Stem cells used in bid to cure 'silent thief of sight'

Scientists, using laboratory tests on animals, have successfully grafted stem cell tissues taken from bone marrow on to damaged nerves in the eye.

When the healthy cells are in place the eye begins to repair itself suggesting the technique could be used in the fight to cure blindness.

The project is funded by a 320,000 grant from charity Fight for Sight, which is supporting today's World Glaucoma Day.

Glaucoma is the most common cause of irreversible blindness in the developed world and is becoming increasingly prevalent as the population ages.

It is dubbed "the silent thief of sight" because of the insidious manner in which many patients have already suffered significant visual loss before they are diagnosed.

Blindness develops progressively in glaucoma as the neurons connecting the retina to the brain gradually die.

Around 80,000 people in Scotland live with glaucoma, with the prevalence rising from 1-2 per cent of the over-40s, to 5 per cent of the over-75s. Across the UK, more than 500,000 people suffer to varying degrees, and worldwide as many as 65 million people may be affected.

Currently, the only treatment which can slow progression of the disease is reducing eye pressure medically or surgically. However, for some patients deterioration continues even with this intervention until sight is lost entirely.

Professor Keith Martin, a neuroscientist at Cambridge University, said: "Glaucoma remains a leading cause of blindness worldwide and there is currently no way to restore vision once it has been lost. Fight for Sight funding is helping us explore the possibility that stem cell treatments could one day be used to treat glaucoma.

"Initially, we are looking at how stem cells can protect the eye against glaucoma damage when other treatment has failed.

"We have recently had some very encouraging results in animals with glaucoma which shows that stem cells can protect against glaucoma damage.

"In the future, our dream is to be able to use stem cell treatments to improve vision in patients severe glaucoma. However, it will be a few more years until these treatments are ready for human clinical trials."

The procedure used involves scientists extracting stem cells from blood and bone marrow before modifying them and attaching them to damaged eye cells.

The altered cells can then protect the blind patient from further glaucoma damage and even regenerate dying cells.

Dr Dolores Conroy, research officer for Fight for Sight, said: "Advances in stem cell technology are likely to revolutionise treatments for diseases like glaucoma."We must invest in this research field now so treatments to save, and potentially restore, the sight of millions of people are available in the future."

Recent evidence suggests neuron death in glaucoma shares some characteristics with other neurodegenerative conditions such as Alzheimer's and Parkinson's disease meaning understanding of glaucoma may have implications for other brain diseases and vice versa.

Glaucoma has been highlighted as a priority eye disease by the World Health Organisation.