Cannabis for Glaucoma: A History of Medicine and Activism

Few people know that the modern medical cannabis story began with a 26-year-old American man with glaucoma who found that smoking cannabis improved the symptoms of his disease. This was Robert C. Randall, who won the case in court and became the first “official” medical cannabis patient. As a result, research into the medicinal properties of THC began in the 1970s.

On the occasion of World Glaucoma Day, today on the Cannactiva blog we talk about the history and effectiveness of the use of cannabis in the treatment of glaucoma, with the doctor Fabio Turco and Viola Brugnatelli, from Cannabiscentia.

What is glaucoma?

Glaucomas are a group of eye disorders characterized by progressive damage to the optic nerve, often associated with increased intraocular pressure (IOP), leading to irreversible vision loss. Glaucoma may develop slowly, and the gradual loss of vision may go unnoticed for a prolonged period. Regular eye examinations, including pressure measurement and peripheral vision testing, are essential for those at risk of developing glaucoma.

Glaucoma affects nearly 64 million people worldwide, ranking as the second most common cause of blindness globally. It is particularly prevalent among people over the age of 60, with only half of those affected aware of their condition.

Treatment

The onset of glaucoma is always associated with elevated intraocular pressure, something that was first described in 1622 by the English physician Richard Banister, who stated: “the eye becomes firmer and harder than it should be by nature”.

Treatments for glaucoma focus on medications that reduce intraocular pressure, such as pilocarpine, beta-blockers (timolol), alpha antagonists (brimonidine), prostaglandin F2A analogs (latanoprost) and carbonic anhydrase inhibitors (dorzolamide). When medications are not sufficient, surgical options are considered viable. Despite these treatments, the search for more effective and better tolerated options continues today.

Cannabis Use for Glaucoma: A History of Activism

To explore the efficacy of medical cannabis for glaucoma, we embarked on a journey through the pages of Cannabiscentia’s Handbook of Cannabinology Principles by Viola Brugnatelli and Fabio Turco. This handbook serves as a guide for European healthcare professionals and enthusiasts seeking an in-depth understanding of the medical applications of cannabis.

Cannabis and cannabinoid-based medicines came into use in the 1970s, and since then, cannabis has achieved almost mythical status as a miracle drug for glaucoma. It was then, because of glaucoma, that the modern history of medical cannabis began in 1974.

The Robert Randall case

In the 1970s, Robert C. Randall, a 26-year-old glaucoma patient, discovered that smoking cannabis relieved the symptoms of his disease. Randall faced federal charges for cultivating cannabis, but successfully defended himself through medical necessity. In 1976, the judge ruled in his favor, making him the first “legal” user of medical cannabis.

Randall’s advocacy prompted the Marijuana Research Project in 1974, the first state medical cannabis cultivation program in the U.S., which supplied cannabis to patients until 1992. Randall was a leading activist for cannabis legalization, founded the Alliance for Cannabis Therapeutics and sued the federal government when it wanted to stop giving him access to medical marijuana. This lawsuit and subsequent ruling set an important precedent by legitimizing the medical use of cannabis, helping other patients gain legal access to medical marijuana. This ruling also strengthened the efforts of Randall and other activists to promote laws recognizing the medical benefits of cannabis in several states.

The 1987 ruling was ignored by the Drug Enforcement Administration (DEA ), which continued to maintain a restrictive stance on cannabis, despite legal victories recognizing its medicinal use. In the years that followed, there were multiple efforts to reclassify cannabis and recognize its medical value, but this was consistently rejected by the DEA.

In 1988, the DEA was forced to hold hearings on cannabis rescheduling, prompted by Randall and other activists. DEA Administrative Judge Francis Young urged the rescheduling of cannabis from the drug schedule, stating that “cannabis is one of the safest therapeutically active substances known to mankind.” However, the DEA rejected the ruling and decided to maintain cannabis as a Schedule I substance, stating that it had no accepted medical use and a high potential for abuse. Today we can say that, almost half a century later, in 2024 the United States will approve the reclassification of cannabis, removing it from Schedule I controlled substances.

Randall passed away in 2001, and his legacy includes his valuable contributions to the medical cannabis movement.

Cannabis and Cannabinoids in Glaucoma: Current Research

Mechanism of action

Cannabis and cannabinoids are effective in the treatment of glaucoma by the following routes:

• Some cannabinoids reduce intraocular pressure by interacting with the endocannabinoid system of the eyes, on CB1 receptors.
• They modulate prostanoid synthesis through the cyclooxygenase (COX) pathway, influencing various ocular structures.
• In addition, some cannabinoids exert a neuroprotective effect, protecting retinal ganglion cells by inhibiting the release of glutamate, endothelin-1 and nitric oxide.

Clinical Experience in Personalized Therapy for the Glaucoma Patient: A Prescriber’s Considerations

Dr. Lorenzo Calvi, an Italian anesthesiologist and ethnopharmacologist, challenges the belief that cannabis is not a good treatment for glaucoma based on his practical experience, having treated approximately 150 glaucoma patients. He claims an exceptional success rate of 98%, emphasizing the minimal amount of cannabinoids needed and the absence of psychotropic side effects.

According to Dr. Calvi, cannabis for glaucoma can be used orally, although the best results are obtained with eye drops. Microemulsions or cyclodextrins are used to prepare eye drops, which minimize the problem of the poor water solubility of cannabinoids. Glaucoma treatment is always long-term, so side effects should always be monitored, especially if THC is used.

Dr. Calvi stresses the importance of personalized therapy tailored to each patient, respecting the natural synergy between cannabinoids and terpenes for an effective and clinically safe outcome. He suggests that the positive results observed in the treatment of glaucoma with cannabis may be applicable to other diseases, advocating a collaborative effort between physicians, patients and pharmacists to ensure the success of cannabinoid therapies.

Cannabis and Glaucoma: Conclusions

While the medical cannabis movement was born out of the effectiveness of cannabis in the management of glaucoma symptoms, it is not currently considered a first-line therapeutic option due to its limitations and side effects.

Although cannabinoid medications may be a useful alternative for some patients with glaucoma resistant to conventional treatments, their use is limited by several factors. The short duration of effect, the need for multiple daily doses, and side effects restrict the long-term efficacy and safety of medical cannabis. Conventional treatments, such as eye drops and surgical interventions, remain the most effective and safest options for most glaucoma patients.

The information in this article is derived from Cannabiscentia’s Handbook of Cannabinology Principles, by Viola Brugnatelli and Fabio Turco and Prohibition Partners. A guide on medical cannabis and cannabinoids for healthcare professionals where the European medical cannabis landscape is extensively covered. The second edition is now available. Visit Cannabiscientia for more information.

Note: This is an informational article and is not intended to prevent, diagnose or treat any disease. Its content can complement, but should never replace, the diagnosis or treatment of any disease or symptom. Cannactiva products are not medicines and are intended for external use. There may be new relevant scientific evidence since the date of publication. Consult with your physician before using CBD. The therapeutic approach must always be personalized and depends on the professional assessment.

References and further information

1. Manual of Cannabiscentia Cannabinology Principles, by Viola Brugnatelli and Fabio Turco.
2. Sun X, Xu CS, Chadha N, Chen A, Liu J. Marijuana for Glaucoma: A Recipe for Disaster or Treatment? Yale J Biol Med. 2015 Sep 3;88(3):265-9. PMID: 26339209; PMCID: PMC4553646.
3. Green K. Marijuana smoking vs cannabinoids for glaucoma therapy. Arch Ophthalmol. 1998 Nov;116(11):1433-7. doi: 10.1001/archopht.116.11.1433. PMID: 9823341.
4. Novack GD. Cannabinoids for treatment of glaucoma. Curr Opin Ophthalmol. 2016 Mar;27(2):146-50. doi: 10.1097/ICU.0000000000000242. PMID: 26840343.