A collaboration between German and American scientists in New York City has resulted in the invention of a new method for transplanting stem cells into the eyes of patients who suffer from age-related macular degeneration, which is the most frequent cause of blindness. In an animal test, the implanted stem cells survived in the eyes of rabbits for several weeks.
Approximately 4.5 millino people in Germany suffer from age-related macular degeneration (AMD), which causes gradual loss of visual acuity and affects the ability to read, drive a car or do fine work. The center of the vision field becomes blurry as though covered by a veil. This vision loss is a consequence of the death of cells in the retinal pigment epithelium or RPE, which lies are the back of the eye, underneath the neural retina.
Inflammation within the RPE causes AMD. Increased inflammation prevents efficient recycling of metabolic waste products, and the build-up of toxic wastes causes RPE die off. Without the RPE, the photoreceptors in front of the RPE cells that also depend on the RPE to repair the damage suffered from continuous light exposure, begin to die off too.
Presently no cure exists for AMD, but scientists at Bonn University, in the Department of Ophthalmology and New York City have tested a new procedure that replaces damaged RPE cells.
In the present experiment, RPE cells made from human stem cells were successfully implanted into the retinas of rabbits.
Boris V. Stanzel, the lead author of this work, said, “These cells have now been used for the first time in research for transplantation purposes.”
The adult RPE stem cells were characterized by Timothy Blenkinsop and his colleagues at the Neural Stem Cell Institute in New York City. Blenkinsop designed methods to isolate and grow these cells. He also flew to Germany to assist Dr. Stanzel with the transplantation experiments. Blenkinsop obtained his RPE cells from human cadavers, and he grew them on polyester matrices.
These experiments demonstrate that RPE cells obtained from adult stem cells can replace cells destroyed by AMD. This newly developed transplantation method makes it possible to test which stem cells lines are most suitable for transplantation into the eye.