Glaucoma is a type of disease that is characterized by damage to the eye’s optic nerves leading to a loss of vision. In the 1970s, research teams noticed that cannabis use was able to reduce intraocular pressure (IOP) linked to this neurological damage, although this reduction only lasted for a few hours.
Glaucoma, the leading cause of blindness, is often one of the medical conditions that is most widely cited as being effectively treated by medical cannabis, while the evidence for this assertion is lacking. Although cannabinoid-based medicines continue to show promise as the basis of future glaucoma treatments, the use of cannabinoids is not largely accepted as a suitable treatment for glaucoma. Cannabis is infrequently recommended by ophthalmologists for glaucoma treatment.
Does CBD help with glaucoma?
Research was conducted across several universities in Canada and the United States exploring the role of the body’s endocannabinoid system (ECS) in regulating intraocular pressure (IOP), but indicate that currently available cannabis medicines are unlikely to be effective for long-term treatment. [1] The American Glaucoma Society and the Canadian Ophthalmological Society produced position papers in 2010 that were highly critical of the efficacy of medical cannabis for glaucoma treatment. [2] [3] For more information, see The Endocannabinoid System Explained.
Historical Uses of Cannabis for IOP
In the 1970s, glaucoma was one of the first medical conditions to be used as justification for a compelling exemption to prevailing laws against cannabis use. Cannabis as a potential treatment for glaucoma was noted in a 1971 study, where smoked cannabis lowered intraocular pressure (IOP) among the participants by 25 to 30 percent. [4] The National Eye Institute (NEI) supported research into cannabis treatment of elevated IOP present in glaucoma beginning in 1978. [5] These studies were able to demonstrate that cannabinoids can temporarily lower IOP when given either by inhalation or orally, but not when they were topically administered. A 1984 study [6] in California gathered 20 ophthalmologists to study the effects of oral and inhaled cannabis on IOP levels of glaucoma patients, but only nine patients ultimately took part in the study. The results of the research were published in 2002 and were mixed. Many of the patients complained of unacceptable levels of psychoactivity from the oral THC administered during the study. Interestingly, the two patients with the best results took smaller doses than nearly all the other participants.
Cannabinoids for treatment of glaucoma
Glaucoma causes a buildup of pressure in the aqueous humor that is thought to damage retinal nerve cells. Endocannabinoid receptors are located throughout the eye, including the retina, the cornea, and surrounding tissues. These receptors are also located within the trabecular meshwork that drains the liquid intraocular aqueous humor from the eye. As the role of the endocannabinoid system within the eye has become better understood, additional therapeutic targets for cannabinoid medicines have emerged. In 2015–2016, evidence was found that cannabinoids can reduce IOP by engaging both the CB1 receptor in the eye and a lesser-known cannabinoid receptor, GPR18. [1] Both receptors play a role in controlling intraocular pressure. The two most prevalent active compounds produced by cannabis cultivars are the cannabinoids THC and CBD, both of which provide neuroprotective benefits, while THC also reduces IOP. Some preclinical data supports the application of these cannabinoids for neuroprotection, as this ability may slow the selective death of retinal ganglion cells, a mechanism that is directly linked to loss of vision in glaucoma patients. [7] [8] [9]
Medical disclaimer: the information contained in this article is for informational purposes only and does not constitute medical advice. Prior to making changes to your lifestyle or treatment plan, always consult with your doctor. When assessing suitability of CBD oil to treat glaucoma, or alleviate side effects of open angle glaucoma, assess the appropriate science based medical journals, and seek advice from people with experience in recommending medical marijuana products for pain and any other health related condition. Ocular vision loss is a very real threat. Prior to using any plant medicine, seek advice from a licenced medical professional.
CBD glaucoma dosage + THC
THC has been shown to reduce IOP at doses of 5 mg, four times daily; though the ability of THC to reduce IOP often declines over the course of the treatment, indicating that other IOP-lowering medications must be used simultaneously with cannabis.
Is CBD good for glaucoma?
For neuroprotection and anxiety, cannabidiol (CBD) products can be utilized without intoxication, and given sublingually or by spray, 5 mg CBD in the morning and again mid-afternoon. It can also be used throughout the day, as needed, but it is recommended that the last dose of the day happen prior to 5pm, as CBD can be wake-promoting.
For more immediate, short-term relief of IOP, start by inhaling 2.5 to 5 mg of THC. inhaled cannabis is effective for short-term reduction (three to four hours) in IOP due to glaucoma, but tolerance to THC builds quickly.
Does CBD lower eye pressure?
Topical cannabis products in the form of eye drops would be most effective and optimal, these formulations are typically hard to come by or just aren’t yet available. CBD eye drops and some cannabis eye drops are currently underway in clinical trials.
Best strains to relieve eye pressure
High-CBD strains are ideal for its potential neuroprotective effect on the optic nerve. Consistent and lasting reduction in IOP is unlikely to be achieved with high-THC cannabis alone, so use in combination with conventional glaucoma treatments is highly recommended, as uncontrolled IOP can cause permanent eye damage. Cannatonic or other high-CBD strains are recommended. High-THC varieties can provide short-term benefits as an adjunct therapy, but their use and efficacy should be discussed in depth with an ophthalmologist.
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1. https://dalspace.library.dal.ca/bitstream/handle/10222/64652/Caldwell-Meggie-MSc-VISC-July-2015.pdf?sequence=1&isAllowed=y
2. https://pubmed.ncbi.nlm.nih.gov/20160576/
3. https://pubmed.ncbi.nlm.nih.gov/20676153/
4. https://pubmed.ncbi.nlm.nih.gov/5109652/
5. https://nei.nih.gov/news/statements/marij
6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1358964/
7. https://pubmed.ncbi.nlm.nih.gov/16988594/
8. https://pubmed.ncbi.nlm.nih.gov/26881140/
9. https://pubmed.ncbi.nlm.nih.gov/28027538/
