Stem cells transplanted into the eyes of mice with retinal disease restored and improved the animals’ vision, a finding that may yield benefits for patients with eye disease, researchers report.

Dr. Michael J. Young, from Harvard Medical School in Boston and colleagues harvested retinal stem cells from newborn mice that had been bred with a gene that colored their tissues fluorescent green. The cells were then transplanted into the degenerating retinas of adult mice.

After transplantation, the stem cells became nerve cells that are needed for vision, according to the report in Investigative Ophthalmology and Visual Science. Furthermore, the mice that received the transplants showed improved responses to light.

A press release from the Schepens Eye Research Institute at Harvard Medical School points out that “many of the (eye) cells that were on the verge of dying before the transplant appeared to regain or retain their function.”

The researchers speculate that the transplanted cells may work, in part, by secreting chemicals that help save these dying cells.

“These are the first steps toward the use of stem cells for saving existing vision and then - down the road - restoring vision that has already been lost,” Young comments in the press release. His team is now extending the research into larger animal models.

SOURCE: Investigative Ophthalmology and Visual Science, November 2004.