Stem Cell Research & Macular Degeneration

Stem cell therapy is a new prospective treatment for age-related macular degeneration. Both embryonic stem cells and mature skin cells have been part of trials to restore retinal and photoreceptors cells, with the hope that the progress shown in animal testing may prove to save vision in humans.

Age-Related Macular Degeneration

• Age-related macular degeneration, or AMD, is a disease of the eye. The macula, that central part of the retina which is a layer of tissue on the back wall of the eyeball, deteriorates. When this occurs, the central vision, rather than the peripheral vision, is lost, creating a blind spot. The individual is not totally blind, but the blind spot greatly impairs driving or reading, or even recognizing faces. The disease is more common in adults over 50 years old.

"Dry" Macular Degeneration

• Dry macular degeneration, that is without bleeding, is the most common form, and for which there has been no treatment. Symptoms include noting a decrease in the brightness of colors, a blurriness to printed words, needing increasingly bright light to do close work and difficulty recognizing faces.

"Wet" Macular Degeneration

• "Wet" macular degeneration occurs when blood vessels to the side of macula leak and damage central vision. Treatments for "wet" AMD being utilized or investigated as of 2010 include laser and radiation therapy, called photodynamic therapy or PDT; pharmacological agents to stimulate or protect macula cells; gene therapy to rejuvenate cells; even the prospect of "artificial vision" by implanting a retinal chip, but this is still in the investigational stage.

Stem Cell Pros and Cons

• Stem cell transplantation may provide the best success to heal dry macular degeneration, but even the hopes for this method are tempered by the concerns over infection, over the body's acceptance of donor tissue and if rejection would require the use of immunosuppressant drugs to facilitate the transplant.

Stem Cells

• Stem cells are different from other types of cells in that they are able to renew themselves through cell division, and since they are non-specific in character, they can be triggered to become like the specific cells in various organs. This gives stem cells the remarkable ability to rejuvenate the damaged or dead cells in diseased organs.

Regenerating the Diseased Retina

• Human embryonic stem cells and adult stem cells have been developed in laboratory studies to be transformed into patches of cells identical to the damaged retina. Other successful trials involve transplanting the patient's own healthy cells from the corner of the eye to the diseased part of the retina.

Transplant Procedure

• Stem cell patches already prepared, and not transplanted from the same eye, would make the procedure easier to perform and make the operation a viable option for a larger number of people in the early stages of AMD. These "patches" would be injected into the retina at the back of the eye under a local anesthetic, a procedure that would take less than an hour to perform. Much of this research has been performed in the United Kingdom, with support from an international network of physicians and medical facilities.