Stem cells: Cure for macular degeneration?

WORCESTER, Mass., Sept. 21 (UPI) -- U.S. scientists say embryonic stem cells can slow vision loss when injected into rats suffering from a disease similar to macular degeneration.

The finding supports the idea of trying the technique in humans suffering from macular degeneration -- the leading cause of blindness in people older than 55, The Washington Post reported.

Raymond Lund, then at the University of Utah, and Dr. Robert Lanza of Advanced Cell Technology Inc. in Worcester, Mass., started by developing a method of turning embryonic stem cells into retinal pigment epithelium cells, which nourish the eye's light-sensitive "photoreceptor" cells, the newspaper said. In macular degeneration, the pigment cells gradually disappear.

The researchers said they succeeded in all 18 stem cell lines they worked with, injecting the stem cells, about 20,000 per eye, into the retinas of 14 rats with a genetic disease similar to macular degeneration. Eight control rats received eye injections without any cells.

The scientists found treated rats were twice as responsive as untreated ones, which started to become blind. The study also showed treated rats had twice the visual acuity of untreated rats nearly three months after treatment.

The research is detailed in the journal Cloning and Stem Cells.