Seeking natural relief, many patients try cannabis – but are the drawbacks greater than the benefits?
Glaucoma can be a devastating condition for those who suffer from it. Depending on the type of glaucoma, the disease can cause eye pain, halo affects around lighting, nausea, vomiting and gradual loss of vision. Symptoms occur as a result of an increase in the pressure inside the eye, also known as intra-ocular pressure. Left untreated, an increase in this pressure can damage the optic nerve. Unfortunately, by the time most people experience symptoms of glaucoma, some degree of eye damage has already been done.
Patients often manage their glaucoma by taking daily medication in the form of eye drops or pills. Eye drops work topically to help the eye drain better or to help reduce the amount of aqueous humor (fluid produced by the eye). If drops don’t work, pills are used to help further control the production of fluid. In patients for whom medications don’t work or aren’t tolerated, surgery may be an option.
Some glaucoma sufferers who are seeking relief have turned to cannabis to help reduce their symptoms and control the disease. With medical marijuana becoming legally available in an increasing number of places throughout the world, it’s worth taking a look at the mechanisms through which cannabis works to relieve symptoms. It’s also worth considering the reasons why many healthcare professionals still don’t recommend cannabis as a treatment for glaucoma.
Decades of Research
Scientists have been looking at cannabis as a possible glaucoma treatment for many years. Studies from the 1970’s showed that cannabis could lower the intra-ocular pressure in glaucoma patients. Participants who smoked cannabis experienced an increase in heart rate and then a decrease in blood pressure as well as intra-ocular pressure. This was a promising result for those with glaucoma. However, the results were concerning for those with heart conditions in which an increased heart rate could be dangerous.
The National Eye Institute conducted a study specifically looking at the THC in cannabis to see if it was the ingredient responsible for lowering intra-ocular pressure. Researchers found this to be the case, but they also found that THC only works for a few hours. Because of this, they determined that dosing throughout the day was necessary to keep eye pressure levels steady. Due to the psychoactive effects of the drug, this made it impossible for people to use cannabis as a treatment while driving, working outside of the home, and going about many typical daily activities. Scientists continued to experiment with cannabis in various forms, as well as using different methods of delivery.
In 1981, researchers developed mineral oil drops containing a lower level of THC than the cannabis used by the smoking study. The drops could be applied directly to the eyes. They found that the THC could lower systolic blood pressure and intra-ocular pressure without increasing heart rate. The biggest plus? The effects lasted anywhere from 8 to 12 hours.
Studies have continued over the years, with researchers testing out various strains and cannabis compounds. They have discovered that there are cannabinoid receptors inside the eye that may respond to topical application of cannabis compounds. They have also discovered that these receptors control help control intra-ocular pressure because they are responsible for regulating levels of fluid inside the eye. What all of this means for treatment remains to be seen.
How Cannabis Helps (and Exacerbates) Glaucoma
In the meantime, patients who use cannabis to treat their glaucoma report that it helps decrease their eye pain, nausea and vomiting. They insist that since it reduces the pressure inside the eye, it can be used to prevent the disease from progressing. Because cannabis is now available in a variety of strains and different forms of ingestion, patients using it for medical purposes can take it more conveniently and avoid some of the side effects that can occur with smoked cannabis. It’s important for patients to understand that like prescription drops or pills, cannabis doesn’t reverse or cure the disease but can help keep eye pressure levels low while staving off symptoms such as pain and nausea.
A major concern that healthcare professionals in the glaucoma field have about cannabis as a treatment for the disease is that it lowers the blood pressure within the eye, therefore decreasing blood supply to the optic nerve. Many experts say that this can cause damage to an already-stressed optic nerve. Because the point of glaucoma treatment is to stop the progression of eye damage, this makes cannabis a double-edged sword of a treatment. While it can lower eye pressure and works well as a painkiller, it could also potentially speed along the process of vision loss.
For those who do choose to proceed with using cannabis as a treatment for glaucoma, there are other factors to keep in mind. Those with heart conditions should check with their doctors before starting a medical cannabis regime, as the fluctuations in heart rate and blood pressure could be dangerous for some. Cannabis can also react with certain medications, so inform your doctor if you’re preparing to begin a medical cannabis regime. It’s very important to receive advice and guidance from your healthcare professional when treating any sort of chronic disease, even if cannabis isn’t legal in your area and you plan to self-medicate.
As more research is done and more therapies that use cannabinoids become available, researchers will perhaps be able to isolate a way to use cannabis to target the eye in a way that doesn’t affect the optic nerve. Because of the ongoing research, educating yourself and becoming aware of what new studies are being conducted is important – especially if you’re considering (or are already using) cannabis to treat a condition such as glaucoma.