Cannabis and Macular Degeneration: Can It Help?
There was a time when people correlated marijuana and the eyes only with dryness, redness and dilated pupils. Time (and some very pinpointed research) has indeed changed this perception for the better. Now there is an overall consensus of the power of cannabis to help with some eye afflictions, especially glaucoma. But what about the BIG ONE that is estimated to affect 6.3 million baby boomers alone by the year 2030? Might cannabinoid therapy be able to help with age-related macular degeneration as well?
What is Macular Degeneration?
According to the American Macular Degeneration Association, macular degeneration (or MD) is the leading cause of vision loss in the country, currently affecting more than 10 million Americans of all ages, more than cataracts and glaucoma combined. Considered an “incurable disease,” MD is caused by the deterioration of the central portion of the retina, i.e. the inside back layer of our eye that first “records” images before they are sent to the optic nerve and brain, where they are translated into scenes we can comprehend. The job of the “macula” is to focus the central vision of the eye. It controls our ability to read, drive and recognize colors and faces. We are able to see details in objects because of the macula as well.
When the cells of the macula begin to deteriorate, the result is that images are not received correctly. In the early and intermediate stages of the disease, blurred vision or waviness may occur. As MD worsens, however, central vision may become lost altogether (although peripheral sight remains).
As we shall see, there are quite a few attributes of cannabis that may correlate it chemically with MD relief. But first, let’s hear about one case where the results of CBD oil in particular on Intermediate MD were crystal clear.
Fabi is a small business owner and active part of the tiny, artist community of Taos, New Mexico. About a year ago, Fabi contracted a tick-born disease. At the suggestion of a friend, Fabi began using a straight CBD oil that she was able to obtain at her local herb store for the condition. She started using the CBD oil internally as instructed by the trained herbalist on staff there.
While she says that her disease symptoms did seem to disappear while she has been on the CBD oil (although she couldn’t say for sure because her symptoms tend to come and go), ANOTHER healthy side effect of CBD was undeniable.
Fabi had also been suffering from macular degeneration for a while (longer than the tick-born illness). About three weeks after starting to use CBD oil, Fabi went to an appointment with her eye doctor. In the beginning months of her MD diagnosis, she received the “standard of care” for someone with her condition: injections of either Lucentis, Avastin or Eylea directly into the eye. All three of these drugs, two of which are off-shoots of colorectal cancer treatment drugs, are designed to inhibit the growth of vascular endothelial growth factor (VEGF). An overabundance of VEGF proteins in the eye area are thought to contribute to abnormal blood vessel growth in the retina, one of the factors contributing to macular degeneration. Because the injections were so unpleasant for her and they weren’t improving the condition, Fabi decided to discontinue them months ago. At the time, she simply resolved to live with the condition, and possibly the loss of her eyesight, as best she could.
That day, her doctor took the usual round of photos of her eyes to see how the condition was progressing. She began with the “wet” right eye, which before that day had been classified as being “Intermediate MD,” meaning some loss of vision and symptoms of MD were clearly present. Her doctor couldn’t believe what she saw.
“The eye doctor treating me for macular degeneration couldn’t believe the photo of the macular,” Fabi said in a recent Facebook post about the visit. “The leaking in the blood vessel that causes lesions, bumps, swelling, etc. (which causes the loss of vision) was mostly gone.”
According to Fabi, her doctor commented: “This can’t be! You haven’t been getting injections so how did the swelling go down?”
Fabi wrote (and confirmed later in a brief interview with UPG), that the only thing she had changed over the course of the three weeks prior to her doctor’s appointment was the introduction of taking CBD oil sublingually (under the tongue). Fabi says that her right eye has gone down from an “Intermediate MD” to an “Early Stage MD” diagnosis. She is now excited to keep up with her CBD oil protocol, which she is confident will clear up the right eye even more and begin to work its magic on the left as time goes on.
“I’m estatic!” says Fabi.
Do Cannabiniods Help Macular Degeneration?
Was it the CBD oil that caused the macular degeneration in Fabi’s right eye to reduce so dramatically in such a short time? Since no studies have been done on cannabinoid therapy and MD directly, scientifically, no one can say for sure. However, there are some interesting correlations between certain characteristics of the healing power of cannabis and the particular mechanisms of macular degeneration:
- There are cannabinoid receptors in the eye area. In a ground-breaking Finnish study on glaucoma conducted in 2002 and published in the journal Pharmacology & Therapeutics, researcher Tomi Järvinena and his team discovered that the eye area has cannabinoid receptors, making this intricately complicated area of the body also a part of the all-encompassing endocannabiniod system (which helps to balance and regulate all other body systems). In the study, smoking cannabis directly was found to lower intraocular pressure in glaucoma patients, but “the discovery of ocular cannabinoid receptors implied an explanation for the induction of hypotension by topical cannabinoid applications.”
- Cannabis is an anti-inflammatory. The fact that cannabis is an anti-inflammatory is nothing new. But cannabidiol has also been shown to be an anti-inflammatory specifically for the retina area, especially when that inflammation is associated with endotoxin exposure and diabetes. Believe it or not, there is a direct correlation between all three of these conditions. Diabetes and macular degeneration often go hand in hand (specifically because of low glutathione levels). Exposure to bacterial endotoxins, on the other hand, can often be an initial cause of MD. And all three of these conditions are instigated by the inflammatory response, which, of course, CBD has proven to be able to mitigate quite effectively.
- Cannibinoids have been shown to inhibit VEGF growth. The whole point of administering the grueling injection of drugs directly into the eye for MD patients is because, supposedly, these drugs have the ability to stop the progression of vascular endothelial growth factor (VEGF). But cannabis has also been shown to do the same thing, with little to no harsh side effects. A 2004 mouse model study of gliomas (brain tumors) conducted by researchers at Comlutense University in Madrid, Spain found that cannabinoids inhibited VEGF pathways, thus slowing tumor growth in the mice. The same effect was also seen in two glioma patients as well.
“Because blockade of the VEGF pathway constitutes one of the most promising anti-tumoral approaches currently available, the present findings provide a novel pharmacological target for cannabinoid-based therapies,” the final report, published in the journal Cancer Research, reported.
Science may someday prove cannabinoid therapy to be the safe, effective, go-to therapy for the millions of Americans affected with macular degeneration. In the meantime, for Fabi (and others like her), perhaps the only proof she needs is the kind she can see with her own two eyes.
Since 2011, John Malanca has been the “go to”, expert and trusted professional in education and information in medical cannabis and the health/wellness sectors. His extensive knowledge of cannabis, the endocannabinoid system, patient needs, and disease care, combined with his upbeat and genuine concern for his audience makes him a favorite among industry hosts.
Cannabis and CBD oil: a new “old” friend in optometry
Optometric training requires learning about bones, muscles, neurology, and the vascular and other systems. But have you heard of the endocannabinoid system (ECS)?
If the answer is no, that’s not surprising.
Although the ECS is critical for human survival, 1,2 cannabinoid receptors weren’t identified until 1964, 1-4 when investigators were trying to locate where marijuana tetrahydrocannabinol (THC) interacted with the brain. It wasn’t until 1988 that the ECS was identified, and 1992 when it was officially acknowledged. 2-4
Humans operate on the parasympathetic and sympathetic system. The parasympathetic system operates under “normal” conditions.
When the body perceives it is under attack, neurochemicals trigger the sympathetic system, activating the “fight or flight” response. 5,6
The ECS, simply put, disengages the sympathetic system. It is responsible for bringing the body back into balance (homeostasis). 2,7 If it doesn’t, the body is faced with unresolved “danger” from the chemicals and processes that are designed to protect it. These chemicals cause inflammation and begin attacking and damaging the body, 7,8,9 which is then labeled as “such and such” disease. Our rampant, epidemic health problems are self-inflicted, 5,7,10 brought on by our diet, lifestyle, and technology. 7,10,11
The ECS (Figure 1) is made up of 2 main receptor sites, CB1 and CB2. 2,4,7,10
CB1 sites are primarily in the brain, heart, and lungs, and modulate the immune response. CB2 receptors are primarily located in the lymph system, detoxification organs, and peripheral systems to break down and clear out the toxic immune system chemicals and debris. 1,3,7,14,24
The body produces its own chemical—anandamide, known as the bliss chemical—to regulate our systems via the ECS. 7,13,14 Unfortunately, in today’s high-stress environment, it can’t create enough to keep up with the demand. 10,14
Eating dark chocolate, exercising, or being “in the zone” are other ways to feed the CB1 and CB2 receptors. 7,14 Cannabidiol (CBD) was removed from livestock feed when it was made schedule 1 in 1941, so it has not been in the food chain for 80 years. CBD is nature’s external equivalent to supplementing the body’s anandamide shortage. 17,18,24
Technically, cannabis is not marijuana; nor is CBD. Cannabis is the botanical name for the common hemp plant, which has been cultivated for industrial purposes for more than 20,000 years. 15,18,24
The medicinal properties of hemp have been utilized for over 10,000 years. 15 The 2 main classes of cannabis are sativa, which is generally stimulating, and indica, which is generally calming. 16,18
Marijuana is a small subset of hemp that has been bred to produce more “high.” Hemp has over 400 different chemicals, with 100 compounds known as cannabinoids, each creating various effects. 16,18
CBD is one of the most prevalent cannabinoids in the hemp plant; it has the most profound, diverse, and beneficial impact. 16,18 The main takeaway is that cannabis is really just the hemp plant, and CBD is not marijuana.
THC and CBD originate from the same compound and have nearly identical chemical structures (Figure 2). 16,22 Depending on the genetic strain, the hemp will have higher or lower THC and CBD levels. When the flower is beginning to bloom, however, growers must test the plants daily because the CBD in the plant will start to become THC. 16,22
At that point, the growers only have 48 hours to harvest their crop. The legal amount for THC to not be considered marijuana is 0.3%. 19,22
The CBD industry wants as high an amount of CBD as possible with the least THC possible. CBD’s profound effects on all bodily functions are not forced—unlike those of pharmaceutical agents—and nor does the chemical have their toxicities or unintended adverse effects (Figure 3). 20,21,24
As of February 2022, 37 states in the United States have legalized marijuana for medical use and 18 have legalized it for recreational purposes .20 The medical and recreational marijuana market is projected to be $30 billion in 2022. 21
Although marijuana still has legal hurdles to overcome, the CBD market is legal in all 50 states. 22 CBD is also available OTC and thus is free from FDA regulations and red tape. 22 The CBD market is projected to be $2 billion in 2022. 23
This projection will result in both good and bad consequences. Because cannabis has been outlawed as a Schedule 1 drug for 80 years, little controlled research has been undertaken and no distinction made between the effects of THC and those of CBD.
Medical benefits, risks
Much of marijuana use is for the high it produces, but there are some documented medical benefits. These include the relief of pain and nausea related to cancer treatments, aiding of sleep issues, reduction of posttraumatic stress disorder symptoms, easing of symptoms in those withdrawing from opioid addiction, and a calming of symptoms of various neurological conditions. 4,24
Unfortunately, according to more recent findings, marijuana does interfere with cognitive ability, 24,29 damages memory function, and destroys brain tissue. It also causes heart attacks—even in younger people with no underlying conditions—may have negative effects on genetics and pregnancy, and, if ingested by vaping or smoking, increases cancer risks. 24 Thus, marijuana is far from risk free.
Of more direct concern to optometrists are the negative effects of marijuana on the visual system. Both photopic and scotopic vision are impaired due to decreased macular and peripheral sensitivity. 24-35
Neurologically, vision processing is compromised, creating selective scotomas and interfering with one’s ability to navigate in the environment. 24,26-28,30,32-35
The eye is both a specialized neurologic receptor and a person’s primary connection to the physical world. It is important for optometrists to be aware of CBD, as eyes are packed with both CB1 and CB2 receptors.
Consider the major 5 medical conditions optometrists often encounter with when working with patients:
1. Cataracts 37
2. Glaucoma 38,39
3. Macular degeneration 41-43
4. Allergies 46
5. Meibomian gland disease 47
Although each is a separate condition, all have inflammation as the root cause due to the eye being threatened by the environment. 35,40 Many treatments are based on treating the symptoms or slowing the progression of damage by interfering with the ocular response process.
CBD works with the body’s natural system to decrease the inflammation process and restore homeostasis, avoiding the long-term results that define disease.
Peer-reviewed, evidence-based science is limited. However, I have heard anecdotally that some patients have experienced better vision with OTC supplementation of CBD and ocular nutraceuticals, backed by macular pigment ocular density (MPOD), optical coherence tomography (OCT), retinal photographs, and acuity. 43,44
We have accepted that ocular “aging” conditions are normal, inevitable, and unstoppable. 45,57 Perhaps traditional medical treatments would be less necessary if we worked with the natural body system designed to minimize those issues.
Beyond ocular conditions, optometrists must step back and look at the larger medical issues facing humanity.
Obesity, diabetes, blood pressure, heart disease, cancer, Alzheimer disease/dementia, autoimmune conditions (lupus), rheumatoid arthritis, fibromyalgia, multiple sclerosis, neurologic disorders, depression, anxiety, panic attacks, migraines, attention-deficit/hyperactivity disorder, and concussions are all inflammation-related processes caused by an increased assault on our physical system.
This has overloaded the natural mechanism eyecare professionals were designed with to maintain health. Optometrists need to learn about ECS and CBD to augment their toolbox for taking care of patients’ well-being. 6,9,36,48,51,55,56,59-63