Can CBD Help with Macular Degeneration?
- CBD may be used to treat macular degeneration because of its reported neuroprotective properties that could benefit patients with retinal disorders(1).
- Studies have revealed that CBD reduced retinal cell death(2) and decreased retinal inflammation in rats(3).
- Researchers believe that cannabidiol interacts with various structures in the body, such as the adenosine receptors(4), to exert its therapeutic effects.
- However, no human clinical trials on macular degeneration and CBD have been completed to prove that the compound can effectively treat the condition.
- Patients are advised to talk to a doctor, especially one with medical cannabis experience, before deciding to purchase any CBD product.
Why People Are Turning to CBD for Macular Degeneration
Cannabidiol (CBD) could be used to treat macular degeneration due to its reported neuroprotective effects on retinal neurodegenerative diseases(5).
Research in 2003 revealed that CBD reduced cell death in rat retinas injected with a substance that copied the effects of glaucoma. The study was reportedly the first demonstration of cannabidiol as a retinal neuroprotectant in vivo(6).
Researchers in a 2006 study learned that CBD treatment significantly reduced oxidative stress and prevented retinal cell death in diabetic rats(7).
In another study, cannabidiol was shown to decrease retinal inflammation in rats by blocking cells and structures responsible for neuroinflammation(8).
Although these findings shed a positive light on CBD as a potential treatment for macular degeneration, all of the current research studies were performed on animals.
There have been no human clinical trials completed to prove that cannabidiol can effectively treat this eye condition.
How CBD Oil Works to Help with Macular Degeneration
A study published in 2008 investigated the role of adenosine signaling in retinal inflammation and how CBD could potentially modulate this pathway. The results showed that adenosine receptors are abundant in rat retinal cells(9).
The researchers confirmed that the activation of these receptors plays a crucial role in anti-inflammation in the retina. They also added that CBD inhibited adenosine uptake, an action associated with inflammation(10).
Another potential target for treating eye diseases is through the endocannabinoid system (ECS), a part of the body that regulates functions involving the nervous system and the immune system. The primary cannabinoid receptors of the ECS (CB1 and CB2) are both present in the retina(11).
CBD has been found to interact with these receptors, even at reasonably low concentrations(12). Its affinity with the CB2 receptor is believed to play a part in CBD’s anti-inflammatory properties.
The Pros and Cons of CBD Oil for Macular Degeneration
- Several clinical trials on animals have shown that cannabidiol could be a potential treatment for retinal diseases due to its supposed neuroprotective effects(13).
- Researchers consider CBD as a potential retinal neuroprotectant because of its reported ability to reduce cell death in rat retinas subjected to a substance that mimicked the effects of glaucoma(14).
- Hemp-derived cannabidiol is now legal, according to the United States 2018 Farm Bill(15). Americans can buy and use CBD products in most states.
- CBD is a non-psychotropic compound of cannabis plants. Although CBD is also found in marijuana, it is THC that causes the mind-altering effects.
- The U.S. Food and Drug Administration supports research on cannabidiol and other cannabis products(16). The agency also recognizes the potential benefits of CBD.
- There are no human clinical studies that prove CBD to be an effective treatment for macular degeneration.
- Most of the studies on cannabidiol have been performed on animal models, making it difficult to determine if it can be used to treat certain medical conditions.
- Cannabidiol is not a risk-free substance. Human studies have shown CBD consumption to be associated with drug interactions, diarrhea, fatigue, and vomiting(17).
- Health insurance firms in the United States do not cover CBD or medical marijuana, even if prescribed by a physician.
How CBD Oil Compares to Alternative Treatments for Macular Degeneration
A study on age-related macular degeneration (AMD) analyzed dietary supplements as a potential approach to delay the development of the condition. A formula that contained vitamin C, vitamin E, and beta-carotene have been mentioned in the assessment(18).
One study showed that using a combination of these nutrients could significantly decrease the chances of progression to an advanced type of macular degeneration(19).
A study published in the journal Antioxidants stated that vitamin C and E are effective nutrients in minimizing the risk of developing macular degeneration. They also stated that carotenoids, such as beta-carotene, are known for their protective effects against eye diseases and macular degeneration(20).
Similarly, cannabidiol is said to have antioxidant and anti-inflammatory properties that could be used for many health conditions(21).
One study claimed that CBD is a more effective neuroprotective antioxidant than vitamin C and E(22).
How to Choose the Right CBD for Macular Degeneration
The three variants of CBD that users can purchase today are full-spectrum, broad-spectrum, and isolate.
Full-spectrum CBD is perhaps the most well-known of the three. This form of cannabidiol has all of the natural components of cannabis plants, including THC, flavonoids, and terpenes.
High-quality full-spectrum CBD has high cannabidiol content and small amounts of the other compounds present. Full-spectrum CBD is also known for the “entourage effect,” a synergism wherein all cannabis constituents are more efficient when taken together(23).
The second variant of CBD is called broad-spectrum. This type is very similar to full-spectrum, in that it also has various cannabinoids present.
The main difference between the two is that broad-spectrum CBD does not contain THC. Some people prefer broad-spectrum because they wish to avoid the psychotropic effects of tetrahydrocannabinol.
The last form of CBD is the isolate. CBD isolates are made of pure cannabidiol and are often sold as crystals or powder.
Due to how pure they are, CBD isolate products do not have a distinct taste or smell.
Of the three, full-spectrum CBD oil is perhaps the most potent type of cannabidiol because of the entourage effect.
No matter the form one chooses, it is essential to acquire the highest quality CBD products available.
The following are some tips to assist users in obtaining the best CBD products:
- Acquire a lab report or certificate of analysis (COA) for the chosen item. A COA is a document detailing and showing the exact content of the CBD product.
- Hemp plants are the best sources of getting high-quality cannabidiol. Be wary of brands that do not use industrial hemp in creating their CBD products.
- Know the legalities about buying and using CBD in the various states, particularly where one decides to consume the compound.
- Testimonials and reviews can help users select a reputable CBD brand for their needs. When buying from a dispensary, ensure that the establishment is authorized to sell cannabidiol products.
- Consult a medical expert before buying any CBD product. A doctor who is experienced in medical cannabis is highly recommended.
CBD Dosage for Macular Degeneration
As of this writing, the FDA has not released official guidelines concerning CBD dosage. This predicament makes it hard for users to know the proper dose range that could benefit patients with retinal disorders.
However, one can look at clinical trials in the past to identify a safe amount of CBD to take.
In a 2017 study, healthy volunteers, who were given 600 mg of cannabidiol, experienced the desired effect of the compound without adverse side effects.
Meanwhile, taking as much as 1,500 mg of CBD each day has been reported to be well-tolerated in human subjects(24).
First-time users may also talk to a medical expert to know a suitable dose range for CBD.
How to Take CBD Oil for Macular Degeneration
CBD in the form of edibles is one of the easiest ways to consume cannabidiol. Most brands sell CBD gummies that come in various flavors.
There are also CBD capsules and tablets that can be taken in the same manner as supplements.
For users looking to apply CBD immediately, sublingual administration is the preferred method. Taking substances under the tongue has proven to be a faster way compared to the traditional oral route(25).
CBD tinctures also have droppers that make it easier for people to measure how much of the compound they are going to take.
Inhaling cannabidiol by way of vaping devices is also another quick way of taking CBD because of its high bioavailability(26). Bioavailability is the measurement of how much a substance enters the body successfully.
What is Macular Degeneration?
Age-related macular degeneration, also called AMD, is an eye disorder that causes blurring of the sharp, central vision required for many activities. The condition affects the area of the eye known as the macula and is prevalent in older adults.
Some AMD patients may experience minimal peripheral vision loss or none at all.
AMD happens frequently and is a leading cause of vision loss for individuals above the age of fifty(28). Although AMD does not result in complete blindness, it can take away much of a person’s central vision, making it very difficult to see.
In some cases, macular degeneration develops slowly. People with early stages of AMD may not always experience vision loss right away.
For others, AMD progresses rapidly and can lead to the loss of vision in one eye.
Wet and dry AMD are the two forms of macular degeneration. Wet AMD is when abnormal blood vessel growth in the eye starts to leak and cause damage, leading to rapid loss of central vision. On the other hand, dry AMD progresses slowly, but can generally affect both eyes(29).
The causes of macular degeneration remain unclear. However, experts believe environmental factors, such as smoking, alcohol, and diet, and heredity plays a role in AMD.
A person with dry macular degeneration may experience visual impairments, reduced central vision in one or both eyes, and difficulty in adjusting to low light levels.
In wet macular degeneration, abnormal blood vessels begin to leak blood or fluid into the macula. This leakage leads to blurred vision or the development of a blind spot within a person’s visual field.
Macular degeneration has three stages:
- Early-stage AMD – Presence of medium-sized drusen deposits or deposits of dead cells in the retina. An individual with early-stage AMD does not experience pigment changes and vision loss.
- Intermediate AMD – Presence of large drusen deposits and significant pigment changes. Although most do not experience any other problems, mild vision loss is a possibility.
- Late-stage AMD – A person has dry or wet macular degeneration that leads to vision loss.
There are several factors involved before the disease can progress to the late-stage of macular degeneration. The size of the deposits that are formed in the retina is one of them(30).
Approximately one out of three individuals with small yellow deposits of drusen begin to experience vision problems within five years. Meanwhile, fifty out of a hundred people with large drusen develop late-stage AMD and vision loss within five years.
How is Macular Degeneration Treated?
Similar to glaucoma patients, people with dry AMD can only rely on treatments to alleviate the symptoms of their condition.
Wet macular degeneration is generally treated using drugs that are injected directly into the eye to stop blood vessel growth. This medication is known as an anti-vascular endothelial growth factor (anti-VEGF) and is applied to the VEGF pathways.
Although the treatment does not cure AMD, it is capable of stopping or slowing down its progression. Some individuals experience vision improvements during treatment.
However, repeated eye injections (Lucentis and Avastin) have been associated with increased intraocular pressure (eye pressure)(31).
Photodynamic therapy is sometimes used to treat AMD. This method is a two-step process wherein a laser is directed to the affected area to seal and prevent the progression of abnormal blood vessels.
Compared to anti-VEGF drugs, patients taking photodynamic therapy may continue to experience vision loss within six months of treatment. Their condition eventually stabilizes, stopping the eye from progressing to severe vision loss.
Laser photocoagulation is another approach that uses a concentrated beam of heated light. This laser is directed to a part of the retina to destroy and seal any leaky blood vessels.
However, there is a fifty percent chance for AMD to recur after laser photocoagulation. That is why close monitoring by way of an expert ophthalmologist is necessary.
Certain dietary supplements are said to help slow down the progression of the disease. Taking vitamins and minerals, such as vitamin C, vitamin E, beta-carotene, zinc, copper, and lutein, could be beneficial for AMD patients.
Many of these vitamins can be found in green, leafy vegetables.
Patients with macular degeneration are advised to avoid highly processed foods and partially hydrogenated fats. Fat-filled snacks may increase the risk of developing advanced AMD.
Promising New Treatments for Macular Degeneration
Below are some of the upcoming treatments for the wet and dry forms of AMD.
- Gene therapy – This type of treatment offers a promising alternative to the constant eye injections to counteract VEGF. This therapy aims to provide patients with a one-and-done treatment by helping the eye create its own anti-VEGF medicine.
- Port delivery system – This refillable device stores anti-VEGF drugs that are inserted in the wall of the eye through surgery. Its purpose is to continuously release anti-VEGF substances in the eye, which can last for up to two years.
- Eye drops – Eye drop products for AMD have already been tested in animal trials. Once approved, these drops could become the first at-home solution to help with macular degeneration.
- Oral tablets – Anti-VEGF drugs as pills have already entered clinical trials. Early results suggest that the medication may be used to reduce or eliminate eye injections.
- Combination drug treatments – Mixing drugs that are already out on the market may help treat wet macular degeneration. Scientists are experimenting with combination medicines to find a solution that is more effective than the standard treatments.
- Stem cell therapies – Using stem cells, doctors could replace the cells lost due to retinal damage in macular degeneration. Although having been tested only in small clinical trials, the results thus far are promising.
- APL-2 – This injected medication is intended to slow the disease by saving retinal cells from destruction. The drug is currently being tested and is still a few years away from being available to the public.
- Oracea – This oral antibiotic is currently being tested for its anti-inflammatory properties that could benefit patients with geographic atrophy, an advanced form of AMD.
- Zimura – This eye injection is meant to slow the progression of geographic atrophy in patients with late-stage macular degeneration.
Cannabidiol has the potential to treat age-related macular degeneration because of its purported neuroprotective effects on retinal diseases.
Several studies have shown that CBD may reduce cell death and oxidative stress in animal retinas, which are conditions that occur during AMD.
Despite the positive findings, there are no clinical trials that directly involve CBD as a treatment for macular degeneration. There is also a lack of human clinical trials to prove that cannabidiol can effectively be used for AMD.
Macular degeneration is an incurable disease affecting the central part of the retina. People, especially older adults, are advised to consume supplements rich in specific vitamins and minerals to prevent or delay its onset.
Although there is no evidence that cannabidiol can improve vision, it offers antioxidant properties similar to these supplements that could be beneficial for eye health.
People need to consult a doctor first before deciding to take cannabidiol for any condition.
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