More than 500,000 people in the UK have irreversible blindness caused by macular degeneration and it is estimated that one third of the population could be affected by 2070. The disease is marked by a progressive loss of central vision due to degeneration of the macula - a pigmented spot at the back of the retina.
Now the first successful animal trial to correct this disorder has been recorded by a London-led team given £4 million by an anonymous American philanthropist, who saw his father go blind, towards the cost of developing a stem cell therapy, where cells taken from a surplus human in vitro fertilization embryo are used to repair the eye.
Professor Pete Coffey (pictured) and Lyndon da Cruz, an eye surgeon, of the University College of London (UCL) Institute of Ophthalmology, have teamed up with Professor Peter Andrews, of the University of Sheffield, to take the treatment into hospitals. The recent tests with pigs mark a milestone.
"The results [with pigs] are really encouraging," says Professor Coffey. "We plan to do the first patient within 3 years."
Using surgical instruments introduced through three 1-millimeter holes in the eye, the team goes under the retina (a translucent layer) then inflates it so it separates from the underlying cells. The human eye cells derived from embryonic cells were then introduced on a rolled up patch and injected through a 1-millimeter hole, where the patch of human cells unfolded under the retina.
"I was over the moon when I got the results because it is a proof of concept," says Professor Coffey. "We really can do it."
Although the implanted human cells are black, the same as the surrounding pig cells, they can be distinguished when light of a given color is shone into the eye. The human cells glowed when viewed this way under the gaze of an instrument called a scanning laser opthalmoscope. "That indicates good function," says Coffey.
The operation on three sighted pigs took only 30 minutes, suggesting the stem cell implants could eventually become a routine outpatient operation, they told an event backed by the company Mostra at the Globe Theatre to promote the London Project to Cure Blindness - a scientific initiative between UCL, Moorfields, and The University of Sheffield.
Although it has already raised £4 million for the work, the team has failed to raise matching funding from the troubled UK Stem Cell Foundation to fully develop the treatment. "The main issue is to raise more funding," says Coffey. "If we do not get the money it will seriously slow down the project."
Illustration: University College of London.
University of College London In the News (01/16/08)
University College of London Institute of Opthalmology