Monday, May 25, 2009

Stem-cell treatment of age-related macular degeneration being developed

From The Telegraph in the UK:

The world's first stem cell treatment for the most common cause of blindness has been developed by British scientists.

Surgeons believe a one-hour procedure to tackle age-related macular degeneration (AMD) could now be available within seven years.

Up to half a million Britons and 30 million others around the world are affected by AMD, in which the part of the retina responsible for central vision gradually thins, leaving one in 10 sufferers totally blind.

One in four over-60s in the UK suffers from the condition, which is predicted to worsen with Britain's ageing population.

The new treatment, pioneered by experts at the Institute of Ophthalmology at University College London and Moorfields eye hospital, involves replacing a layer of degenerated cells with new ones created from embryonic stem cells.

It is thought the therapy could help those both the 'dry' form of the condition, which is currently untreatable, and the 'wet' form which can be mitigated with injections.

The RNIB welcomed the announcement, which a spokesman said would "give hope to tens of thousands across the UK" with the dry form of the condition.

Tom Bremridge, chief executive of the Macular Disease Society, said: "This is a huge step forward for patients. We are extremely pleased that the big guns have become involved, because, once this treatment is validated, it will be made available to a huge volume of patients."

Pharmaceutical research firm Pfizer is expected to announce financial backing for the therapy this week.

Under the treatment, embryonic stem cells are transformed into replicas of the cells in the thinning part of the retina and inserted in the affected area.

The use of embryonic stem cells is controversial because it involves the destruction of human embryos.

The research team is seeking permission for clinical trials from the Medicines and Health care products Regulatory Agency, the Human Tissue Authority and the gene therapy advisory committee. If given the go-ahead, the trials would be the second in the world to use embryonic stem cells on humans. The first, on patients with spinal cord injuries, will start this year in the United States.

Professor Peng Khaw, director of the Biomedical Research Centre at Moorfields and the UCL Institute of Ophthalmology, added: "This shows that stem cell therapy is coming of age. It offers great hope for many sufferers around the world who cannot be treated with conventional treatment." He added: "All my patients say to me is, 'When will this stem cell treatment be ready? I want it now'."

Therapy already available for the treatable 'wet' form of AMD includes a series of injections that can halt the degeneration of the affected cells ain the retina, which lies at the back of the eye.

Some patients with AMD are able to adapt by using their peripheral vision. Among them was the late American painter Georgia O'Keefe who contracted the disease in the 1970s and whose later work sometimes featured black disc-like masses in the centre of the canvas.

Risk factors in the development of the condition include genetics, farsightedness and a diet low in vitamins, minerals and antioxidants.

More than one third of a million Britons are registered blind or partially sighted and, overall, the RNIB estimates two million have significant sight loss.