Three years ago Elisabeth Bryant believed she would be blind for the rest of her life. "I couldn't see anything," she says. Now, although her vision is not perfect, she can see well enough to read, play computer games and check emails.
Bryant has retinitis pigmentosa, an eye disease that has blinded four generations of her family. What has saved the sight in one of her eyes is a transplant of a sheet of retinal cells. The vision in this eye has improved from 20:800 to 20:84 in the two-and-a-half years since the transplant- a remarkable transformation. So far, six patients with either advanced retinitis pigmentosa or macular degeneration have had similar transplants.
Together, these degenerative diseases are the biggest cause of blindness in rich countries, affecting tens of millions of people. While Bryant's improvement is the most dramatic, four other patients have also had good results. When New Scientist reported the initial results of these retinal transplants last year (1 February 2003, p 14), experts cautioned that the results could be due to the rescue effect: a short-term improvement triggered by the release of growth factors after eye surgery. That appears increasingly unlikely, because the rescue effect usually lasts only months. "We have shown the way," says Robert Aramant at the University of Louisville in Kentucky, who developed the transplant technique with his colleague Magdalene Seiler. "It is possible to reverse these incurable diseases." No other technique has come close to achieving this. The team has received approval from the US Food and Drug Administration to carry out further transplants on people with less advanced disease, and Aramant believes the results will be even better.