Enlightening Eyesight | Cannabis for Glaucoma
As the old saying goes, your eyes are the windows to your soul. Eyesight is often taken for granted until its clarity becomes hindered. With over one million nerve fibers located within your optic nerve bundle. This complex network of neurons is as delicate as it is powerful. Unfortunately, by the year 2020, roughly 79.6 million people throughout the world will experience the horrifying degenerative effects of glaucoma (1). This disease is referred to as a silent condition as its onset is generally slow and comes with few verifiable symptoms. However, if gone untreated, what starts as a minor vision disturbance can lead to serious vision loss, including full blindness (2).
In the quest to avoid vision loss, many glaucoma patients turn to synthetic pharmacological treatments. While these treatment methodologies have a high success rate, our deepening understanding of cannabis and its influence on the human endocannabinoid system has triggered a new form of glaucoma treatments.
Relieving Pressure | The Effects of Cannabis on Glaucoma
Although there are many cutting-edge glaucoma treatments, the only verifiable way to offset the progression and severity of glaucoma is by reducing intraocular pressure, also known as IOP. This is typically accomplished by daily application of prescription eye drops or by invasive surgery (3). However, achieving this same effect isn’t isolated to pharmaceutical treatments.
An innovative study performed in 1971 found that after smoking cannabis, study participants experienced a 25 to 30 percent decrease in IOP. However, this positive affect was relatively short-lived; lasting only three to four hours (4). Further investigation within the early stages of this understanding found effects were not only limited in duration, but also dose dependent (5). Of course, participants experienced undesirable effects derived from the psychoactive properties of THC. Therefore, long term use is unacceptable for many glaucoma patients.
As one can imagine, the use of a plant-based treatment is more desirable than one derived from synthetic compounds. However, based upon the findings in the aforementioned study, to sustain such positive effects a user would need to consume cannabis ever three to four hours. This, along with the psychoactive effects of THC, make cannabis an unattainable treatment option. However, within the past several years, the medical community has isolated a different cannabinoid capable of producing the same IOP-reducing effects minus the “high” experienced by traditional cannabis applications.
CBD | A Solution for Vision Health?
Throughout your optic nerve bundle, CB-1 receptor sites congregate in clusters. While THC seems to have an affinity for CB-1 receptor site, the secondary cannabinoid, CBD (Cannabidiol) appears to positively trigger CB-1 activation. Unlike THC, which directly binds to CB-1 receptors, CBD mediates activation by enhancing the concentration of a naturally-produced endocannabinoid, anandamide (6).
The primary difference between THC and CBD is the latter produces no psychoactive effects. When viewed as a means for reducing IOP, the activation of CB-1 receptors seem to play a direct role (5). Although further research is needed, hypothetical evidence suggests CBD-based treatments may produce desirable effects without the undesirable effects triggered by THC. Therefore, patients may be able to sustain required levels of cannabinoids throughout the day via CBD supplementation.