Macular Degeneration
Age-Related Macular Degeneration (AMD) is the leading cause of severe vision loss in people over age 50 in the USA.
There are two major categories. In the “dry” type, abnormal deposits develop under the retina (drusen), atrophy and clumping of pigment occur. Dry AMD tends to progress slowly and can lead to complete loss of central vision. In “wet” macular degeneration, abnormal blood vessels grow beneath the retina, resulting in fluid or blood under the retina. This can occur relatively suddenly, with acute decrease in vision or distortion of vision.
Until recently there was no effective treatment. Photodynamic Therapy (PDT) was approved and offered some advantages over conventional laser. For the first time, wet macular degeneration involving the macular center could be treated without obliterating central vision. Unfortunately, relatively few patients are candidates for PDT. The procedure is expensive and usually requires more than one treatment.
In 2004 Macugen was approved by the FDA as the first medical treatment for AMD. Macugen was developed to block a blood vessel growth factor that had been identified as a causative factor in wet AMD. On the positive side, many more patients are candidates for treatment with Macugen vs PDT. On the negative side, the drug is very expensive, must be injected directly into the eye every 6 weeks, and, while some patients respond very well with significant improvement in vision, most patients continue to lose vision over time. Avastin, also FDA approved in 2004, is an “off label” less expensive for wet AMD. No eye or systemic side effects have been reported with injections of Avastin. The drug seems to be more effective than Macugen and the dosing interval is longer (8-10 weeks). Lucentis, very similar to Avastin, was FDA approved in 2006. This medication, which also seems to be more effective than Macugen, needs to be repeated approximately every 4 weeks.
Although there is a significant genetic component to AMD, recent studies (AREDS for age-related eye disease study) have shown a significant benefit to certain high-dose vitamin and mineral supplements. The increased risk from smoking and the benefit from dark green leafy vegetables is well known. Other studies are ongoing looking at other nutrients such as omega-3 fats (found in some fish and flax seed oil) and xanthines.
The recent advent of medical treatments for wet AMD is very promising. For the first time patients are seeing their vision stabilize or improve. At Associated Eyecare we are excited to offer the most advanced options in diagnosing and treating this complex condition.