AMD, or age-related macular degeneration, is not only the leading cause of blindness in the United States, but also the most common underlying cause of general eyesight deterioration in people over age 65. AMD is caused by the gradual deterioration of the central portion of the retina in the eye, known as the macula. Because the retina is the part of the eye that ultimately sends visual information to our brains, deterioration of the macula means that the eye loses its ability to focus itself effectively. In severe cases, it may even result in total loss of vision in the center of the eye.
There are two separate conditions that result in age-related macular degeneration: the "dry" form of AMD, in which the retina simply thins and/or atrophies with age; and the "wet" form, in which a retina that has already experienced the thinning and atrophy associated with the dry form of AMD then begins to form new blood vessels in the layers of the retina. These blood vessels then begin to leak, causing scar tissue to form and the patient's vision to further deteriorate.
AMD can be treated to some degree in order to reduce symptoms, but there is no cure at present. Treatments currently are limited to supplementation of vitamins and minerals to reduce the progression of the disease, and injections of medications - typically angiogenesis inhibitors - to reduce the growth of blood vessels typically associated with the wet form of AMD. Nevertheless, there is currently no cure, and the above treatments can only slow the inevitable progression of the disease.
Induced pluripotent stem cell therapy has shown considerable promise in the treatment of age-related macular degeneration, and in fact there have been several clinical trials in the field of induced pluripotent stem cells and macular degeneration. These trials have focused on regrowing healthy, new retinal tissue to replace deteriorated areas: the first began in 2011 and was sponsored by Advanced Cell Technology/Ocata Therapeutics; there have been several since, showing considerable patient improvement with an even brighter future ahead.