With the talk of cannabis constantly growing, we get a number of patients who ask about marijuana and glaucoma. We would like to shed some light on the reality of the situation and have asked Dr. Orlando, founder of Columbus Ophthalmology Associates and expert cataract surgeon to shed some light on the reality of using marijuana to treat glaucoma.
But first, let’s start with what is glaucoma?
Glaucoma is a common sight-threatening disease that can cause damage to the optic nerve damage, the delicate cable-like structure that connects the eye to the brain. Most often, the damage is a result of chronic high pressure within the eye that slowly destroys the nerve fibers from the inside of the nerve outward. The loss of optic nerve fibers is not reversible but at detection and with treatment, the progression of the disease can be stopped.
Now that we’re clear about glaucoma, we’ve asked Dr. Orlando to give us a glimpse of what he shares with his patients about glaucoma and the use of cannabis.
“Last year Ohio voted to legalize medical marijuana and almost immediately patients began to ask if it would help them with their glaucoma. So far, Ohio has not determined what medical conditions and in what clinical circumstance cannabis can be used. However, the drug has been studied for many years by ophthalmologists as public opinion has more or less approved it’s use for glaucoma. But the scientific reality is that it does not really work as treatment for this potentially blinding disorder. First of all, one must understand that glaucoma is a very multi-faceted and challenging disease that can present in a variety of ways. Basically, the internal pressure of the eye damages the delicate optic nerve which connects the eye to the brain where images are created. Eye doctors measure this pressure as part of their routine eye exam and look for elevation that is above the normal of 20mmHg. However, damage can occur even with pressure readings lower than 20 and so the optic nerve itself needs evaluation with a variety of tests that can pick up early signs of damage. When diagnosed, the glaucoma specialist will set a “target pressure” and begin the most appropriate treatment to lower the readings to that point. Follow up visits are required in order to make sure there is no further damage to the nerve with the initial medical therapy. In some cases, a special laser known as the SLT will open the internal canals and allow the pressure to drop if topical drops do not control the pressure readings at a safe level. In extreme cases, microsurgery will create a drain from inside to drop the pressure and prevent further damage.
Scientific research on the use of cannabis for glaucoma treatment has been done for over 30 years. Initial studies done with patients smoking the drug found pressure readings that dropped around 25% but the effect lasted only 2 to 4 hours. Other studies with oral administration of cannabis extract also showed only a short time frame for lowering of the intra-ocular pressures. Some case reports have showed variable response to the drug in lowering pressures and so the overall consensus is that cannabis is ineffective for long term treatment of glaucoma. There are far more proven effective therapies and the American Glaucoma Society has stated there is no form of cannabis that is recommended for treatment of this disease. The University of Mississippi is currently the only approved site for cannabis research and we will await further studies to see if this can be an effective adjunct to our current treatment options.”
Hopefully this update from Dr. Orlando has helped shed some light on the use of cannabis for the treatment of glaucoma. If you are suffering from glaucoma and would like to speak with a specialist, please call our offices and we will be happy to assist you.