Glaucoma is a condition characterized by increased pressure within the eye. This increased pressure can cause damage to the blood vessels and nerve endings that carry impulses to the optic nerve, and thus impair vision. In chronic, or open-angle glaucoma, the condition results in slowly increasing pressure over time, loss of peripheral vision, and problems seeing in the dark. In acute, or closed-angle glaucoma, the pupil may become dilated and fixed and immediate medical attention is required. The incidence of glaucoma increases with age and has a genetic predisposition.
Standard medical treatments:
Eye drops – Pilocarpine, beta-blockers
Supportive and alternative treatments:
Berries, red wine – flavinoids are anti-inflammatory and anti-oxidant
Avoid caffeine, tea, stimulants, nicotine – they increase eye pressure
Bioflavinoids and Vitamin C
Magnesium – relaxes the blood vessels in the eye
Bilberry leaf – preserves blood vessel integrity
Ginkgo biloba – helps circulation to the eye
Hawthorn – strengthens capillaries
Glaucoma and Cannabis
In 1971, during a systematic investigation of its effects in healthy cannabis users, it was observed that cannabis reduces intraocular pressure. It was found that some derivatives of marijuana lowered the intraocular pressure when taken intravenously, by smoking or orally, but not by topical application to the eye. One problem with taking marijuana to treat glaucoma was that it required constant inhalation, as often as every three hours and the ensuing side effects significantly outweighed the benefits. Cannabis decreases intraocular pressure by an average 25-30%, occasionally up to 50%. Some non-psychotropic cannabinoids, and to a lesser extent, some non-cannabinoid constituents of the hemp plant also decrease intraocular pressure.
The mechanism of action to lower IOP is not known.
Based on reviews by the National Eye Institute (NEI) and the Institute of Medicine and on available scientific evidence, the Task Force on Complementary Therapies believes that “no scientific evidence has been found that demonstrates increased benefits and/or diminished risks of marijuana use to treat glaucoma compared with the wide variety of pharmaceutical agents now available.”
The most significant use of cannabis for glaucoma has been in combination with eye drops, as the effects seem to be additive, in that they operate most likely by different mechanisms. A non-psychoactive extract of cannabis was tested in combination with Timolol eye-drops in patients with high IOP in 1980. They found that the effects of the two medications were complementary and were even effective in some cases where other medications had failed. More testing needs to be done to determine how and when cannabinoids are indicated in the treatment of glaucoma.