Stem cells reverse blindness from chemical burns: study

The researchers have tested the method on more than 100 of patients who were blinded through either burns or who suffered eye damage when they were splashed with caustic chemicals.

Researchers from the Center for Regenerative Medicine Stefano Ferrari in Modena, Italy, harvested stem cells from the patients' healthy eyes, extracting cells from the thin ring around the iris, called the limbus.

They then grew the cells in a lab to make clear corneas and grafted the corneas onto the patients' damaged eyes.

The treatment was successful in nearly 77 per cent of the 112 volunteers, allowing them to see well again within a few months. An additional 13 per cent were considered a partial success.

Currently, for patients with damaged corneas, the only therapy is a corneal transplant. But that method usually provides only temporary relief.

That's because in some burn patients, after the limbus is destroyed, the cornea tries to repair itself instead using cells that cover the white of the eyeball, leading to a clouding over of the eye and blindness.

With a corneal transplant, the cells that caused clouding eventually take over in the absence of limbus cells.

But this new technique appears to restore sight for much longer —10 years or longer.

One man used in the study, had his eyes were severely damaged more than 60 years ago and now has near-normal vision.

What's more, because the new technique uses a patient's own stem cells, there is no need for anti-rejection drugs as there is in corneal transplants.

While the new technique is exciting, it works only on patients whose eye damage is confined to their corneas. Those with optic nerve damage or macular degeneration, which involves the retina, would not benefit.

Nor would it work in people whose eyes are completely, because doctors need at least some healthy limbus tissue that they can transplant.

The research appears this week in the New England Journal of Medicine.