Age Related Macular Degeneration

News has been released that British scientists are planning to use embryonic stem cells to cure age related macular degeneration, a common form of blindness. They are hoping to have the first patients receive test treatments within five years. This could be a major improvement in the methods of treating this common form of eye blindness that is experienced by millions of individuals throughout the world.

The pioneering project uses cells derived from human embryonic stem cells to repair damaged retinas. Those who support the research believe the process will involve simple surgery that could one day become as routine as cataract operations. Scientists are suggesting that the technique might be capable of restoring vision in patients with age-related macular degeneration (ARMD), a leading cause of blindness among the elderly that afflicts millions of people worldwide and is the leading cause of blindness in the USA and Europe.

Newer drugs, like Genentech’s Lucentis, can help slow the progression of “wet” ARMD and can help restore some vision lost in the 10% of patients whose “dry” ARMD has worsened into “wet” ARMD (named for the bleeding that is occurring in the retina). US biotech firm Advanced Cell Technology is looking at stem cells in other eye conditions. Currently the only treatments for the 90 percent with “dry” AMD are methods of prevention. “Wet” ARMD is considered more severe and more potentially vision-threatening than “dry” ARMD.
Current methods of preventing progression of “dry” ARMD include vitamin therapy, smoking cessation, exercise, increased green vegetable consumption, and avoidance of ultraviolet light. ARMD is caused the failing of retinal pigment epithelial (RPE) cells to clear metabolic wastes from the retina. As waste products build in the retina they damage the inner lining of the retina and can lead to loss of photoreceptors or bleeding in the retina.

Embryonic stem cell research could generate replacement RPE cells from stem cells in the lab. Eye surgeons could then inject the new cells into the eye to replace the failing RPE cells. 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 $8 million donation from an anonymous US donor, who the project’s leaders said had become frustrated by US efforts to prevent 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.