June 2, 2009 The humble contact lens has long been used to improve people’s vision, but now researchers have restored sight in patients suffering corneal damage using a groundbreaking technique where contact lenses are cultured with stem cells.
The idea stemmed from the observation that stem cells from the cornea (the thin, transparent barrier at the front of the eye) stick to contact lenses. Employing three patients who were blind in one eye, the researchers obtained stem cells from their healthy eyes and cultured them in extended wear contact lenses for ten days. The surfaces of the patients’ corneas were cleaned and the contact lenses inserted. Within 10 to 14 days the stem cells began to recolonize and repair the cornea.
“The procedure is totally simple and cheap,” said lead author of the study, UNSW’s Dr Nick Di Girolamo. “Unlike other techniques, it requires no foreign human or animal products, only the patient’s own serum, and is completely non-invasive.
Of the three patients, two were legally blind but can now read the big letters on an eye chart, while the third, who could previously read the top few rows of the chart, is now able to pass the vision test for a driver’s license. The research team isn’t getting over excited, still remaining unsure as to whether the correction will remain stable, but the fact that the three test patients have been enjoying restored sight for the last 18 months is definitely encouraging. The simplicity and low cost of the technique also means that it could be carried out in poorer countries.
The procedure also works in patients who have had both eyes damaged. “One of our patients had aniridia, a congenital condition affecting both eyes," said Dr Di Girolamo. "In that case, instead of taking the stem cells from the other cornea, we took them from another part of the eye altogether – the conjunctiva – which also harbors stem cells."
Diseases affecting the cornea are one of the main causes of blindness around the world. The World Health Organization estimates that corneal disease could be responsible for 1.5 million people losing sight in one of their eyes every year.
Although at the moment the treatment can only help people with damage to the edge of the cornea, the researchers say that in the future the technique could be used to help people blinded by other causes. As well other parts of the eye such as the retina, major organs such as the skin could also be regrown using the technique.
The research team has applied for funds to continue the project. Given their results to date, we’d like to see them get it.
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