Glaucoma Awareness Month

Did you know that glaucoma is the second-leading cause of blindness in the U.S.? It is six times more common among blacks or African Americans than among whites. According to the CDC, 50 percent of all glaucoma patients in the U.S. are expected to be Hispanic by 2050. People over 60 years of age, those with a family history of glaucoma, diabetes, or high blood pressure, are at higher risk. According to the American Academy of Ophthalmology, glaucoma affects an estimated three million people in our country. By 2050, this number will rise to 6.3 million as the U.S. population ages.

GLAUCOMA 

Glaucoma is a gradual loss of vision caused by damage to the optic nerve. There are two main types of glaucoma, open-angle, and angle-closure. Increased intraocular pressure leads to damage caused by fluid build-up in the eye. Essentially, this type of eye condition is without symptoms, and only 50 percent of people with glaucoma know they have it. Peripheral vision is usually lost first, and glaucoma can cause irreversible blindness if left untreated. 

Regular eye exams detect early signs of glaucoma. However, disproportionate numbers of Americans have no access to routine examinations. For this reason, the CDC supports glaucoma detection in all states through its Vision Health Initiative (VHI) Glaucoma Detection Program. Testing should occur every six to twelve months. 

TREATMENT 

There is no cure for Glaucoma once the damage is done. Lowering intraocular pressure with prescribed medications and catching it early through regular eye exams may help slow the progression. 

MMJ + GLAUCOMA

Perceptions and attitudes about the use of medical marijuana continue to evolve, with continued interest in their potential. Scientists hope to continue to investigate whether a component of medical marijuana could be a potential glaucoma treatment. 

Currently, no studies have shown that medical marijuana can lower intraocular pressure safely and effectively better than medications prescribed by an eye doctor. Neither the American Association of Ophthalmology, the American Glaucoma Society, nor the Glaucoma Research Foundation endorses medical marijuana for glaucoma treatment because of its controlled substance status, short-acting duration, the side effect of euphoric mood, and because it can temporarily lower blood pressure, potentially resulting in lower blood flow to the optic nerve. 

Previous studies are limited by examining only THC and not incorporating other cannabinoids, such as CBN, CBG, THCV, or the acidic (raw) cannabinoids. Animal studies funded by the National Eye Institute have shown that CBG and CBN can lower intraocular pressure and use of these cannabinoids may warrant further investigation. Most clinical studies are based on smoking as an administration method. Oral products taken with a fatty meal may have a longer duration of action but are not well studied in glaucoma. Available studies in glaucoma research often use a single-molecule compound of THC. The entourage effect of MMJ may prove to have additional benefits, and further research is needed.        

Studies over 50 years old show that THC reduces intraocular pressure for three to four hours when inhaled. THC has been shown to cause up to 25 to 30 percent reduction via CB1 and GRP-18 receptor activation. Eye pressure has to be maintained 24 hours a day to treat glaucoma. Since the effects of inhaled THC are short-acting and last 2-4 hours, dosing would suggest administration every four hours. 

On the other hand, in animal and human studies, CBD has been shown to increase intraocular pressure by decreasing the affinity of THC at the receptor site. Human studies showed that the addition of CBD to THC blocked the decrease in intraocular pressure caused by THC at a dose of 40mg CBD and should be avoided in glaucoma patients.

Both CBD and THC have neuroprotective properties. In glaucoma models, some studies have shown these effects to protect the retina. Talk to your recommending physicians about whether MMJ therapy is safe to treat symptoms of your qualifying condition if you have glaucoma. 

According to an article published in Glaucoma Today, patients of the PA MMJ program who use MMJ to reduce intraocular pressure would be best advised to seek a THC-dominant preparation. Those with stable intraocular pressure who wish to protect the retina may benefit from a combination of THC and CBD. https://glaucomatoday.com/articles/2020-july-aug/cannabis-and-glaucoma

 Of special note, Robert Randall (1946-2001) was the first federal IND medical marijuana patient to treat glaucoma. Robert received 10 MMJ cigarettes from the federal government from 1976 for most of his life and is reported to have passed away with his vision intact.

 If you are looking for more information about including medical marijuana in your treatment plan, we welcome you to contact us for a private consultation with a Maitri pharmacist

 TIPS 

• Early detection — schedule and commit to annual eye exams.  

• Wear protective U.V. rays’ lenses daily — no exception.

• Use a drop-aid device to ensure that eye drops are placed efficiently in the eye(s). 

• Know the signs of Hypotension — persistently low blood pressures may exacerbate disease progression. 

• Avoid taking blood pressure-lowering medications in the evening before bedtime — lower nocturnal blood pressures may increase the risk of glaucoma progression.

• Tell your ophthalmologist if you medicate with MMJ.

• For eye drop tips, visit - https://www.glaucoma.org/treatment/eyedrop-tips.php

 FOR ADDITIONAL INFORMATION ON GLAUCOMA: 

· The Glaucoma Research Foundation - https://www.glaucoma.org/glaucoma/

· National Eye Institute - https://www.nei.nih.gov/

REFERENCES 

Tomida I, Pertwee RG, Azuara-Blanco A. Cannabinoids and glaucoma. British Journal of Ophthalmology 2004;88:708-713. 

Sun, X, Xu, CS, Chad, N, et al. Marijuana for Glaucoma: A Recipe for Disaster or Treatment? Yale Journal of Biology and Medicine 88 (2015), pp.265-269.

Flach AJ. Delta-9-tetrahydrocannabinol (THC) in the treatment of end-stage open-angle glaucoma. Trans Am Ophthalmol Soc. 2002;100:215-224.

Hepler RS, Frank IR. Marihuana smoking and intraocular pressure. JAMA. 1971 Sep 6;217(10):1392. PMID: 5109652

Miller S, Daily L, Leishman E, Bradshaw H, Straiker A. Δ9-Tetrahydrocannabinol and Cannabidiol Differentially Regulate Intraocular Pressure. Invest Ophthalmol Vis Sci. 2018 Dec 3;59(15):5904-5911. doi: 10.1167/iovs.18-24838. PMID: 30550613; PMCID: PMC6295937.

 Yazulla S. Endocannabinoids in the retina: from marijuana to neuroprotection. Progress in retinal and eye research. 2008 Sep 1;27(5):501-26

Tomida I, Pertwee RG, Azuara-Blanco A. Cannabinoids and glaucoma. Br J Ophthalmol. 2004 May;88(5):708-13. DOI: 10.1136/bjo.2003.032250. PMID: 15090428; PMCID: PMC1772142.

https://www.aliceolearyrandall.com/ Accessed January 27, 2022

Colasanti BK, Craig CR, Allara RD. Intraocular pressure, ocular toxicity, and neurotoxicity after administration of cannabinol or cannabigerol. Experimental eye research. 1984 Sep 1;39(3):251-9.

Melton R, Thomas R. Ophthalmic Drug Guide. Review of Optometry. https://www.reviewofoptometry.com/publications/ro0516-ophthalmic-drug-guide. Accessed January 25, 2022.

BrightFocusFoundation. Glaucoma: Facts and Figures website. https://www.brightfocus.org/glaucoma/article/glaucoma-facts-figuresexternal. Accessed January 26, 2022.

This information is designed for educational purposes only. It would be best not to rely on this information as a substitute for or replace professional medical advice, diagnosis, or treatment. Suppose you have any concerns or questions about your health. In that case, you should always consult with a physician or other healthcare professional. The FDA has not evaluated this information, nor is it intended to diagnose, cure or prevent any disease or disorder of any kind.