Thursday, April 7, 2011

Scientists grow retina from stem cells in lab bringing vision restoring transplants closer

From The Daily Mail in the UK: In the picture, two optic cups can be seen, which form as the stem cells grow into an embryonic eye

Part of an eyeball has been grown in a lab, paving the way for ‘DIY transplants’ that would offer hope to millions of blind people.

The retina – a light-sensitive ‘film’ crucial to vision – was produced from scratch in what experts describe as an ‘astounding’ achievement.

Sufferers of age-related macular degeneration – the most common cause of blindness in the elderly – are among those who could benefit within years.

The Japanese researchers used ‘blank’ embryonic stem cells, which can turn into any cell in the body, as their starting material.

They then added a cocktail of proteins and chemicals to coax the cells into developing into parts of an eye.

Although the resulting retina did not mature, it was roughly at the stage found in a baby before it is born, reported the journal Nature.

The experiments, from the RIKEN Centre for Developmental Biology in Kobe, were carried out in mice. Scientists have yet to show that the cells actually work.

Despite this, British eye expert Robin Ali, a professor at University College London, said: ‘It is a really, really major landmark. To see that beautiful structure in a dish as if it had just been taken from an animal is absolutely astounding.’

He believes tests on people could take place in as little as five years.

In just ten to 20 years, synthetic retina cells could be used to restore sight to the blind, he added.

The retina, which lines the back of the eye, picks up light and sends it through the optic nerve to the brain for conversion into images. In age-related macular degeneration, which affects more than 600,000 Britons, the deterioration of its light-sensitive cells – or photoreceptors – creates a blackspot in the vision.

This can make it impossible to carry out everyday tasks such as reading, driving and watching television.

In future, it might be possible to begin with nothing more than a sliver of skin from a patient’s arm.

These cells would be developed into a retina that would perfectly match the person. Its light-sensitive cells could be injected into the back of the eye to repair damage and restore vision.

Oxford University eye surgeon Robert MacLaren said: ‘The thought that we may be able to generate the cells in large numbers from patients’ own skin is very exciting.’

Dr Dolores Conroy, of the Fight for Sight charity, said the research ‘could have important implications’ for sufferers of age-related macular degeneration.