02/27/2012
Stem cells offer first glimpse of blindness treatment.
By Dan Vergano, USA TODAY
In the first published results of a therapy using human embryonic stem cells, the controversial treatment slightly improved the vision of two legally blind patients, researchers reported Monday. Intended as a safety test, the experiment reported in the journal The Lancet follows more than a decade of debate over human embryonic stem cells. Seen as a potential treatment of diseases such as diabetes and blindness, the therapy has also drawn criticism from conservative groups that have decried the cells' origins — removed from early human embryos that are destroyed in the process, and then grown into colonies for research.
"We're showing these cells indeed seem to be safe and help patients," says study senior author Robert Lanza of Advanced Cell Technology in Marlborough, Mass., which funded the study. University of California, Los Angeles, surgeons on the study team last year injected 50,000 cells each into one eye of two women suffering untreatable forms of macular degeneration, a progressive blindness that afflicts more than 8 million people nationwide.
Four months after the injections, neither study patient had lost vision, as usually happens in progressive blindness, or showed signs of abnormal growth in their eyes, quelling fears associated with the cells that they could give rise to tumors. One patient with Stargardt's macular dystrophy, a common form of blindness in kids, saw demonstrably improved vision, while the other patient's improvement looked more ambiguous. She also seemed to be seeing better in her uninjected eye.
The study noted that surgeries sometimes produce false "placebo" benefits for patients. However, the study shows new retinal cells growing in patches ravaged by blindness in the patient's eyes.
"Ten years ago we told these patients they were going to go blind. These results show a lot of promise to change the landscape," says retinal surgeon Rama Jager of University Retina in Oak Forest, Ill., who was not part of the study. Growth of new cells in the patients' eyes seen in the study is "really spectacular," Jager says. "You just don't see that in these patients."
However, biologist David Prentice of the Family Research Council in Washington D.C., a past critic of embryonic stem cell research, called the results, "way too early, and way too few patients to call this safe."
