Blindness eased by historic stem cell treatment

For the first time since they were discovered 13 years ago, human embryonic stem cells (hESCs) have shown medical promise.

Two people with eye degeneration both say their vision improved in the four months after they received implants of retinal pigment epithelial cells made from hESCs. The treatments were also safe, with no sign that the cells triggered aggressive tumours called teratomas, no sign of immune rejection of the cells, and no inflammation.

Discovered in 1998, hESCs had previously failed to deliver on their medical promise. The new procedures, performed by Robert Lanza of Advanced Cell Technology of Marlborough, Massachusetts, and colleagues, could represent a turning point for hESC therapies.