Drugs cut glaucoma surgery risk

Scientists have developed drugs to prevent scarring in the eye, and possible blindness, following sugery to correct the condition glaucoma.

London-based researchers used different drugs to target more than one aspect of the scarring process at the same time.

Glaucoma is the most important cause of irreversible blindness worldwide, affecting more than 500,000 people in the UK alone.

The research is published in Nature Biotechnology.

Glaucoma is caused by increased fluid pressure within the eye compressing the nerves at the back of the eye.

This pressure then causes irreversible damage to the optic nerve at the back of the eye.

People undergo surgery if the management of their glaucoma is not sufficiently effective in lowering their eye pressure.

Glaucoma surgery is one of the few operations in which the aim is for the wound not to heal after surgery.

In the most common operation, trabeculectomy, the surgeon creates a flap over a small hole in the outer wall of the eye, to form a new passage for the fluid in the eye to drain away and thereby reduce the pressure within the eye.

However, the channel can become blocked because of scarring and this leads to the failure of the operation and blindness.

The new approach make use of tiny, tree-like molecules called dendrimers.

The researchers used two types, one to modify the immune response, and the second to suppress blood vessel growth after injury.

In combination, they signficantly reduced scar formation and improved healing after surgery.

Lead researcher Professor Sunil Shaunak said: "Our approach is a departure from traditional drug design and we have been astonished by the dramatic results.

"The increase in the success rate of glaucoma surgery from 30% to 80% in animals treated with this drug has encouraged us to start planning clinical trials in humans."

David Wright, of the International Glaucoma Association, said the people who were most at risk of scarring tended to be relatively young.

He said the association would await the results of human trials with great interest.

The research was a joint project between Imperial College London, the Institute of Ophthalmology at University College London, Moorfields Eye Hospital, and The School of Pharmacy, University of London.

They hope the technique could be used to damp down the immune response following burns, and some forms of blood poisoning.

Source: BBC News