Macular degeneration is a medical condition in which the light sensing cells in the macula malfunction and, over time, cease to work. According to the American Academy of Ophthalmology, it is the leading cause of central vision loss (blindness) in the United States today for those over the age of fifty years. There are two basic types of the disease: Standard Macular Degeneration (MD) and Age Related Macular Degeneration (ARMD), with ARMD being the most common form of the condition. Macular degeneration which is not age related is most commonly caused by an inherited condition. These forms are sometimes called Juvenile macular degeneration (JMD). In macular degeneration the final form results in missing or blurred vision in the central, reading part of vision. The outer, peripheral part of the vision remains intact.
During the early stages of the disease, the neural layers of the retina remain relatively unaffected. This fact makes it a possible target for treatment with a retinal prosthesis, which are currently under development.
Recently, the drug ranibizumab (Lucentis) has been cleared by the FDA for use in the treatment of AMD. Ranibizumab has been shown to not only halt the progession of the disease, but also works to reverse its effects and over time improve the patient's vision. Ranibizumab has been shown to improve vision 3 lines or more in approximately 40% of patients and has a very favorable safety profile.
Bevacizumab (Avastin), a drug approved for use in colon cancer, has been used by ophthalmologists in the treatment of wet macular degeneration, but has only been shown to be effective anecdotally. There is no controlled safety data collection of bevacizumab in AMD. Bevacizumab has been shown to have very serious systemic side effects.