by Matthew LaBrier
Glaucoma refers to a group of eye conditions that lead to damage of the optic nerve.The optic nerve carries visual information from the eye to the brain. Glaucoma is the second leading cause of blindness behind Cataracts.
There are four main types of Glaucoma:
Open-Angle (Chronic) Glaucoma:
The cause is unknown. Pressure in the eyes increases over time, pushing on the optic nerve and retina. Many people live symptom free for years and don't realize they're affected until they begin to lose vision. People of African descent are at particularly high risk.
Symptoms include: Gradual loss of peripheral vision, also known as "tunnel vision"
Angle-Closure (Acute) Glaucoma:
Emergency situation that comes on rapidly. Sudden and severe rise in intraocular pressure in one eye. Can be triggered by certain medications and dilating eye drops.
Symptoms include: cloudy vision, red eye, nausea and vomiting.
Present from birth. Symptoms are often noticed within months of birth. Often hereditary. Almost always treated with surgery.
Symptoms include: enlarged eyes, sensitivity to light, tearing and cloudy vision.
Caused by systemic diseases, eye diseases, and drugs like corticosteroids.
The main goal of treatment is to relieve intraocular pressure. Depending on the type of glaucoma and the particular situation, medication or surgery is how this is achieved. Eye drops, pills, and IV medications (mostly in emergency situations) are also available but can have unintended side effects.
Cannabis has been shown to be effective in the treatment of glaucoma for decades. Cannabinoids, like THC and CBD, have the ability to lower intraocular pressure significantly. The main drawback of marijuana as a means of medicating for glaucoma is that patients generally need to medicate every 3-4 hours. However, with edible consumption, time between doses can be reduced. Research involving synthesized and isolated cannabinoids is currently underway to better utilize cannabis for the treatment of glaucoma. It is possible that a cannabis eye drop could be developed as a means of medicating with longer duration and less side effects.