Stem cell scientists take hope from first human trials but see long road ahead

Marcus Hilton sits in front of the TV and stares at the Sky News headlines scrolling along the bottom of the screen. If he moves his head about he can find the little patch of vision in his right eye where letters jump from a tiny size to suddenly bigger. It is a small but crucial difference for Hilton, and it represents a huge scientific achievement.

Hilton has the distinction of being the first person in the UK to receive a transplant of human embryonic stem cells. He has Stargardt's disease, a condition that destroys the central vision of the eyes at an early age. His view of the world is limited to what the rest of us catch on the edge of our field of vision. He was diagnosed when he was about 10, after various pairs of glasses did no good at all. Now 34, he recalls: "I could never see the blackboard. I was blagging my way through school – native wit.".

Scientists hope that stem cells may restore the sight of people like Hilton and the many millions of older people suffering from macular degeneration, the most common cause of blindness. Hilton is part of the world's first trial using retinal pigment epithelium (RPE) made from stem cells derived originally from embryos left over from fertility treatment.

That makes the treatment controversial for some people, particularly in the US where Advanced Cell Technology (ACT), the company that has produced the RPE cells and is running the trial, is based. "I've had a few bizarre emails from crazy Americans," says Hilton. "And some crackers Americans saying great things as well – one from a share-buying group."

full: http://www.guardian.co.uk/science/2012/jun/04/stem-cell-first-human-trials