Individualized treatment for macular degeneration
By Sasha L Radford, OD
If you’re over the age of 60, you should be aware of recent advances in the treatment of age-related macular degeneration, whether it pertains to you or someone you love.
Recent research has changed the way eye care providers can treat age-related macular degeneration (AMD), one of the most common causes of vision loss in older adults. While there is no cure for AMD, there are treatments. Genetic analysis can be done to guide treatment for each individual with a simple cheek swab.
AMD is a disease of the macula, the part of the retina responsible for sharp central vision which we use to read, drive, recognize faces, and distinguish colors. Those most at risk of developing AMD are Caucasians, those with a family history of the disease, and those who smoke. Patients are advised to take “eye vitamins” but due to the many varieties available, often wind up purchasing whatever is on sale, despite eye doctors’ best efforts to recommend the best formula.
There are two types of macular degeneration: “wet” and “dry”. The wet form occurs when blood vessels under the macula leak; central vision loss can be quick and devastating. The dry form occurs when the tissue under the macula becomes unhealthy. There are no leaking blood vessels in this form but it can also lead to central vision loss, although at a slower pace than the wet form.
Treating the wet form of AMD requires injections by a retina specialist to stop the leaking vessels. Vision may or may not be fully recovered, but the procedure usually stops the damage in its tracks.
Treating the dry form of AMD is more difficult because there is no surgical procedure available. However, certain vitamins and supplements can slow its progression. For several years, eye care providers have been recommending a specific vitamin formulation which can slow the risk of progression for patients with moderate signs of AMD. This formula is comprised of high doses of vitamins C, E, beta-carotene, and zinc. This combination does have its limitations: high doses of beta-carotene increase the risk of lung cancer in smokers, and many people are intolerant to high amounts of zinc. A more recent formula replaces beta-carotene with the nutrients lutein and zeaxanthin which is safer for smokers.
Now we know that one supplement does not fit all and that prescribing the best nutritional supplement for patients with AMD depends on their genetic makeup. The risk of developing AMD depends heavily upon family history – there are 15 different genetic variants which can result in the disease. Not only do these genes determine how likely someone is to have vision loss from AMD, the different genetic types also determine what supplements are best to slow AMD’s progression.
Patients with AMD fall into three different categories, each requiring a different supplement to slow their AMD progression: those who should take antioxidants with zinc and those who should take one or the other but not both. The progression of AMD can actually increase when patients are taking a formula that does not correspond to their genetic makeup.
The genetic test, known as VitaRisk, can be given by eye care providers and consists of a simple swab of the inner cheek to collect a DNA sample. Results consist of a description of individual genetic markers associated with AMD, a 10 year risk analysis – how likely the patient will progress to vision loss in the next ten years – and a recommendation for appropriate nutritional supplements based on the genetic profile.
VitaRisk is covered by most medical insurance when there are already early signs of the disease. With these results, your eye care provider can eliminate the confusion about “eye vitamins” and help you choose the best formula individualized to your own genes. Find out more at macularisk.com.