By Saundra Young, CNN NEWS, October 17, 2014.
Researchers say that human embryonic stem cells have restored the sight of several nearly blind patients – and that their latest study shows the cells are safe to use long-term. According to a report published this week in The Lancet, the researchers transplanted stem cells into 18 patients with severe vision loss as a result of two types of macular degeneration, an eye disease that causes progressive loss of sight.
Nine had Stargardt macular degeneration, the leading cause of juvenile blindness, and nine had dry atrophic age-related macular degeneration, the most common cause of vision loss in people over 50. There are currently no approved treatments for either condition.
The Mayo Clinic defines macular degeneration as occurring when tissue in your macula, a spot in the center of your retina, thins and breaks down. Stem cells can help rebuild this tissue.
The study’s patients were followed for up to three years. Researchers saw no signs of rejection of the cells and no abnormal growth, tumor formation or unwanted tissue types in any of the patients during that time period. On average, the vision of the patients improved about three lines on the standard eye chart.
Patients in a control group who did not receive a stem cell transplant did not show similar sight improvement.