Synthesising Sight

Corneal blindness is the fourth most common cause of blindness worldwide, causing 5.1% of all blindness. It is caused by damage and scarring to the cornea, the transparent covering of the eye which protects the pupil and iris and so the only real treatment for this kind of blindness has been a transplant of the cornea. This sounds simple enough, but donors are sparse and the procedure is risky and expensive, making treatment implausible in many developing countries.

For years, this has been the general prognosis for corneal blindness: either to live with it or patiently await a donor and even a transplant is only a temporary fix. However this week Sylvia Paton in Edinburgh became the first person to receive a stem cell transplant in the cornea to reverse the damage causing the disease.

Stem cells are the poster child of the tomorrow’s medicine and are at the core of the dynamic field of regenerative medicine. A stem cell is one which can generate a complete tissue of any kind in the body, herein lies their usefulness. A very small sample of stem cells could in the future be used to generate an entirely new lung or kidney or any other organ imaginable.

This procedure involved formation of new corneal tissue formed from stem cells which was replaced the damaged scarred tissue which caused the blindness.

It will be months before a the effect (if any) of this treatment may be seen but Professor Baljean Dhillon, a consultant ophthalmic surgeon at Murrayfield Hosptial in Edinburgh and the study’s principle investigator, is hopeful and says that such treatment “could bring sight to many people around the world who currently live in darkness”.

As pioneering as this treatment is, it is not the first of its kind. In July of last year, the first ever synthetic organ transplant was performed in Sweden, where a synthetic trachea coated in the patient’s own stem cells was transplanted in to a woman who had lost hers to cancer, while a surgeon in the USA has been performing transplants of synthetic bladders made from stem cells since the late ‘90s.

Professor Dhillon’s procedure potentially gives thousands of people around the world their sight back, however for patients with a genetic predisposition to corneal blindness – as this patient was – the stem cells must be obtained from the eyes of another adult donor. This does not really solve much for patients in this predicament since donations of eye tissue appears to be a source of distaste among the public and donors are of eye tissue are rare.