The Endocannabinoid System May Offer a Two-Pronged Approach to Glaucoma: Pressure Reduction and Nerve Protection | Research

The takeaway

A review of endocannabinoid research in glaucoma found that cannabinoid receptors throughout the visual system can both lower intraocular pressure and protect retinal nerve cells, potentially addressing the two key aspects of glaucoma that current treatments cannot.

Ophthalmologists, glaucoma researchers, and patients with glaucoma interested in emerging therapeutic approaches.

What the researchers found

The endocannabinoid system (including ligands, receptors, and enzymes) is present throughout the visual system from eye to occipital lobe. Cannabinoid receptor activation both lowers intraocular pressure and provides neuroprotection by reducing excitotoxicity and modulating vascular tone — potentially addressing both the pressure and neurodegeneration aspects of glaucoma.

Why it matters

Current glaucoma treatment only targets intraocular pressure, yet many patients still lose vision. There are no approved neuroprotective treatments for glaucoma. If cannabinoid-based therapies can both lower pressure and protect nerve cells, they could revolutionize glaucoma management.

The numbers in context

ECS components found from eye to occipital lobe. Two therapeutic mechanisms identified: IOP-lowering and neuroprotection. Neuroprotection mediated by excitotoxicity reduction and vascular tone changes through cannabinoid receptors.

How the study worked

Literature review searching PubMed, ScienceDirect, and Google Scholar for studies on endocannabinoids and glaucoma, encompassing animal studies, in vitro models, and limited human data. Focused on IOP-lowering and neuroprotective mechanisms.

What this study cannot tell us

Mostly animal and in vitro evidence — human clinical data is scarce. The well-known IOP-lowering effect of cannabis is short-lived and impractical for chronic treatment. No cannabinoid-based glaucoma drug is currently available. Long-term safety of ocular cannabinoid delivery unknown.

How to read the evidence

Narrative review of predominantly preclinical evidence, with limited human studies but strong mechanistic rationale.

When this study was published

Published 2025.

The bigger picture

The recognition that intraocular pressure alone doesn't fully explain glaucoma progression has driven the search for neuroprotective agents. The endocannabinoid system's dual action — addressing both pressure and neurodegeneration — makes it one of the most promising therapeutic targets in glaucoma research.

Questions still open

Could targeted cannabinoid eye drops achieve sustained IOP reduction and neuroprotection? Which cannabinoid receptor (CB1 or CB2) is more important for glaucoma treatment? Would combining cannabinoid and conventional glaucoma therapies produce additive benefits?

Common questions

Can cannabis treat glaucoma?

While cannabis does lower eye pressure temporarily, the effect is too short-lived for practical treatment (lasting only 3–4 hours). The promise lies in developing targeted cannabinoid drugs that could provide sustained pressure reduction AND nerve protection — but these don't exist yet.

Why can't current treatments prevent vision loss in all glaucoma patients?

Current treatments only lower intraocular pressure. But glaucoma also involves nerve cell death from excitotoxicity and vascular damage. The endocannabinoid system is unique because it potentially addresses both pressure and nerve protection simultaneously.

Read the original research

Role of Endocannabinoids in Glaucoma: A Review.

Journal of current glaucoma practice, 19(1), 28-37

View on PubMed ↗Publisher’s paper ↗

Citation

Warjri, Gazella B; Gowtham, Lakshminarayanan; Venkatraman, Vatsalya; Velpandian, Thirumurthy; Dada, Tanuj; Angmo, Dewang. (2025). Role of Endocannabinoids in Glaucoma: A Review.. Journal of current glaucoma practice, 19(1), 28-37. https://doi.org/10.5005/jp-journals-10078-1467