Can Cannabis be Used for Glaucoma Treatment?
Going back to the 1970s, studies have shown that cannabinoids can alleviate glaucoma-related symptoms because they lower the intraocular pressure (IOP) and have neuroprotective actions. For example, in 1971, one of the first studies of its kind found ingestion of cannabis lowers IOP by 25 to 30 percent.
Despite the findings from early research, very few ophthalmologists support the use of medical marijuana in patients with early to mid-stage glaucoma. The main issue ophthalmologists have with cannabis is that the potential adverse effects — particularly smoking cannabis — outweigh the short term benefits. For example, smoking can lead to unstable intraocular pressure, thereby increasing risk of permanent vision loss.
Further, because its therapeutic effects on glaucoma are short-term, patients would have to consume cannabis frequently — once every three to four hours. Doctors claim that because glaucoma needs to be treated 24 hours per day, patients would need to consume cannabis six to eight times over the course of a day to achieve consistently lowered IOP levels. Such frequency is hard to maintain and could increase the risk of developing a cannabis use disorder.
However, when it comes to late stage glaucoma, ophthalmologists are more inclined to embrace cannabis as a treatment. At the end stages of glaucoma, it’s less about directly targeting the glaucoma and more about alleviating the accompanying symptoms.
According to ophthalmologist Andrew Bainnson, MD, “We’ve known for some time that medical marijuana is very effective for treating nausea and pain, but not so much for glaucoma,” said Bainnson. “[However,] there are some patients with end stage pain and nausea who may benefit [from medical marijuana], but not from the glaucoma point of view.”
Could Cannabis-Based Treatments Play a Greater Role in the Future?
cannabis based treatments for glaucoma
The body’s own internal cannabinoid system, called the endocannabinoid system (ECS), is one of our most important physiological systems. Nearly every aspect of our health — including inflammation, immune response, neuroprotection, pain modulation — are all dependent on the ECS. Given the vital role of the ECS, particularly in neuroprotection and inflammation, many scientists believe the development of cannabinoid-based medications could be immensely useful in treating (and preventing) glaucoma.
Cannabinoid receptors are prominent in ocular tissues responsible for regulating intraocular pressure. A promising area of research would be to develop cannabinoid-derived medications that target these tissues. Cannabinoid-derived medications could be developed that serve two roles: lowering IOP and protecting retinal cells.
