Some studies suggest that marijuana can increase optic nerve damage. Cannabis use decreases blood flow throughout the body. If the optic nerve does not receive enough oxygen through the bloodstream, it will begin to die, which will lead to further vision loss.
Today, there are new methods of ingesting medical cannabis that could be less addictive. For example, lozenges, topical oils, and creams have all been developed to reduce the risk of getting high while benefitting from potential medical effects.
Mood problems can also arise. You may become more anxious or aggressive when you are not intoxicated.
Eye Doctors Understand the Best Course of Glaucoma Treatment
Unfortunately, these newer methods of medical marijuana use do not work to lower intraocular pressure. A study found that eye drops containing THC did not lower intraocular pressure at all. Another study found that smoking marijuana lowered intraocular pressure, and the amount of cannabis ingested would lower IOP in measurable ways, but ingesting more cannabis would not lead to effects that lasted longer. The body still metabolized THC’s peak effects in three to four hours.
When used on a long-term basis, marijuana changes your brain’s development and alters structures in the brain associated with the reward system. Some medical studies have found that consistent, long-term abuse of this drug lowers intelligence and cognitive abilities, leads to a significant decline in general knowledge, and can lead to memory problems.
Because the effects on IOP last only a few hours, medical marijuana does not help to maintain stable low eye pressure, which is necessary to reduce damage to the optic nerve.
California became the first state to legalize marijuana in any form, in 1996. Glaucoma treatment was cited as one of the potential conditions that medical marijuana could help.
Marijuana is legal for medical use in 30 US states and for recreational use in 9 US States. It’s legal across Canada for recreational use. Despite the relaxed attitude around marijuana, it is still classified by the federal Drug Enforcement Agency as a Schedule I controlled substance (the same category as heroin and LSD ).
While marijuana does lower IOP, it has major drawbacks as a treatment for a chronic, long-term, disease like glaucoma:
Does Marijuana Lower Intraocular Pressure?
New evidence has emerged showing that parts of the cannabis plant, specifically cannabidiol (CBD), the non-intoxicating, trendy component, may actually worsen glaucoma symptoms. Researchers at Indiana University published a study in the journal Investigative Ophthalmology & Visual Science that shows CBD increases pressure in the eye. This is problematic, they say, considering that CBD has become such a household name in American culture that many people, some of which may have or be at risk for glaucoma, are using it haphazardly as a natural, harmless medicine. But in reality, CBD could be destroying their overall eye health.
As marijuana use becomes more accepted and increasingly legalized, glaucoma patients frequently ask if marijuana can really treat glaucoma. We need to explain some truths and dispel some myths.
Marijuana can cause permanent lung damage when smoked, and possible permanent adverse effects on cognition and mental health. With regular use, tolerance to the eye pressure-lowering effects develops, meaning that increasing drug levels would be required to prevent progression of glaucoma. Moreover, lack of regulation and quality control makes efficacy and safety of marijuana unpredictable. Research efforts to develop THC eyedrops that can effectively lower eye pressure while minimizing side effects are being studied, but have not yet been successful.
Often touted as a magical elixir, CBD is being marketing as a treatment for just about everything, including anxiety, insomnia, pain, and even cancer. According to AARP, baby boomers are fueling the popularity of CBD and using it as a treatment for pain, arthritis and other age-related health problems.
For the study, researchers tested an eye drop in rats that contained CBD. They found that the CBD drops raised pressure inside the eyes by 18% for at least four hours after the drops were applied. They also tested eye drops that contained only THC, with no CBD, and found that eye pressure decreased temporarily by up to 30% within eight hours.
The ophthalmologists at Baptist Eye Surgeons continue to recommend that patients stick with their currently prescribed treatment of oral medications or eye drops, and come in for regular visits so that their eye pressure and long-term care can be monitored.
Glaucoma, however, has been taken off the list of conditions that may benefit from CBD. The American Academy of Ophthalmology recently reported that a new study proved CBD may worsen glaucoma, which is a leading cause of blindness in the U.S.
For people who don’t have glaucoma and are considering using CBD for other conditions, it’s important to note that research of CBD is in its infancy, and the purity and dosage of some CBD consumer products may not reliable. In addition, CBD can have negative interactions with many medications, so patients with any eye conditions or diseases should talk to their ophthalmologists before taking it.