Researchers have succeeded in growing light-sensing eye cells from human skin cells, opening the possibility of restoring sight to patients blinded by certain diseases.

Researchers at the University of Wisconsin have grown retinal cells from skin cells, a development that could be used to treat degenerative eye diseases.

A number of genetic disorders involve the degeneration of the retina, the light-sensitive cells at the back of the eye.  The disorders cause the cells to die, and vision is gradually lost, resulting in blindness.

The researchers manipulated human skin cells to act like embryonic stem cells, which can be coaxed to grow into any tissue in the body.  The development suggests that doctors may someday be able to repair damage to the retina with new cells generated from the patient's own skin.

Lead researcher David Gamm, a professor of ophthalmology and visual sciences at the University of Wisconsin, says his research could benefit people with macular degeneration and retinitis pigmentosa.  In both diseases, the visual field gradually narrows, eventually leading to blindness.

"In particular these diseases are quite devastating to the patients who are affected by them," he said.  "They rob them of their vision either when they are younger in the case of retinitis pigmentosa or when they are older in the case when they are older in the case of macular degeneration.  And there are no cures and very few if any treatments for them.  So it is a big need, especially from the macular degeneration standpoint, as the population ages."

An estimated one million people worldwide are affected by macular degeneration alone.

Gamm says the laboratory process of creating human retinal cells helps researchers better understand how eyes develop, so diseases that lead to vision loss may someday be treated or even cured with retinal stem cells.

The development could also further research on genetic eye conditions.  For example, using skin cells from a patient with retinitis pigmintosa researchers could create retinal cells with the defective gene and subject them to various potential drugs for treating or curing the condition.

Gamm says the same technique could help scientists find treatments for other genetic diseases, not just eye disorders. 

"Now we could take theoretically any human disease, especially those that have specific gene defects underlying them, and produce cell types of interest in those diseases and test them directly for the efficacy of various drugs or how in fact those cells die in disease," he added.

The study on the development of eye cells is published this week in the journal Proceedings of the National Academy of Sciences.