February is Macular Degeneration Awareness Month. Age-related macular degeneration (AMD) is a chronic disease of the macula, which is the part of the retina that gives you your clearest acuity. AMD is the leading cause of blindness in the Western world and, as the population ages, will increase significantly. There are two forms of AMD: dry and wet.
Dry AMD is more common than wet and dry AMD can lead to wet. Dry AMD occurs when cells in the macula begin to break down, causing thinning of the tissue and a gradual decrease in vision. The retina becomes unable to rid itself of its metabolic waste and the waste accumulates in the retina as drusen. This blocks the normal function of the retina.
What are the symptoms of AMD? Wet AMD is caused by the growth of abnormal blood vessels in the retina. These weak blood vessels leak fluid into the retina, leading to a decrease in vision which is more rapid and dramatic than dry AMD. Neither dry AMD nor wet AMD causes total blindness, only a loss of central vision. People with AMD may notice changes in their ability to read books, to see street signs, or to see details on a person’s face. However, they are able to move around safely using their peripheral vision.
- Gradual or rapid loss of central vision
- Distortion of straight lines
- Blurry vision when reading
- Blind spot in or near the central vision
What are the risk factors of AMD?
- Family history
- UV light exposure
- Diets high in sugar and refined carbohydrates
- Excess weight or obesity
- Gender (women are at a higher risk than men)
- Eye color (light colored eyes have a higher risk)
- Race (lighter pigmented individuals are at a higher risk)
- Cardiovascular disease
How is AMD diagnosed?
An optometrist can diagnose AMD during a dilated eye examination using special lenses to view the retina. A thorough patient history, Amsler grid testing, and advanced imaging of the retina can also point to AMD. Early diagnosis of AMD can give a person the opportunity to make diet and lifestyle changes that decrease the risk of progression of the disease.
Controlling AMD with diet:
Numerous studies have shown a relationship between nutrition and AMD. To date, the most significant study is the Age-Related Eye Disease Study (AREDS). AREDS was a large randomized controlled trial that followed over 3,000 participants for seven years and concluded that taking a supplement with specific antioxidants and zinc decreases the risk of progression of AMD in certain patients by as much as 25%. The follow-up study, AREDS-2, is currently assessing the preventative effects of supplementing patients’ diets with high doses of two carotenoids (lutein and zeaxanthin) and omega-3 fatty acids. We recommend that patients at risk for AMD take a specific vitamin supplement and an omega-3 fatty acid supplement. However, a supplement is not a replacement for a healthy diet. The synergy of the nutrients in whole foods has a beneficial effect on our bodies that a supplement cannot replicate. Many other studies have found that diets high in certain nutrients help to reduce the risk of AMD, and that poor diets can increase a person’s risk for developing the disease. The findings of these studies are summarized in the lists below:
Prevention of AMD through diet:
- Eat foods rich in the carotenoids, Lutein (10mg) Zeaxanthin (2mg)
- Ensure your diet is high in vitamin E, beta-carotene and zinc.
- Choose fish with high levels of omega-3 fatty acids
- Engage in higher level of physical activity or exercise
Vitamins for prevention: (sample name brands Preservision, Macutrition)
- Vitamin C 500 mg
- Vitamin E 400IU
- Zinc Oxide 40 mg
- Copper (Cupric Oxide) 2 mg
- Omega 3, DHA 1000 mg, EPA 1000 mg
- Xeazanthin 8mg
- Lutein 20 mg
- A diet with a high glycemic index
- Excess weight and obesity
- UV exposure
What is the current treatment for dry AMD?
The current treatment for dry AMD aims to slow the progression of the disease. If you have dry AMD, you are advised to modify your diet and lifestyle by eating foods rich in specific antioxidants and omega-3 fatty acids, to take AREDS-based ocular vitamins, to wear sunglasses, and to stop smoking.
We advise people with dry AMD to use an Amsler grid on a daily basis. The Amsler grid is a simple test that allows a person to notice subtle changes in vision that can be a sign of progression of dry AMD to wet AMD.
What is the current treatment for wet AMD?
There are several treatment options for wet AMD, depending on the stage of the disease and the location of the abnormal blood vessels. These include laser photocoagulation, photodynamic therapy with Visudyne and anti-VEGF (vaso-endothelial growth factor) injections. To date, the only treatment that has shown an improvement to visual acuity is anti-VEGF injection. Anti-VEGF medications block the protein (VEGF) that is responsible for new blood vessel growth. In wet AMD, these medications help stop the growth of new blood vessels in the retina. They may slow the progression of vision loss and, in some cases, even improve vision. An ophthalmologist (eye surgeon) will inject the medication into the eye. Multiple injections, given on a monthly basis, are often required for treatment to be effective.
- AMD is the leading cause of blindness in the Western world.
- AMD affects central vision only. It does not lead to total blindness.
- There are two types of AMD: dry and wet.
- Dry AMD is more common and less severe than wet AMD. In some cases, dry AMD can progress to wet AMD.
- Antioxidants, carotenoids (lutein and zeaxanthin), omega-3 fatty acids, and diets high in fiber that include whole rains may help to prevent or reduce the risk of progression of AMD.
- People with a family history or signs of early to intermediate AMD are generally advised to take an AREDS-based vitamin supplement, to follow a diet filled with eye foods, and to visit their eye doctor regularly.
- Smoking increases the risk of AMD.
At Unique Optique, Dr. Maria will give you a thorough exam to determine if you show any signs of macular degeneration. Make your yearly appointment now.