British and American researchers announced in December that they had succeeded in using genetic engineering to restore sight to rats who went blind due to a condition that is the leading cause of sight loss in people over 50 in the Western world.
About 230,000 people are legally blind in the United States due to age-related macular degeneration, and many others have seriously impaired vision due to the disease. The disease is caused by the hardening of the arteries that bring blood to the retina. Deprived of some of the oxygen and nutrients the retina requires, vision in the center of the retina begins to deteriorate. The disease rarely leads to total blindness, but it can leave people with nothing but peripheral vision.
Researchers took genetically engineered human retinal pigment epithelial cells and transplanted them into rats who were born with a genetic predisposition to retinal degeneration. Not only did the cells survive — the first time this sort of cell has been successfully transplanted — but they restored the sight of the rats.
Professor John Greenwood of London’s Institute of Ophthalmology told the BBC,
The transplanting of genetically engineered RPE cells is totally unique. At present, there is no truly effective treatment or cure for age-related macular degeneration. We believe this work represents a tremendous leap forward in our endeavor towards developing a feasible strategy for treating patients with this debilitating disease.
Source:
Cell transplant reverses blindness. The BBC, December 17, 2001.