Use CBD to Treat Glaucoma?

If used properly, CBD can be a great option for many people. However, it’s important to remember that every person is unique and everyone’s reaction to CBD is different. The recommended dosage from each product can differ greatly, creating some confusion. Dosage may be different depending on the percentage of CBD oil you are using. On average, 25mg of CBD a day is effective for most people. For strong symptoms, the dosage can be increased slowly over a week until the symptoms feel better. This, of course, is different for every patient and should be monitored. For more details about dosage, see our post on CBD dosage.

What Are Studies Saying About Using CBD to Treat Glaucoma?

A lot of clinical and experimental studies have been implemented all over the world to find the linkage between CBD and Glaucoma. Many of these have discovered that CBD and cannabis products can be used as a natural approach to treat Glaucoma.

For instance, a study by a group of professors from the University of Aberdeen, UK had demonstrated how cannabinoid compounds such as CBD can relieve the common symptoms of Glaucoma 3 . This occurred as the cannabinoids successfully reduced the IOP and offered neuroprotective properties.

In 1972, another study was implemented, which found that taking cannabis would reduce IOP by 30 to 35 percent 4 . Both of these studies point out that every patient can potentially treat their Glaucoma conditions through the consumption of CBD products.

Since the early 1980s, a couple of studies have been conducted in the US and Europe on the use of CBD on glaucoma treatments 5 . Many of them have proved that different cannabinoid compounds such as CBG, CBD, as well as endogenous cannabinoids can effectively lower IOP when topically administered. More importantly, many histological studies present the direct part of ocular CB1 receptors in the reduction of IOP produced by cannabinoids.

However, a new study 6 doubts the benefits of CBD to treat glaucoma. It seems that CBD could even aggravate the symptoms of the disease.

These days, many ophthalmologists recommend their patients using CBD products rather than cannabis itself, particularly for those who are experiencing the mid-late stage of Glaucoma. Both CBD and Cannabis are able to provide therapeutic effects, but they are only short-term.

Cannabis & CBD For Glaucoma (Is It Effective?)

However, other cannabinoids have been shown to reduce intra-ocular pressure in the eye.

Learn how people are using cannabis to alleviate glaucoma pain.

Article By

Glaucoma is the leading cause of irreversible blindness worldwide, with estimates that nearly 80 million people were diagnosed with the disease by the end of 2020 [1].

Often labeled the “sneak thief of sight,” many people are left undiagnosed — leading to permanent and irreversible vision loss [2]. It’s characterized by increased pressure in the eyeball. Reducing this pressure within the eye is the only known treatment in the disorder.

Although a lot of sources suggest CBD as a way to treat the disorder, evidence suggests otherwise.

Instead, research has indicated that inhaled cannabis, specifically THC, not CBD, may help with glaucoma by reducing pressure in the eye — however, the link is not strong and current standard treatments are still more effective than using cannabis. [3].

In this article, we discuss glaucoma and its current treatments and discuss the current research on using cannabis for glaucoma symptoms.


Carlos G. Aguirre, M.D., Pediatric Neurologist

Updated on November 14, 2021

Table of Contents
    • 1. THC Reduces Intraocular Pressure
    • 2. THC Supports Optic Nerve Health
    Recommended products
    $49 – $229
    Royal CBD
    Royal CBD Oil 30 mL

    5 / 5

    Total CBD: 250 – 2500 mg
    Potency: 8.3 – 83.3 mg/mL
    Cost per mg CBD: $0.09 – $0.20
    Extract Type: Full-spectrum
    THC Content: <0.3%

    What Are The Benefits of Cannabinoids For Glaucoma?

    People with glaucoma have used medicinal marijuana for decades to help ease symptoms.

    Studies back in the 1970s found that smoking marijuana can indeed lower IOP, but it has a short duration, only lasting for three to four hours at a time.

    If you have glaucoma, it’s important to maintain lower eye pressure 24 hours a day, so smoking marijuana multiple times a day is not a practical solution.

    Studies have shown that THC is the molecule that lowers IOP. CBD, on the other hand, works against THC. Therefore, if you’re thinking of using cannabis oils to treat glaucoma, it’s best to use high-THC oil instead of high-CBD oil.

    There is a lot of debate about this, however.

    THC Has Two Key Advantages:

    1. It reduces intraocular pressure (IOP)
    2. It supports nerve health

    The two major cannabinoids found in cannabis, tetrahydrocannabinol (THC) and cannabidiol (CBD), are both compounds that influence the body’s endocannabinoid system (ECS) but have very different effects.

    Now, when people talk about marijuana they’re usually thinking of the effects of THC, which is the part of the cannabis plant that gives us the euphoric feelings or of being “high”.

    While it also has other side effects, such as dizziness, loss of coordination, anxiety, paranoia, and increased heart rate, THC is strongly linked to reducing IOP in many studies.

    1. THC Reduces Intraocular Pressure

    There are many receptors for cannabinoids in the ECS. THC interacts with them, though the mechanics are still unknown. What is known is that this interaction reduces IOP while CBD, the other type of cannabinoid found in cannabis, interferes with THC activity.

    It’s theorized that there is a high concentration of the CB1-type cannabinoid receptors in the eye. This is why smoking marijuana or consuming THC oils and edibles can help lower IOP.

    2. THC Supports Optic Nerve Health

    With glaucoma, reducing intraocular pressure isn’t always enough to prevent vision loss.

    Something known as glutamate-induced neurotoxicity also appears to play a significant role in glaucoma.

    Sufferers tend to have an elevated level of glutamate – the major neurotransmitter found in the eye – the excess glutamate accumulates in the retinal ganglion cells and damages neurons.

    New research has found that CBD and THC can protect against this glutamate-induced cell death since they are both antioxidants.

    What CBD Can Help With: Glaucoma Risk Factors

    While CBD may not help with glaucoma directly, it can help with other issues that may aggravate existing IOP issues. Let’s take a look at them:

    1. CBD & High Blood Pressure

    CBD oil has been shown to reduce blood pressure and manage stress due to its ability to increase blood flow during times of stress [10].

    CBD acts as a vasodilator — it allows the blood to flow more freely by relaxing the smooth muscle cells within blood vessels and taking away pressure placed on the arteries.

    2. CBD & Diabetes

    Diabetes is a major cause of two specific types of glaucoma known as open-angle glaucoma (the most common form of the disease), and neovascular glaucoma.

    There are several theories as to why this happens — including such processes as inflammation in the eye, retinal cell death from high blood sugar levels, and the development of dysfunctional blood vessels in the eye.

    Chronic inflammation due to insulin resistance is a key factor in developing type 2 diabetes. Researchers have found that the anti-inflammatory properties of CBD treat this inflammation, thus improving the body’s metabolism and glycemic control [11].

    What does this mean?

    CBD can reduce inflammation that leads to developing type 2 diabetes, which may reduce the chances of diabetic-induced glaucomas.

    3. CBD & Inflammation

    Cannabinoids have been shown to be anti-inflammatory and immunosuppressive agents — largely due to their interactions with the ECS.

    They do this by inhibiting cell proliferation, and suppressing inflammatory cytokines [12].

    What does this mean?

    Simply put, CBD can reduce inflammation and influence certain immune cells.

    Can CBD Oil Help With Glaucoma?

    When using cannabis for glaucoma, there are three main things to remember:

    1. Oils high in CBD are not recommended if you have glaucoma — THC is the only cannabinoid backed by research to be a potential treatment for glaucoma
    2. Always follow the advice of a medical practitioner — be open about your interest in trying cannabis products to support your symptoms
    3. When it comes to dosing, the key is to start low and go slow

    There are different methods for treating glaucoma with cannabis. You can try topical eye drops or take in the form of oral drops, pastes, capsules, or in tea or lozenges. Concentrations vary greatly between products and how it is prepared.

    As we are all different, the dosage will vary with each individual. We recommend starting with a small dose, such as 10 mg of extract per day, and see how you react.

    As everyone responds to cannabis differently it may take some trial and error to get the right dose for you.

    Keep a daily journal of dosages, timings and any symptoms. This will help you to find your personal optimal dose.

    It’s important to note that higher doses (>40 mg) of CBD increase IOP. So it is extremely important to read the label of the product you are using.

    Use cannabis oils, do not smoke marijuana. Smoking marijuana long-term is not recommended as a treatment for glaucoma due to its short duration of action and risk of lung damage over time.

    Is Cannabis Oil Safe?

    You can’t overdose on CBD.

    However, quality counts.

    According to the World Health Organisation (WHO) CBD oil, in its pure state, does not cause harm or have the potential for abuse even at high doses [13].

    The research we have discussed here is based on using high-quality CBD. It’s important you make sure you use a high-quality CBD product that is free from contaminants and artificial additives.

    CBD oils may have some side effects — especially if you’re using a CBD oil that also has THC inside (recommended for glaucoma).

    The main side-effects of CBD and THC supplements include:

    • Paranoia
    • Dizziness
    • Anxiety
    • Fatigue
    • Headaches
    • Low blood pressure

    What is Glaucoma?

    The name glaucoma belongs to a group of eye diseases that damage the optic nerve in the back of the eye. It tends to worsen gradually over time.

    Most commonly, this is due to increased pressure inside the eye — known as intraocular pressure (IOP).

    The front of the eye produces what is known as the ‘aqueous humor’, a fluid that is continuously drained from the eye. If this fluid doesn’t circulate out of the eye properly, it builds up — causing increased pressure within the eyeball.

    Glaucoma may also be caused by poor blood supply to the optic nerve fibers or a weakness in the nerve structure of the eye [4].

    There Are Two Types of Glaucoma

    1. Open-Angle Glaucoma

    Open-angle glaucoma (OAG) is the most common type of glaucoma, accounting for at least 90% of all glaucoma cases [5].

    OAG happens when the aqueous humor (the clear liquid that lubricates and nourishes the inside of the front of the eye) becomes blocked and doesn’t drain properly. This causes pressure to rise in the eye, eventually damaging the optic nerve.

    Often there are no warning signs, with loss of vision occurring gradually over several years without pain or discomfort.

    With early detection, you can treat and slow down the condition.

    2. Angle-Closure Glaucoma

    Angle-closure glaucoma (ACG) is different from OAG in that the eye pressure can rise rapidly. It’s a rare form of the disorder.

    ACG happens when the peripheral part of the iris — the colored part of the eye — becomes blocked over the drainage canals. The pupil will enlarge too much or too quickly.

    Symptoms of Glaucoma

    • Blurry vision
    • Seeing “halos” in the eyes under bright lights
    • Headaches
    • Nausea
    • Vomiting

    Not all patients with glaucoma will have elevated intraocular pressure, but what’s been found is that for every mmHg(a measurement of pressure) that intraocular pressure is lowered, it reduces the risk of the disorder by 10% [6].

    Anyone can get glaucoma, however, some people are more at risk than others.

    Risk Factors for Glaucoma

    • Family history of glaucoma
    • Diabetes
    • Aged 40 years and over
    • Previous injuries to the eye
    • Hypertension
    • High eye pressure
    • Myopic or “near-sighted”

    If you experience any of the following symptoms you should see your eye specialist as soon as possible.

    • Vision loss
    • Halos in bright lights
    • Redness in the eye
    • Eye pain
    • Blurred vision
    • Nausea and vomiting

    It’s important to note that symptoms can vary greatly between individuals, you may have some or none of the symptoms mentioned.

    This is why it is important to have regular visits with your eye specialist to ensure the condition is detected in its early stages.

    How is Glaucoma Diagnosed?

    As glaucoma initially causes peripheral vision loss (side vision) undetectable to the patient, regular eye check-ups — especially after the age of 40 — are essential to screen for glaucoma, assessing if further examination is needed.

    A Glaucoma Test Usually Includes the Following:

    • Optic nerve check with an ophthalmoscope
    • Eye pressure check (tonometry)
    • Visual field assessment if needed — this tests the sensitivity of the peripheral vision, where glaucoma initially starts.

    Conventional Treatments for Glaucoma

    Most treatments for open-angle glaucoma are aimed at lowering and controlling eye pressure or decreasing the production of fluid in the eye. The most common treatment is specialized eye drops — an ophthalmologist decides on which treatment to use or a combination of therapies.

    1. Eye Drops

    These are the most common initial forms of treatment and are classified by their active chemical ingredient. These include prostaglandins, beta-blockers, alpha agonists, and rho kinase inhibitors. Certain drugs should not be used with CBD, so always speak to your doctor first if you’re using any medications (prescription and over-the-counter.)

    Common Side Effects of Eye Drops:

    • Eye drops that contain prostaglandins can cause stinging, burning, and eye color change.
    • Beta-blocker medications used in a variety of glaucoma eye drops can cause reduced heart rate and adverse side effects in individuals with heart and lung problems such as emphysema, diabetes, and depression.
    • Alpha agonist-based eye drops can cause burning, stinging, fatigue, headache, and drowsiness.

    2. Oral Medications

    Medications such as Carbonic Anhydrase Inhibitors (CAIs) can be used in conjunction with eye drops.

    CAIs can cause systemic side effects such as transient myopia (short-sightedness), frequent urination, tingling of the extremities, and lightheadedness.

    3. Selective Laser Trabeculoplasty (SLT)

    Laser treatments are performed if eye drops have failed to control deterioration in vision. The effects of laser treatment are often not permanent, and many patients will need to return to medications.

    Side Effects of Selective Laser Trabeculoplasty (SLT) May Include:

    • Mild side effects include soreness, redness, and blurring of vision.
    • Elevated Eye Pressure — In some cases the eye pressure can increase after the procedure. This increase in eye pressure is usually temporary and may be treated with additional eye drops or oral medications. Very rarely this increase in eye pressure can persist and require more invasive surgical procedures to be performed.
    • Peripheral Anterior Synechiae — adhesion of the iris to the cornea.
    • Inflammation & Swelling — In rare cases, selective laser trabeculoplasty (SLT) can lead to persistent inflammation within the eye. This is a potentially serious complication that can lead to other problems in the eye.

    4. Surgery (Trabeculectomy)

    Surgery is performed if eye drops, medications or laser has failed to control the pressure in the eye. Surgery can be effective, however, there are risks involved.

    Side Effects of Surgery Include:

    • Postoperative infection
    • Drooping eyelid
    • Double vision
    • Swelling
    • Bleeding
    • Developing a hole near the operation site
    • Scarring
    • Low IOP (hypotony)

    In severe cases, some people experience:

    • Hemorrhaging inside the affected eye
    • Choroidal detachment
    • Vision loss
    • Loss of the eye itself

    If treated and monitored, glaucoma will usually not lead to blindness. Only about 5% of patients with glaucoma experience vision loss. While it isn’t a condition that can be cured, there are many options available to maintain IOP at normal levels. These options include medication, laser, and surgery.

    Final Verdict: Using Cannabis for Glaucoma

    Most of the research up until this point shows that THC is effective in reducing IOP, while CBD interferes with THC activity.

    For the small percentage of people who suffer continued vision loss even after controlling their IOP, THC is an antioxidant that can help prevent retinal ganglion cell apoptosis.

    Unfortunately, since CBD does not relieve IOP, one would need to find an oil that is high in THC and avoid CBD specific oils.

    Of course, you should also continue with the medication schedule ordered by your ophthalmologist. To prevent any drug interactions, always check with your doctor before beginning any supplemental treatment.

    Using Marijuana to Treat Glaucoma

    Now with recreational marijuana legalized in Michigan, it’s easier for glaucoma patients to substitute traditional treatment methods for a joint. But does it hurt more than it helps? A University of Michigan expert weighs in.

    Marijuana increased in popularity in the mid-1970s when there was interest in cannabinoids for reduction in intraocular pressure (IOP), which is the fluid pressure inside the eye. Now, its usage has increased due to its pleasure-inducing side effects, and behind tobacco, alcohol and caffeine, it is the most widely used drug in society, according to Michigan Medicine ophthalmologist, Theresa M. Cooney, M.D.

    Michigan voters took to the polls in November 2008 and voted in favor of the Michigan Medical Marijuana Act (MMA), which protects people with specific medical conditions from penalties under state law who use marijuana for medical purposes. More recently, recreational marijuana has also been legalized in Michigan.

    As of 2019, 23 states, including Michigan, have legalized medical marijuana and some people are substituting their glaucoma medication with the drug. But does marijuana help? Cooney says the answer is complicated.

    Glaucoma, the second leading cause of blindness in the United States (first for African Americans in the United States), causes optic neuropathy, a progressive loss of visual field and can lead to permanent, irreversible vision loss if not diagnosed and treated appropriately.

    A debilitating condition

    The MMA allows the usage of prescribed marijuana for “treating or alleviating pain, nausea, and other symptoms associated with a variety of debilitating medical conditions”, which is defined as producing one or more of the following:

    Not all cases of glaucoma produce symptoms that classify it as a “debilitating medical condition” like closed-angle glaucoma, according to Cooney. The three types of glaucoma are:

    Open-angle (chronic) glaucoma

    Closed-angle (acute) glaucoma

    Open-angle glaucoma is a chronic medical condition that is generally painless and although vision threatening, it is a slow or non-progressive disease for which medical and surgical treatments are available. Glaucoma eye drops, registered by the Food and Drug Administration (FDA), have long-term, proven efficacy if taken as prescribed.

    Closed-angle glaucoma is an acute medical condition with sudden onset, that typically lasts only hours to a few days. It can cause pain and/or nausea because of elevated intraocular pressures. However, once effective pharmaceutical treatment is in place, there are no longer symptoms that would be consistent with a debilitating medical condition, as defined by the MMA.

    Secondary glaucoma occurs when an identifiable source causes increased eye pressure that results in optic nerve damage and vision loss. This can be closed-angle or open-angle glaucoma.

    Marijuana vs. traditional treatment

    There are several classes of drugs proven to be effective as medical treatments for glaucoma. Recent glaucoma drops have also shown effectiveness for up to eight hours.

    Aside from medications, there exist various surgery options for patients, such as the Xen gel stent , when a tiny tube is implanted in the eye to preserve vision, and the trabeculectomy, when a piece of tissue is removed from eye to create an opening to drain fluid.

    Combining medication and marijuana is not recommended, says Cooney, because “we don’t know how marijuana interacts with traditional treatment methods since there aren’t studies investigating that yet.”

    She adds that side effects of these traditional medical therapies are generally known to be considerably more mild than those associated with high-dose marijuana usage.

    The effects of marijuana are also variable, since not all marijuana is created equal and it is not FDA approved, which is a serious health concern.

    “Marijuana can be laced with anything,” says Cooney. “There are variable potencies of preparation and more than 400 different chemicals involved.”

    Marijuana is a Schedule I controlled substance under federal law, meaning that there is a high potential for abuse and there is a lack of accepted safety for its use under medical supervision. It is discouraged from being used in place of any traditional, and studied, treatment options.

    The good and the bad

    According to Cooney, marijuana can create a 25 percent IOP reduction in 60 to 65 percent of people with or without glaucoma. What exactly causes this within the drug is unknown.

    The problem is that IOP reduction lasts from 3 to 3.5 hours. To treat glaucoma effectively, IOP must be controlled around the clock, which likely leads to compliance issues.

    “You’d need to smoke eight to 10 marijuana cigarettes a day for them to have the same effectiveness as regular, glaucoma drops,” says Cooney. “That’s 2,920 to 3,650 a year.”

    Aside from the high, marijuana can substantially reduce blood pressure, which is a systemic problem. Reducing blood flow to the optic nerve means increasing susceptibility to optic nerve damage, which worsens glaucoma.

    Decreased blood pressure is present within an hour, but in some who experience postural hypotension with hypertension, it can be as quick as 10 to 15 minutes.

    Another systemic problem: smoking marijuana cigarettes can cause cardiac palpitations within two to three minutes, which will only return to normal after 90 to 120 minutes.

    More apparent than physical alterations are the psychotropic effects that can cause euphoria, dysphoria and disruption of short term memory. These effects prevent individuals from safely driving, operating heavy machinery or functioning at maximum mental capacity.

    Because marijuana is not filtered, neither are the cigarettes. Long-term usage can cause emphysema-like respiratory changes because of their release of tar, carcinogens and other volatile materials.

    “There’s a higher concentration of these carcinogens in marijuana than tobacco, which increases your cancer risk” says Cooney.