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Last Updated: Tuesday, 5 June 2007, 11:45 GMT 12:45 UK
Stem cell therapy for eye disease
Eye

UK scientists are attempting to restore vision in people with a leading cause of blindness using stem cells.

The team has already repaired the vision of a handful of patients with age-related macular degeneration using cells from the patients' own eyes.

With the help of a 4m donation, they are now planning to carry out the same operation using retinal cells grown from stem cells in the lab.

It is hoped the first patients would be treated within five years.

Age-related macular degeneration (AMD) affects around 25% of over-60s in the UK to some degree and causes blindness in 14 million people across Europe.

There are two types - dry - which makes up 90% of cases, and wet, which makes up the other 10%.

It is caused by the failure of retinal pigment epithelial cells (RPE) - a layer of support cells under the retina, which processes light.

This leads to the degeneration of the macula - the central area of the retina - and gradually knocks out central vision.

Using stem cells - which are far more adaptable - can only improve success of what has already been achieved and in addition establish this as a global therapy
Professor Pete Coffey

There are treatments for wet AMD but not for dry AMD.

Mr Lyndon Da Cruz, consultant ophthalmic surgeon at Moorfields Eye Hospital in London has carried out an operation in a handful of patients to take cells from the healthy periphery of the eye in patients with wet AMD and transplant them into the affected area.

The procedures have been successful but are associated with complications, take more than two hours and require two operations.

To make the procedure quicker, easier and more widely available, researchers at the University of Sheffield have grown RPE cells from embryonic stem cell lines.

The hope is that this can be processed into a layer that can be injected into the patient's eye during a simple 45-minute operation.

Tests of the laboratory grown RPE cells in rats with AMD showed they restored vision.

Collaboration

A 4m donation from a US benefactor who wishes to be remain anonymous has enabled the teams to set up the London Project to Cure AMD with the UCL Institute of Ophthalmology.

Professor Pete Coffey, director of the Project explained although they had successfully grown RPE cells in the laboratory, they now needed to make sure the cells were safe enough to be used in humans, which would take time.

STEM CELL TECHNOLOGY

Sources of stem cells

Key sources for stem cells are adult organs or embryonic cells

Adult stem cells

Adult stem cells are identified and separated from other cells

Embryonic stem cells

Embryonic stem cells are removed from 5-day-old embryos

Manipulation to form specialised cells

Cells are manipulated to stimulate them to take on a specific function

Uses for stem cells

Specialised cells may then be used to treat unhealthy areas

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"Using stem cells - which are far more adaptable - can only improve success of what has already been achieved and in addition establish this as a global therapy."

"The goal is within five years to have a cohort of patients to put the cells into," added Professor Coffey whose team is preparing the laboratory-derived cells for transplant

Mr Cruz added that if in 10 years the four by six mm transplant was not in global use something major would have failed in the research.

"We have the RPE, we have the evidence that doing this type of thing can restore vision. It's practicality issues rather than a big unknown."

More operations are also planned with the patients' own cells in those suffering from dry AMD to test the procedures effectiveness.

Professor Alistair Fielder, senior medical adviser for the eye research charity Fight for Sight, said: "The London Project represents a real chance to tackle this untreatable condition and bring hope to many."




SEE ALSO
Age-related macular degeneration
13 Jun 02 |  Medical notes

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