Macular degeneration is a retinal disorder that affects central vision. Age-related macular degeneration (AMD) is the most common type of macular degeneration and is the leading cause of legal blindness in people older than 55 years of age. AMD affects more than 15 to 20 million individuals in the United States, a number that—with the rapid aging of the U.S. population—is expected to increase by 50 percent by 2020. Virginia Mason ophthalmologists have many decades of experience treating patients with macular degeneration. Find more information or schedule an appointment with a Virginia Mason Franciscan Health ophthalmologist in Seattle, Federal Way, Issaquah, Kirkland or Lynnwood.
There are two types of age-related macular degeneration: nonexudative (dry) and exudative (wet). Individuals who have the wet form have advanced AMD. Symptoms of the dry form of age-related macular degeneration are usually classified into three categories. The prevalence, incidence, and progression of AMD increase with age.
Your ophthalmologist has a number of tests to choose from to help diagnose age-related macular degeneration.
Treatment for age-related macular degeneration will depend on the type of AMD and how advanced it is. There also are several new therapies, not yet available, that are being investigated for treatment of both the dry and wet form of AMD.
Unfortunately, no treatment currently exists to stop vision loss associated with advanced nonexudative AMD. However, a large National Eye Institute study conducted more than a decade ago investigated the use of antioxidant vitamins and minerals in stopping the progression of the dry form of AMD. The study showed that participants with either intermediate AMD or advanced AMD in one eye benefited the most from the combination treatment of high doses of antioxidant vitamins along with zinc and copper. The rate of development of advanced AMD at five years was reduced by 25 percent and the risk of losing vision of three or more lines of visual acuity was reduced by 19 percent.
The exudative form of age-related macular degeneration was treated for many years with:
However, while blood vessel growth may have slowed, neither treatment prevented vision loss associated with AMD.
Recently, the introduction of VEGF inhibitors—pegaptanib sodium (Macugen) in 2004 and ranibizumab (Lucentis) in 2006—provide more effective treatments for neovascular (wet) AMD. VEGF inhibitors "inhibit" growth factors that cause blood vessel formation in the eye. Patients treated with monthly injections of ranibizumab, for example, have shown a 95 percent incidence of stabilization of vision and an approximate 35 percent incidence of vision improvement. The VEGF inhibitors have become the first-line therapy for treating neovascular AMD.
Another treatment showing benefit is bevacizumab (Avastin), an intravenous treatment for some types of cancers, including metastatic colon, metastatic breast and non-small cell lung cancer. Bevacizumab was investigated first as a systemic intravenous treatment for AMD and then as an intravitreal injection before FDA approval of ranibizumab. Because preliminary reports appeared favorable, ophthalmologists began to use intravitreal bevacizumab to treat AMD.
A recently completed, randomized controlled trial demonstrated equal safety and efficacy of ranibizumab and bevacizumab.