Cure For Blindness? Optic Nerves Regenerated

Main Category: Eye Health / Blindness
Article Date: 29 Feb 2004 - 0:00 PDT

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Scientists are getting closer towards being able to repair damaged optic nerves.

According to scientists at the Harvard Medical School, they have been able to regenerate the optic nerves of rats.

They were not able to give the rats their sight back. However, regeneration of the optic nerve was three times greater than any other attempts ever made?

You can read about their research in the Journal of Neuroscience.

If these scientists can find a way to effectively re-grow the optic nerve, and other nerves, they could be well on the way to curing blindness and paralysis.

Nerve cells cannot regenerate (repair themselves). This means that any damage you have to one of your nerves is permanent (most likely).

The aim of scientists worldwide is to find a way of getting nerves to repair themselves, to re-grow.

The outer layer of nerve fibres have a protein on them that stops regeneration from happening.

Some scientists have found ways to stop these proteins, turning them off. However, there is more to it than that. Just doing this does not mean the nerves start to re-grow.

Dr Larry Benowitz and colleagues tried another approach, a double approach.

They got a group of rats with optic nerve damage. They then damaged the lens in the eyes of those rats. The optic nerve links the retina to the brain and makes it possible for you to see.

When they damaged the lens it stimulated an immune response. This means that cells travelled to the rats' eyes, released growth factors to repair the damage. While this was happening nerve fibres grew into the optic nerve.

They then used gene therapy to enhance what was happening. They injected a gene that stops that protein that blocks re-growth. The gene turns that protein off.

Dr Benowitz said 'When we combined these two therapies - activating the growth programme in nerve cells and overcoming the inhibitory signalling - we got very dramatic regeneration."

Unfortunately, they could not get the nerve fibres from the retina to hook up to the nerves from the brain properly (so rats were still blind).

Dr. Benowitz said it is a mapping problem. We have to retain the proper organisation of fibre projections to the brain. He believes further studies will overcome this problem.