Macular degeneration is now the most common cause of blindness in people above the age of 60.
Retina San Diego is dedicated to providing state-of-the-art diagnostic imaging and treatments.
WHAT IS DRY MACULAR DEGENERATION?
Age-related Macular Degeneration (AMD) is a degenerative process that affects the central part of the retina called the "macula". The macula is the most critical part of our vision as it is the part of our retina that has the highest density of photoreceptor cells (i.e. the cells that catch the light and change that light energy into chemical energy that can be translated to electrical energy through the nerve of the eye to the brain) and allows us to read and recognize faces.
AMD is divided into Dry Macular Degeneration (Dry AMD) and Wet Macular Degeneration (Wet AMD). Dry AMD which affects 90% of patients with AMD results from the buildup of yellow deposits underneath the retina called drusen.
What are Drusen?
A drusen is a deposit of lipid underneath the retina. Our photoreceptor cells create waste material under the retina which is removed in a normal eye. However in AMD, the waste material is not efficiently removed and with time, the fatty proteins, or lipid waste materials accumulate under the retina and can affect the health of the overlying retina. One out of ten patients with AMD can progress to advanced stages which can significantly affect vision.
What is Geographic Atrophy?
Geographic Atrophy (GA) is an advanced stage of dry AMD in which the retina loses its central photoreceptor cells, and thus its ability to catch the light in the central part of the vision. Patients with GA can have difficulty reading or may need more time finding details in their central vision and as the GA enlarges can lose central vision.
What are the symptoms of AMD?
In its earliest stages, AMD has no symptoms, however along the years it can progress to affect vision thus causing blurry vision or distortions. Patients with very advanced stages can have loss of central vision. However patients with very advanced AMD never become completely blind as their peripheral vision is not affected.
WHAT I CAN DO TO DECREASE MY RISK OF MACULAR DEGENERATION?
The National Institute of Health (NIH) conducted a pivotal study to evaluate whether vitamins could slow the progression of AMD. The Age Related Eye Disease Study (AREDS) found that patients who are at higher risk of developing wet macular degeneration can decrease their chances by at least 25% by taking a formulation of vitamins. Based on the AREDS 2 study, we recommend patients with intermediate AMD or advanced AMD in one eye to take the following formulation of vitamins:
- Vitamin C: 500 mg
- Vitamin E: 400 IU
- Zinc oxide: 80 mg
- Cupric oxide: 2 mg (Copper is used to offset the risk of anemia that can result from the use of Zinc)
- Lutein: 10 mg
- Zeaxanthin: 2 mg
(The Vitamin A/beta-carotene that was initially in the old AREDS 1 formulation was found to increase the risk of lung cancer in patients who have a history of smoking, so the Vitamin A was removed from the new formulation.)
We always recommend that you show the dosage of the vitamins to your primary care physician to ensure they don't interfere with other medications or supplements you may be taking.
Can diet affect AMD?
Diet plays a critical part in AMD as patients with a diet rich in antioxidants have the lowest rates of progression. We recommend a diet rich in green leafy vegetables such as kale, and fruits high in antioxidants such as blueberry, strawberry or acai berry. Omega 3 fatty acids should also be included in a complete diet from sources such as cold-water fish such as salmon, or from flaxseed or flaxseed oil.
What else can I do besides a healthier diet?
Staying physically active and not smoking have also been shown to decrease the risk of progression of AMD.
WHAT IS WET MACULAR DEGENERATION?
Wet AMD results from the growth of abnormal blood vessels underneath and into the retina (known as choroidal neovascularization). It is called "wet AMD" because these abnormal blood vessels can leak or bleed into the retina and in advanced stages lead to scar tissue which can significantly affect the health of the central retina and ultimately your vision. The last decade saw the advent of a new family of medications that can be given to slow the progression of wet AMD and in many cases cause the regression of these abnormal blood vessels or lead to decreased leakage into the retina. The best results are always achieved when treatment is instilled in the beginning stages of the disease which is why it is critical to inform your retina specialist if you notice any changes in your vision.
WHAT ARE THE TREATMENTS FOR WET MACULAR DEGENERATION?
The last decade saw the advent of a new family of medications used in the treatment of wet AMD, called anti-VEGF drugs. Vascular Endothelial Growth Factor (VEGF) is a substance produced within the body that causes the growth of new blood vessels and plays a role in the permeability of the blood vessel walls. Patients with wet AMD have higher levels of VEGF within their eyes which causes the growth of abnormal leaky blood vessels under and into the retina (called choroidal neovascularization) which can bleed and significantly affect central vision. Anti-VEGF drugs inhibit the abnormally high levels of VEGF within the eye and thus cause regression of some of these blood vessels or cause stabilization of the blood vessel wall.
The medication is given with a very small needle after proper anesthesia has been administered to the eye, and the vast majority of patients report little or no discomfort with the treatment. The medication lasts about 1 month and requires continued therapy in the majority of cases. Your retina specialist will start you on a series of 3 monthly therapy sessions and will attempt to increase the interval between injections. Most patients end up requiring continued injection therapy every 1 to 3 months, and a minority of people can stop the therapy.
What are the 3 medications used?
Lucentis (ranibizumab): First anti-VEGF drug to be approved for intraocular use for wet AMD since 2006. Because of its smaller molecule, Lucentis has the least effect on systemic VEGF levels and is cleared faster from the system compared to the other anti-VEGF drugs.
Avastin (bevacizumab): Avastin was developed by the same company as Lucentis however it was approved for certain cancer treatments, but has since then been found to be effective and safe for treatment of wet AMD. It is the drug that is most often used in the U.S. mainly because of its lower cost.
Eylea (aflibercept): Eylea is FDA approved for treatment of wet AMD and has a stronger affinity to VEGF.
HOW CAN I FOLLOW MY AMD IN BETWEEN MY VISITS?
One of the first signs of changes in AMD is the presence of new distortions or missing parts of central vision. Patients will often complain of seeing straight lines as wavy, broken or missing. One of the best tools we recommend our patients with AMD to use is an Amsler grid. Often times, the use of an Amsler grid allows patients to detect early changes from AMD before severe damage has occured, which is critical as treatment of wet AMD is more effective in its earlier stages.
- Cover one eye at a time as each eye needs to be tested separately
- Keep your glasses on if you normally wear glasses
- Keep the grid 14 inches away
- Look directly at the dot in the center
- Inform us immediately if you notice any wavy, blurry lines, blank or dark spots.