LONDON, March 23 (Xinhua) -- Scientists have helped two patients regain vision from age-related macular degeneration (AMD) with a clinical trial of a stem cell therapy, offering a glimmer of hope for the treatment of a common cause of blindness.

The two patients, a woman in her 60s and a man in his 80s, each had one eye implanted with a patch of stem cells. The number of letters each of them could read correctly off an eye chart increased dramatically after the procedure.

The breakthrough, published earlier this week in Nature Biotechnology, was made by the London Project to Cure Blindness, a collaboration between University of College London and Moorfields Eye Hospital.

"In the months before the operation my sight was really poor and I couldn't see anything out of my right eye," 86-year-old Douglas Waters was quoted by the Guardian as saying. "After the surgery my eyesight improved to the point where I can now read the newspaper and help my wife out with the gardening."

There are two forms of macular degeneration, "wet" and "dry," with similar problems. In the advanced condition of AMD, retinal pigment epithelium cells in people's retinas die off, leading to macular degeneration and vision loss.

The team planned to treat 10 people who had the "wet" form of AMD, caused by sudden blood vessels leakage in the eye.

"While this is only a very early clinical trial, the results are positive and show that the technology is moving along in the right direction," Carmel Toomes, associate professor at the Leeds Institute of Molecular Medicine, was quoted by the Guardian as saying.

Scientists believe the procedure could be a common surgery in the near future. It's not clear how much it would cost.