The optic nerve connects the eye to the brain – a bit like a cable that connects a camera to a computer. It plays an essential role in our vision, allowing the brain to receive electrical signals from the back of the eye, so it can interpret them as images.

Glaucoma, the world’s second leading cause of blindness, affecting 60 million people globally, interrupts this transfer of visual information.

“As glaucoma develops, the optic nerve gets progressively damaged, and that causes gradual loss of peripheral vision,” says Professor Keith Martin, CERA’s Managing Director. “If left untreated, it can lead to total blindness.”

Currently, glaucoma treatment is largely aimed at protecting the optic nerve and preventing further damage, slowing the deterioration of vision.

A ground-breaking new project, led by Professor Martin with Professor James Fawcett from the University of Cambridge, is taking a different approach – trying to repair the optic nerve to restore lost sight.

The study, funded by UK charity Fight for Sight, will investigate the role of a ‘scaffolding molecule’ called protrudin in helping to regenerate nerve fibres to reconnect the retina to the brain.

“Essentially what we’re trying to do is improve the ability of the optic nerve to regenerate after injury,” Professor Martin explains.

“If you injure your skin, you might have a patch of numbness, but after a while the sensation improves. That’s because the nerves in the peripheral parts of your body can regenerate.

“The optic nerve doesn’t, and we’re trying to work out why.”

Strengthening nerve transportation systems

To do this, the team is striving to improve the ‘transport system’ within the nerve fibres of the eye. They’ve discovered that the molecule protrudin may hold the answer.

“We’ve found that if we increase the amount of protrudin or change the way it’s working, we can improve transportation along the nerve fibres,” says Professor Martin.

“And getting the right molecules to the right place at the right time can improve the ability of that nerve to repair.

“We are still at a relatively early stage, looking at the fundamental mechanisms of how protrudin is working. But what we’ve seen is the strongest regeneration of any technique we’ve used before.”

This research also has the potential to improve the success of eye transplants, helping a transplanted eye connect to the brain by growing axons through the optic nerve.

Hope for the future

Glaucoma can currently be managed with treatments including eye drop medication, laser and surgery, and early treatment can prevent vision loss in most cases. However, 10-15% of patients with glaucoma will go blind in at least one eye during their lifetime.

Restoring vision may be a long way off – but these early days are showing it is a realistic possibility for the future.

“In the past it seemed impossible that we’d be able to regenerate the optic nerve. We can potentially do this now, but it remains to be seen how much vision can be restored,” says Professor Martin.

“There is still much work to do and we will continue to work hard on this with the help of our supporters.”