LONDON • British surgeons have treated the first patient in a pioneering human embryonic stem cell operation which they hope will lead to a cure for blindness.
Specialists at London's Moorfields Eye Hospital said the operation on a woman aged 60 was successful and was the first of 10 planned for participants in a trial of the treatment for a disease called wet age-related macular degeneration (AMD).
The procedure involves seeding a tiny patch with specialised eye cells known as retinal pigment epithelium, derived from embryonic stem cells, and implanting it at the back of the retina, delivering the treatment cells to replace diseased cells.
Stem cells are the body's master cells, the source of all other cells. Scientists who support the use of embryonic stem cells say they could transform medicine, providing treatments for blindness, juvenile diabetes or severe injuries.
However, critics object to them because they are harvested from human embryos.
Moorfields hospital said in a statement yesterday that the operation was performed last month, and "there have been no complications to date". "The team hopes to determine her outcome in terms of initial visual recovery by early December," it said.
Professor Lyndon Da Cruz, the retinal surgeon who is performing the operations, said he hoped many patients "will benefit in the future from transplantation of these cells".
Macular degeneration accounts for almost 50 per cent of all cases of blindness or vision loss in the developed world. It usually affects people over age 50 and comes in two forms, wet and dry.
Wet AMD, which is less common than dry AMD, is generally caused by abnormal blood vessels that leak fluid or blood into a region in centre of the retina.
The trial is part of The London Project to Cure Blindness - a partnership between Moorfields, University College London's (UCL) Institute of Ophthalmology, and Britain's National Institute for Health Research. US pharmaceutical firm Pfizer joined the project in 2009.
UCL professor of regenerative medicine Chris Mason said the trial is important both as potential step towards curing a major cause of blindness and as a way of deepening understanding of the use of embryonic stem cells.
"If the AMD trials are successful, then by using embryonic stem cells as the starting material, the therapy can then be affordably manufactured at large scale," said Prof Mason.
In an earlier trial, 40 AMD patients at Moorfields were treated with cells taken from their own eyes, said the BBC.
"We saw extraordinary recovery, with some people being able to read again and drive, and that recovery being sustained for years," Prof Da Cruz told the BBC.