Myth or Medicine?
Bottom-line assessment: Cannabis is a legitimate adjunctive therapy for glaucoma. However, cannabis is not effective enough by itself, so glaucoma must be treated by ophthalmologist-prescribed eye drops or surgery when necessary.
In-depth assessment: Glaucoma is the leading cause of blindness in the United States, which is tragic since it is preventable with a healthy lifestyle and regular check-ups with an optometrist or ophthalmologist. Simply put, glaucoma is usually caused by an imbalance of ocular fluid levels and drainage, which builds up enough pressure to damage the optic nerve and parts of the retina.
Symptoms of acute glaucoma (emergency) are vomiting, headache, vision change, and severe eye pain. Symptoms of chronic glaucoma are significantly more subtle, and often begin with gradual loss of peripheral vision progressing to slightly blurred general vision. Halos/rainbows surrounding lights can appear as fluid build-up increases.
Treatment begins with pharmaceutical eyedrops prescribed by an ophthalmologist. Modern ophthalmologic eyedrops and laser surgeries are some of the safest and most effective remedies when compared to other fields of medicine. All glaucoma patients need to be evaluated for these sight-saving therapies.
As an adjunct to these treatments, cannabis has several proven benefits. To elucidate the potential role of cannabis in medicine, one has to navigate through a multitude of worldwide studies and anecdotal accounts, with inherent bias on both sides. Results: For approximately four hours, THC reduces glaucoma symptoms and eye pressure by 20-30%. This is due to the fact that our endocannabinoid system has many receptors in the eye, which help regulate ocular fluid production and drainage (among other functions). Patients with glaucoma have been found to have low levels of naturally occurring endocannabinoids within their eyes. Besides ocular pressure reduction, cannabis also has neuro-protective effects and increases blood flow to the retina and optic nerve.
Limitations to cannabis are not only the legal issues and user-dependent adverse effects, but also the inability to provide 24-hour steady reduction in eye pressure (pharmaceutical eyedrops can accomplish this). It is difficult to reliably produce cannabis eye drops, since cannabis is fat-soluble, and eyedrops are significantly more effective when water-soluble. For now, the safer forms of cannabis are Indica-dominant, low-THC, sublingual drops or transdermal patches. While cannabis can be an effective, sole treatment for some ailments (insomnia, e.g.), cannabis is only an adjunct for glaucoma.
There are also other natural treatments that can be used as adjuncts to ophthalmologic therapy. These remedies can help prevent glaucoma as well: Good nutrition (especially leafy greens), Omega-3s (wild Alaska salmon, fish or algae capsules), Ginkgo Biloba, ACE vitamin (or a whole foods multi-vitamin from a reliable source such as Garden of Life), daily moderate exercise, elimination of processed foods, and avoidance of cigarettes.
I hope this helps to shed some light on this contentious issue,
Brandon Heiberger, MD
HeibergerMD.com 