by Seshata on 26/01/2015 | Cannabis News Medicinal

Top 4 benefits of cannabis for glaucoma

The ability of cannabis to improve the symptoms of glaucoma has been demonstrated in various studies, but doubts still remain over its efficacy and consistency within patient populations. Despite this, many medical cannabis patients utilize cannabis for glaucoma, and report subjective improvements in various symptoms.


The ability of cannabis to improve the symptoms of glaucoma has been demonstrated in various studies, but doubts still remain over its efficacy and consistency within patient populations. Despite this, many medical cannabis patients utilize cannabis for glaucoma, and report subjective improvements in various symptoms.

Reduces intraocular pressure

Increased intraocular pressure (ocular hypertension) is the risk factor in the majority of glaucoma cases, although it is absent in certain populations in almost 50% of individuals suffering from open-angle glaucoma (OAG)—the most common type, comprising around 90% of all cases. Intraocular pressure is determined by the production of aqueous humour in the eye coupled with the rate of drainage of the aqueous humour via the trabecular meshwork, a spongy tissue located at the base of the cornea. Consistently high intraocular pressure can cause progressive damage to the optic nerve and the retinal ganglion cells that contain light-sensitive photoreceptors. If damage is severe enough, total blindness can result.

Glaucoma is a common disease affecting the eyes, that increases in frequency with age (© 0olong)
Glaucoma is a common disease affecting the eyes, that increases in frequency with age (© 0olong)

During his decades-long tenure at the University of the West Indies, the respected pharmacologist Professor Manley West conducted landmark research into cannabis as a potential treatment for glaucoma alongside the noted ophthalmologist Dr. Albert Lockhart. As a result of their work, which began in 1964 and investigated traditional cannabis use in Jamaican communities, they developed cannabis-based eye-drops and gained approval to market their product in Jamaica under the name “Canasol”, in 1987. Professor West sadly died in 2012, and will be much missed by the medical cannabis community in Jamaica and beyond.

Canasol has been demonstrated to be effective in lowering intraocular pressure, and has also been shown to potentiate the effectiveness of other widely-used glaucoma drugs such as Timolol. Recently, a new and improved drug was developed by the same research team; this drug is known as Cantimol, and contains Canasol and Timolol, but has not yet been approval for market. Canasol contains no psychoactive cannabinoids and has also been widely prescribed by physicians in the USA and Canada—and has apparently been used by patients in the UK and Australia too, despite not having market approval or a legal precedent for use.

Miotic

A common phenomenon found in glaucoma patients is mydriasis, in which the pupil becomes dilated. In fact, it is thought that extreme mydriasis may actually cause the characteristic bulging-out of the iris in attacks of closed-angle glaucoma—in order for the pupil to dilate, muscle tissue in the iris (known as the dilator pupillae) must contract. When muscle tissue contracts, it bulges, and in extreme cases this bulging tissue can expand into the anterior chamber (the fluid-filled space between the iris and cornea) and press up against the cornea, totally preventing escape of aqueous humour via the anterior chamber and into the trabecular meshwork.

The opposite of mydriasis is miosis (not to be confused with the form of cell division known as meiosis). Miotic drugs are highly useful in glaucoma treatment, not only CAG, as constriction of the pupil allows increased drainage of aqueous humour into the trabecular meshwork. Cannabis has been shown to possess miotic properties on various occasions, including one notable case of apparent acute cannabis poisoning in a 20-month-old infant.

Analgesic

Acute glaucoma can cause rapid loss of vision due to total blockage of the fluid drainage channels (© Community Eye Health)
Acute glaucoma can cause rapid loss of vision due to total blockage of the fluid drainage channels (© Community Eye Health)

While the majority of glaucoma cases are painless, the rarer form of the disease (known as closed-angle glaucoma or CAG) is characterized by sharp, stabbing pains in the eyeball and rapid loss of vision, which may be permanent if not given medical attention. Closed angle glaucoma differs from the more common form in that it produces acute symptoms instead of chronic (and generally painless) symptoms. An attack of CAG is considered a medical emergency, and occurs due to a total blockage of the trabecular network (rather than a progressively reduced ability to drain aqueous humour, as with OAG) caused by a sudden bulging forward of the iris.

Although not specifically tested as an analgesic in glaucoma cases, cannabis’ wide-spectrum efficacy as an analgesic, mood-enhancer and muscle relaxant may provide subjective relief to individuals suffering from acute attacks of closed-angle glaucoma.

Anti-inflammatory

On the basis of recent research, some medical professionals are beginning to suspect that persistent, low-level inflammation in the trabecular meshwork may have an important role to play in the progressive, chronic form of glaucoma, OAG. As well as this, a further type of glaucoma that is often found in patients suffering from uveitis (inflammation of the uvea, the area of the eye that contains the iris and the ciliary body) is known as inflammatory glaucoma as it has been proven that inflammation of the trabecular meshwork is to blame. In most respects, inflammatory glaucoma resembles OAG, but is characterized as occurring as a secondary symptom of uveitis.

Cannabis has been proven time and time again to be a useful and effective anti-inflammatory for a range of different conditions, although no formal studies have been conducted on the potential of cannabis to reduced glaucoma-related inflammation. As understanding of the role inflammation has to play in the progression of the disease increases, it may well prove to be the case that cannabis also provides relief to glaucoma patients due to its anti-inflammatory properties.

Antinauseant/antiemetic

Attacks of closed-angle glaucoma are often accompanied by secondary symptoms of nausea and vomiting, which is believed to arise as a result of a phenomenon known as the oculoemetic reflex. Various past studies have shown an association with ophthalmic surgery and post-operative vomiting (particularly squint surgery, which causes vomiting in 41% of patients), which gave rise to the possibility of the oculoemetic reflex existing.

This diagram illustrates the normal movement of aqueous humour out of the eye (© National Eye Institute)
This diagram illustrates the normal movement of aqueous humour out of the eye (© National Eye Institute)

It is believed that noxious (painful or unpleasant) stimulation of the orbital nerves that surround the eye sends signals to the area postrema of the medulla oblongata, the section of the brain that is often simply known as the vomiting centre. The brain then sends signals to the gastrointestinal tract via the vagus nerve (a fundamental part of the parasympathetic nervous system, which controls cardiac and gastrointestinal function), which in turn causes the vomiting reflex by stimulating retroperistalsis (backward/upward movement of GI tract contents).

It is not known what precise role the endocannabinoid system has to play in regulation of vomiting, but it has been shown that cannabinoid receptor agonists such as THC appear to directly suppress vomiting and nausea by agonizing the CB1-receptor –while antagonists of the CB receptors such as CBD are neutral, and inverse agonists actually cause nausea.

Comment Section

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Daniela vergara

Can you recommend any particular strains? Thank you!

27/01/2015

Rozar@Abud-e.com

Medicinal Marijuana and also Marijuana products have been proven to lower the IOP level within individuals that is a major cause of Glaucoma. Medicinal Marijuana has THC that is the useful component that keeps IOP level very low.

03/06/2015

Kage

Please recommend a clone strain of cannabis that I can grow at home. My mom has severe glaucoma, is on 2 drops, and has had laser surgery to open the ducts in her eyes. She will kill herself if she goes blind, so I really want to prevent that!!!! We are both willing to do anything that helps.

26/06/2015

Donna King

Your website was in the listing I pulled up when I googled cannabis and glaucoma. I selected your listing because it said " the ability of cannabis to improve the symptoms of glaucoma has been demonstrated in various studies. You have a very well written article that has NO REFERENCES TO STUDIES. Disappointing.

26/07/2015

Margot

How can I get a prescription for Canasol if it isn't approved in the US?

31/03/2016

Marc Lieberman, M.D.

This account is not well rooted in the medical literature, and exaggerates the effectiveness of cannabis. The brief lowering of the internal eye pressure ( IOP= intraocular pressure) is NEITHER as persistent NOR as effective as obtained by readily available, generic topical eye drops for glaucoma. Moreover, the cannabis effect on the complex blood pressure gradients within and behind the eye itself— felt to play a role in glaucomatous damage— have not been teased out, and hence its many active agents may be working counter to its effects of transient pressure-lowering....

A definitive & up-to-date summary article was recently published by Gary Novack, PhD., a renowned ocular pharmacologist: Curr Opin Ophthalmol 2016, 27:146 – 150. As with many other promising medical effects of cannabis on human biologic systems— such as relieving pain, spasticity, etc.— more effective 'mainstream' treatments are better documented and effective. Perhaps the modest-at-best role of cannabis products might be as an adjunct— but NOT a substitute— for pharmacologically & effective professional management of this potentially blinding eye disease.

28/12/2016

Scarlet Palmer

Dear Marc,

Thank you for your comment and feedback on this article. I will bring it to the author's attention so that necessary amendments can be made.

With best wishes,

Scarlet

30/12/2016

Maria

Mr Lieberman,

I have been suffering from uveitis these past 3 years and doctors say they can' do nothing but prescribe me cortisone, i still have inflammation in my optic nerve.
I would like to ask you if you think that cannabis could help me get rid of this disease? or at least make the inflammation disappear, my ophtalmologist says that if it continues this way I might loose my sight.

Thank you a lot,

Maria L

27/03/2017

Tdog

Need info for canbabis oil for acute open angle glaucoma with macular degeneration please !!!

26/01/2017

Scarlet Palmer

Dear Tdog,

Thank you for your comment. We are sorry to hear about your situation. Unfortunately, as Sensi Seeds is not a medical practice, we are not able to provide any advice relating to medical situations other than to consult your doctor or other licensed medical professional. This article, written specifically for healthcare providers who may not be aware of the many properties of cannabis, may be useful to you in talking with your doctor. You could also try to contact local medicinal cannabis support groups, if you have not already done so. In the UK, there is the United Patients Alliance (you can find them on Facebook) and in the US and EU there are many branches of NORML (google NORML followed by your area name). We hope this is helpful.

With best wishes,

Scarlet

27/01/2017

Al Morentin

I have the painful kind of Glaucoma. It's aggressive and it hurts really bad... as well as vision loss in my right eye... It took a long while to find a solution for myself... I have been managing my Glaucoma with cannabis oil, a healthy diet, and proper supplementation for the past 3 years. It took me a long while to figure it out, but I've stopped mine in its tracks and actually improved my vision... It's a little bit of work, but my eyesight is worth it... And, the other really awesome thing is the fact that I have the pain under control for the most part... I still get flare-ups from time to time, but 3 years ago I was in pain every waking moment of the day... every day... I basically have my life back.

Just wanted to share a glaucoma success story because I know there aren't a lot of them out there.

12/03/2017

Scarlet Palmer

Hello Al,

Thank you for sharing your story, it is indeed really good to hear success stories and I'm really glad you have been able to improve your quality of life.

With best wishes,

Scarlet

13/03/2017

Lesley Corriveau

I have just started cannabis oil for my glaucoma. Do you put the oil under your tongue or is it like an eye drop. I am new to this and I am taking the oil about half the size of a grain of rice and rubbing it on my gums. What is the name of the oil you are using. I would appreciate you getting back to me.

21/03/2017

Jessie

What type cannabis oil did you use
. My grandfather has it and he been look all over for a good cannabis oil to help Him out

08/04/2017

George Cohen

I, too, have glaucoma & I'm looking for CBD oil, or cannabis oil that might help--
1--where can I buy some?
2--how much do I use?
3--Is it under the tongue--sublingual, or applied onto the eyes?
4 my brother has uveitis--same questions for his condition.
THANK YOU.

11/04/2017

Scarlet Palmer

Hi George,

Here you can read more information about Sensi Seeds CBD Oil, including how to take it. Unfortunately, as Sensi Seeds is not a medical practice, we are not able to provide any advice relating to medical situations other than to consult your doctor or other licensed medical professional. This article, written specifically for healthcare providers who may not be aware of the many properties of cannabis, may be useful to you in talking with your doctor. You could also try to contact local medicinal cannabis support groups, if you have not already done so. In the UK, there is the United Patients Alliance (you can find them on Facebook) and in the US and EU there are many branches of NORML (google NORML followed by your area name). We hope this is helpful.

With best wishes,

Scarlet

21/04/2017

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