How can scientists 'cure' blindness?

What have the scientists done?

The team from the London Project to Cure Blindness have created a tiny patch or carpet of cells which they have implanted into the eye of a woman who has sight loss caused by a condition called Age-related Macular Degeneration or AMD.

The cells they used to make the patch are called stem cells and came from a donated early embryo.

How does this work?

Stem cells are immature and can be coaxed to grow into any type of cell or tissue found in the body. The cells on the patch are destined to become retinal pigment epithelium - a cell layer lining the back of the eye which nourishes and supports other cells that let us see colours and images in our central field of vision.

In AMD, patients lose their central vision, which becomes distorted.

Replenishing the damaged retinal pigment epithelium should remedy this, scientists believe.

What does it entail?

The surgery takes a couple of hours to do.

The patch is rolled into a thin tube and then injected into the eye.

Once unfurled, it sits at the back of the eye and should, it is hoped, replenish the damaged cells that are causing the sight loss.

Is it a cure?

At this stage it is too early to tell.

So far one woman, a 60-year-old, has had the pioneering procedure done. Her doctors will not know until at least Christmas how well the treatment has improved her vision.

Ten other patients with AMD will undergo the same procedure and will be monitored for a year to check if the treatment is safe and works.

Animal trials have been promising but only time will tell whether this translates to humans.

Could it help with other sight problems?

The treatment is designed to help people with a leading cause of vision loss called AMD.

This condition, which affects more than 600,000 people in the UK, is more common with age and causes sufferers to lose central vision, usually in both eyes.

There are two main types of AMD - wet and dry. The patch has only been tested in patients with wet AMD so far, but the researchers hope it could help treat both types.

A similar stem cell injection helped patients with a rare type of vision loss called Stargardt's disease - an inherited condition that causes progressive loss of central vision.

But there are many other types and causes of blindness and stem cell treatments will not necessarily be able to help them all.

Can I get it on the NHS?

The treatment is still at the experimental stage and so is not available to patients other than those taking part in the trial.

The scientists hope it will become a mainstay of treatment for AMD, but that would still be some years from now.

And it's not clear how much it would cost.

But researchers say it should be affordable for the NHS and could even save the health service money. Currently, people with AMD need repeated treatment with expensive medicines to keep the condition at bay. There is no cure for AMD.

(BBC)