CBD and Glaucoma: Does It Help Reduce Eye Pressure?

Illustration of an Eyeball and Eyeglasses beside CBD Oil with Doctor
Written by Livvy Ashton | Last updated: July 13, 2021

CBD (cannabidiol) alone isn’t going to help your glaucoma. In fact, it can be detrimental to the disease.

However, when used in conjunction with other cannabinoids, CBD for glaucoma can work as an effective treatment.

There’s a lot of false information out there that suggests CBD alone is an effective way to treat the condition. This information can be dangerous to someone that actually suffers from the disorder.

In this article, we’ll be looking at the facts and helping you understand how certain cannabinoids can treat glaucoma.

What are the Effects of CBD on the Eyes?

On a normal healthy person, CBD has no known negative effects on the eyes however that isn’t the same for people with glaucoma as some studies suggest.

Using CBD alone in the form of an isolate can be detrimental if you have glaucoma. One study from Indiana University found evidence to suggest that CBD raises the pressure inside the eye [1]. If this is true, CBD could worsen the primary underpinning of the disease.

The study was conducted on mice and found that CBD raised eye pressure by 18 percent. This lasted for up to four hours after the CBD was administered.

As you will know if you or someone close to you suffers from glaucoma, high eye pressure is a primary risk factor for people with the disease. High eye pressure can quicken the damage to the optic nerve at the back of the eye which could ultimately lead to blindness.

The best way to fight glaucoma is to lower eye pressure as much as possible. This will slow down any permanent damage that may be taking place. With this in mind, CBD alone isn’t recommended as a treatment for the disease.

If you were hoping to use CBD for glaucoma, do not fear, all hope is not lost. Other cannabinoids such as THC (tetrahydrocannabinol) have been found to lower eye pressure and have a positive effect on glaucoma.

When a true full-spectrum product is used to treat glaucoma CBD can actually benefit you. As we mentioned, CBD alone can be detrimental to the disease however when used in conjunction with THC it can have some positive effects.

Is THC Better for Glaucoma Than CBD?

CBD Oil and THC Oil with Hemp Leaf in a Wooden Slab

THC as a singular cannabinoid certainly helps people with glaucoma more than CBD alone.

Numerous studies show that both delta 9-THC and delta 8-THC have a significant effect on optic nerve health. Evidence shows that THC not only reduces intraocular pressure but also helps to protect against neuron damage.

Research shows that both THC and CBD can protect against cell damage due to elevated levels of glutamate. CBD can indirectly help glaucoma as long as it is combined with other cannabinoids in a balanced true full-spectrum product.

Let’s take a look at how THC and CBD can positively impact eye health and be used to treat glaucoma.

THC Reduces Intraocular Pressure

Lowering eye pressure is an important factor in treating glaucoma. From as early as the 1970s, it has been common knowledge that THC lowers intraocular eye pressure. So, how does it work?

THC interacts with the receptors in the body’s endocannabinoid system. Studies show that THC reacts with receptors in the eye [2].

CB1 receptors have been found in the ciliary epithelium, the corneal epithelium, and the endothelium of the eye. It is believed that THC interacts with these receptors and as a result, intraocular pressure is lowered.

THC Decelerates Vision Loss

THC has been found to decelerate vision loss according to a study published in Experimental Eye Research [3].

The study tested the effects of THC on rats with retinitis pigmentosa — a genetic eye disease that leads to blindness. After a 90 day treatment, the rats that consumed the cannabinoid gained better scores on vision tests.

The THC rat group also acquired 40 percent more photoreceptors than the untreated control group. Those are some impressive results.

The potential that THC alone has to slow down blindness is staggering.

THC & CBD Support Optic Nerve Health

THC and CBD together have been found to support optic nerve health [4]. People with glaucoma have an excess of glutamate — a major neurotransmitter in the eye.

In glaucoma sufferers, this neurotransmitter accumulates in the retinal region and damages cells, eventually leading to vision loss. This is called glutamate-induced neurotoxicity.

THC and CBD help protect against the condition, potentially preventing blindness and prolonging vision loss.

CBD Oil and Glaucoma

Illustration of healthy eye vs glaucoma eye on white background

Most commercially available CBD oils will not help glaucoma, in fact, they could have an adverse effect. Even CBD oils labeled as full-spectrum aren’t going to cut it when it comes to this disease, as they simply contain too much CBD and not enough THC.

The best oil for glaucoma is a true full-spectrum THC-containing cannabis oil. Both delta 9-THC and delta 8-THC can be used to treat glaucoma with excellent results. Finding an oil that contains both cannabinoids is the best way to treat the disease.

Delta 9 and delta-8 THC are psychoactive so they will get you “high.” This is something to keep in mind if you are looking for cannabis to treat glaucoma because unfortunately, this side effect is unavoidable.

Research shows that delta 8-THC is slightly less psychoactive than delta 9 but you will still experience a “high.”

If you’re looking for a glaucoma treatment that helps but you are put off by the thought of being overly intoxicated, a delta 8-THC oil or tincture is worth trying.

If you can deal with the psychoactive effects of full-spectrum THC-containing cannabis oil, it will benefit the disease massively. Just remember not to operate any machinery or vehicles while medicated.

Is THC-Containing Cannabis Oil Legal?

Any cannabis oil that contains over 0.3% delta 9 THC is illegal under federal law, however, state law allows it depending on the state that you reside in.

Cannabis products, for the most part, are also banned across Europe and the UK, so make sure you know the law in your area.

Delta 8 THC is still technically legal under federal law, which means it is unbanned across the US. Regardless, make sure to check your state law if you are unsure of your local restrictions.

In most of Europe and the UK, any form of THC is banned by law, making delta 8 THC illegal as well.

Check the law in your country and region if you are planning on using THC for glaucoma. Cannabis is becoming more accepted as a medicine. Even in banned countries such as the UK, THC-containing products may be available on prescription from your doctor.

CBD vs. THC For Glaucoma

There are many benefits to using THC and CBD for glaucoma. Both cannabinoids have their place in treating the disease, but like any medication, there are some downsides.

If you have glaucoma and are considering using cannabis oil to treat it, you will have to weigh up the pros and cons. Doing this will help you understand whether this route is going to work for you.

THC CBD 
Pros
  • THC decelerates vision loss
  • It reduces intraocular pressure
  • Supports optic nerve health
  • Analgesic qualities — can reduce pain
  • Aids in the support of optic nerve health when used alongside other cannabinoids
  • Vaso-relaxant — increases the level of ocular blood flow
  • Anti-inflammatory — can reduce some side effects of glaucoma
  • Analgesic qualities — can reduce pain
  • Anti-nausea qualities — can help reduce the side effects of other glaucoma meds
Cons
  • Is psychoactive — will get you “high” (can become an inconvenience)
  • Only effective for three to four hours before another dose is needed
  • High-quality oils and extracts are expensive
  • Illegal in some states and across Europe
  • When used alone it can raise intraocular pressure
  • Must only be used alongside the psychoactive cannabinoid THC

How to Use CBD Oil for Glaucoma?

CBD Oil on a Paper with Stethoscope and Hemp Flower Beside It

The best way to use CBD for glaucoma is in a true full-spectrum product that has a cannabinoid profile as close to the raw plant as possible. A delta 8 THC oil or tincture is another good option to consider.

You can use cannabis oil in a variety of ways to treat glaucoma. Full-spectrum oils are available in many forms. You will find pure oils, vape products, tinctures, capsules, gummies, and sprays.

You need to treat glaucoma 24 hours a day and unfortunately, the intraocular pressure-reducing qualities of THC don’t last long. You’ll need to medicate periodically throughout the day.

Studies from the National Eye Institute show that THC does lower IOP (intraocular eye pressure) by up to 30 percent. The downside is, IOP levels only stay this low for three to four hours.

If you’re going to use cannabis oil or another THC-containing product to treat glaucoma, you will need to medicate every three to four hours. This is great during the day but unless you plan on waking up every few hours at night, it is not so good.

Intraocular eye pressure levels increase during the night. This is mostly down to fluid distribution leading to choroidal vascular congestion when lying flat during sleep. This is a problem if you plan on using cannabis alone to treat glaucoma.

The answer is to use cannabis oil alongside other forms of glaucoma medication such as bimatoprost eye drops and/or acetazolamide pills.

Although you should continue using your prescription glaucoma meds, you may be able to reduce your intake and side effects by using cannabis oil alongside them.

How Much CBD Oil Should I Take for Glaucoma?

How much cannabis oil you take for glaucoma depends on a lot of factors.

Usually, one to two drops of cannabis oil under the tongue is sufficient for lowering intraocular eye pressure. Keep in mind, the strength of the oil you are using will ultimately affect the dosage.

If you are new to cannabis, start small with a 10 mg dose and increase once you know how you react to it. People react differently to THC so don’t be put off if you feel the need to increase or decrease your dose.

Speak to your local dispensary or get some advice on dosages for the specific oil you will be using.

No matter the strength or dosage you are taking it is important to remember to medicate every three to four hours to maintain low eye pressure.

Final Thoughts — Should You Use CBD for Glaucoma?

As you now know, CBD alone is not an effective treatment for glaucoma. The cannabinoid by itself can increase eye pressure which is a less than desirable effect if you have the disease.

If you have glaucoma, you should do your best to avoid CBD oils and stick to full-spectrum oils that are high in THC.

Glaucoma can’t be cured yet, but it can certainly be controlled. With the right treatment, the progression of vision loss can be slowed down dramatically and even stopped entirely.

People that suffer from glaucoma can lead perfectly normal lives with the right treatment. Cannabis can be a large part of that treatment and help you get back on the path to normality.

Cannabis oil or any other THC-containing products should not be used as a primary treatment for glaucoma. Any prescription medication should still be taken to reduce vision loss and prevent optic nerve damage.

Always check with your doctor before using cannabis alongside any existing medication.

References Used In This Article

  1. Miller, S., Daily, L., Leishman, E., Bradshaw, H., & Straiker, A. (2018). Δ9-Tetrahydrocannabinol and cannabidiol differentially regulate intraocular pressure. Investigative ophthalmology & visual science, 59(15), 5904-5911.
  2. Straiker, A. J., Maguire, G., Mackie, K., & Lindsey, J. (1999). Localization of cannabinoid CB1 receptors in the human anterior eye and retina. Investigative ophthalmology & visual science, 40(10), 2442-2448.
  3. Lax, P., Esquiva, G., Altavilla, C., & Cuenca, N. (2014). Neuroprotective effects of the cannabinoid agonist HU210 on retinal degeneration. Experimental Eye Research, 120, 175-185.
  4. Hampson, A. J., Grimaldi, M., Axelrod, J., & Wink, D. (1998). Cannabidiol and (−) Δ9-tetrahydrocannabinol are neuroprotective antioxidants. Proceedings of the National Academy of Sciences, 95(14), 8268-8273.

Livvy is a registered nurse (RN) and board-certified nurse midwife (CNM) in the state of New Jersey. After giving birth to her newborn daughter, Livvy stepped down from her full-time position at the Children’s Hospital of New Jersey. This gave her the opportunity to spend more time writing articles on all topics related to pregnancy and prenatal care.

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