People suffering from a rare genetic eye disorder which results in loss of vision are being given stem cell therapy by specialists in West Sussex.
Stem cells can be used to develop different kinds of tissue
A team at the Queen Victoria Hospital, in East Grinstead, said four patients had so far reported an improvement in their condition following treatment.
Stem cells from the patients, dead donors or living relatives are grown in a lab and transplanted onto the cornea.
Sufferers of the disorder, called aniridia, are born with no iris.
They have few or no limbal stem cells under the eyelid, which in turn disrupts the surface of the cornea resulting in pain and loss of vision.
Hospital eye specialist, Sheraz Daya, said transplanting stem cells somehow triggered the production of new limbal cells.
"We think the donor cells have attracted stem cells from the bone marrow to make new limbal stem cells, which have arrived at the eye through the bloodstream," he explained.
Four patients have experienced an improvement in their comfort and vision in one eye.
An international conference of eye specialists in New Orleans, America, later this year will hear the results of the aniridia trials.
Mr Daya and his team have also been using stem cell therapy over the past few years on patients who have suffered blindness for other reasons, for example because of injuries to their eyes.