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Scientists in UK Plan Stem Cell
Cure for Blindness
By Raza
Mumtaz 'Pakistan Times' Executive Editor/UK Bureau Chief
LONDON (UK): British
scientists plan to
use
stem cells to cure a common form of blindness, with the first patients
receiving test treatment in five years.
The pioneering project, launched on Tuesday, aims to repair damaged retinas
with cells derived from human embryonic stem cells. Its backers say it
involves simple surgery that could one day become as routine as cataract
operations.
They believe the technique is capable of restoring vision in the vast
majority of patients with age-related macular degeneration (AMD), a leading
cause of blindness among the elderly that afflicts around 14 million people
in Europe.
Some drugs, like Genentech Inc.'s Lucentis, can help the one in 10 patients
with so-called "wet" AMD and U.S. biotech firm Advanced Cell Technology is
looking at stem cells in other eye conditions. But there is no treatment for
the 90 percent with "dry" AMD.
AMD is caused by faulty retinal pigment epithelial (RPE) cells, which form a
supporting carpet under the light-sensitive rods and cones in the retina.
The new procedure will generate replacement RPE cells from stem cells in the
lab, with surgeons then injecting a small patch of new cells, measuring 4 by
6 millimeters, back into the eye.
The London Project to Cure AMD brings together scientists from University
College London (UCL), Moorfields Eye Hospital in London and the University
of Sheffield.
It has been made possible by a 4 million pounds ($8 million) donation from
an anonymous U.S. donor, who the project's leaders said had become
frustrated by U.S. curbs on stem cell work.
Embryonic stem cells are the ultimate master cells of the body, giving rise
to all of the tissues and organs. Their use is controversial because many
people oppose embryo destruction, although Britain has encouraged such
research.
Surgeons at Moorfields have already restored the vision of a few patients
using cells harvested from their own eyes, which were moved to a new site.
But this process is complicated and only a small number of cells can be
moved, limiting its use.
By injecting RPE cells derived from stem cells instead, Dr Lyndon Da Cruz of
Moorfields hopes the operation can be reduced to a simple 45-minute
procedure under local anesthetic.
"If it hasn't become routine in about 10 years it would mean we haven't
succeeded," he told reporters. "It has to be something that's available to
large numbers of people."
Similar tests on rats have already proved highly effective.
Pete Coffey of UCL, the director of the project, said he was confident the
procedure would work in humans but the team needed to ensure the safety and
quality of batches of cells, which would take time.
"The goal is within five years to have a cohort of 10 or 12 patients to put
the cells into," he said.
The project, which is non-commercial, was welcomed by patient support
groups. Alistair Fielder of the eye research charity Fight for Sight said it
represented a real chance to tackle a hitherto untreatable condition.●
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