Potential remedy for most common cause of blindness

Patients affected by the most common cause of blindness in Ireland may enjoy a brighter future after an important discovery by scientists in Dublin.

They have identified a potential treatment to slow or halt vision loss that relies on a drug that has already been used safely in human trials.

"We probably have skipped over years of drug development. It is very exciting that the translation of this basic research will move very quickly now," said Matthew Campbell, professor of genetics at Trinity College Dublin.

It is a treatment for age related macular degeneration, a disease that makes blood vessels beneath the retina grow abnormally. This causes the loss of central vision, used for example for reading, driving or looking at a computer screen.

In 2012 Prof Campbell and colleagues discovered that a component of the immune system, known as Il-18, could protect sight by retarding growth of damaging blood vessels.

Coincidentally, he heard that drug company GlaxoSmithKline was running human trials on Il-18 for the treatment of cancer. “We asked could we use some of their Il-18 in our labs to test whether it was toxic for the eye. And we wanted to see if it could prevent onset of [vision loss]. He joined with lead author Prof Sarah Doyle, an assistant professor in immunology at Trinity, and other colleagues to test Il-18.

They published their findings yesterday in the journal Science Translational Medicine .

Potent treatment
There were early concerns it would harm the retina, said Prof Doyle

. “But surprisingly we found that low doses had no adverse effects on the retina and yet still suppressed abnormal blood vessel growth,” she said.

“We found it was very potent in preventing blood vessel development,” said Prof Campbell said. “The next goal is to show this can work in humans.”

It could replace the current best treatment which involves direct injections into the eyeball costing €1,000 per injection, he said.

The drug is being trialled and has not yet received approval. “It is still tiny steps,” said Prof Campbell. But if it is proven to work the treatment could reach the market relatively quickly.