Why Marijuana Is Not a Practical Treatment for Glaucoma | Research

The takeaway

While marijuana lowers eye pressure, the effect lasts only 3-4 hours, requiring use 6-8 times daily, which would cause significant adverse effects and potential cannabis dependence, making it impractical for most glaucoma patients.

Read this if you have glaucoma and are considering marijuana as a treatment option.

IOP effect lasts 3-4 hours; would need 6-8 doses daily

What the researchers found

This review examined whether marijuana or cannabinoid-based drugs could treat glaucoma. While marijuana does lower intraocular pressure (IOP), the effect only lasts 3-4 hours, meaning patients would need to use it 6-8 times daily to maintain pressure reduction.

Such frequent use would produce significant adverse effects including cognitive impairment, psychomotor slowing, and potential progression toward cannabis use disorder with withdrawal symptoms upon cessation.

The review concluded that the deleterious effects of marijuana outweigh the benefits of its IOP-lowering capacity in most glaucoma patients. Only under extremely rare circumstances might a few categories of patients be candidates. The authors called for research into focused cannabinoid delivery directly to the eye.

Why it matters

Glaucoma is one of the most commonly cited reasons for medical marijuana use, but this review demonstrates that the pharmacokinetics make it impractical as a glaucoma treatment and highlights the need for targeted eye-specific delivery.

The numbers in context

IOP-lowering effect lasts 3-4 hours; would require 6-8 daily doses; adverse effects include cognitive impairment, psychomotor effects, CUD risk, and withdrawal symptoms

How the study worked

Narrative review of published evidence on marijuana and cannabinoids for glaucoma treatment, examining efficacy, duration of action, and adverse effects.

What this study cannot tell us

Narrative review. Did not systematically assess all available evidence. Focused primarily on smoked and oral marijuana rather than novel delivery methods. The "extremely rare" candidates for marijuana-based glaucoma treatment were not well defined.

How to read the evidence

Narrative review providing a clear pharmacological argument against practical use, supported by known drug properties and adverse effect profiles.

When this study was published

Published in 2015. Research into topical cannabinoid eye drops has continued, though no clinically viable product has emerged.

The bigger picture

The marijuana-glaucoma connection is more myth than medicine in its current form. Effective glaucoma treatment requires sustained, 24-hour IOP control, which smoked or oral marijuana cannot provide. Topical cannabinoid eye drops remain an area of research interest.

Questions still open

Could cannabinoid eye drops provide sustained IOP lowering without systemic effects? Would slow-release cannabinoid formulations change the calculus? Are there specific cannabinoids more effective for IOP reduction?

Common questions

Can marijuana treat glaucoma?

Marijuana does lower eye pressure, but only for 3-4 hours per dose. Effective glaucoma treatment requires sustained pressure control, which would mean using marijuana 6-8 times daily. The cognitive, psychological, and addiction-related side effects of this frequent use make it impractical for most patients.

Are there better ways to use cannabinoids for glaucoma?

The review called for research into focused cannabinoid delivery directly to the eye, such as eye drops. This could potentially provide IOP reduction without systemic side effects, but no such product has been successfully developed.

Read the original research

Marijuana for Glaucoma: A Recipe for Disaster or Treatment?

The Yale journal of biology and medicine, 88(3), 265-9

View on PubMed ↗

Citation

Sun, Xiaoshen; Xu, Chaoying S; Chadha, Nisha; Chen, Allshine; Liu, Ji. (2015). Marijuana for Glaucoma: A Recipe for Disaster or Treatment?. The Yale journal of biology and medicine, 88(3), 265-9.