Can sharks prevent blindness?

Eye drops made from a chemical found in the livers of sharks could help prevent blindness.

The new drops contain a compound called squalamine, which sharks produce to help stop infection.  A synthetic version of the compound is being trialled as a treatment for age-related macular degeneration (AMD).

AMD is the leading cause of blindness in Britain, affect more than 500,000 people.  Wet AMD occurs in 10% of cases and can lead to blindness due to the growth of unwanted blood vessels at the back of the eye.  These vessels tend to be fragile, which can lead to fluid leaks and causes scar tissue to form, destroying vision in the centre of the eye.

To manage the condition, patients can use daily eye drops and need to visit the hospital every 4-8 weeks for injections directly into the eye.  Currently, there is no way to reverse the effects, only slow them down.

The trial, at Indiana University, showed that the compound reduced the growth of the unwanted blood vessels by a third.  It works by blocking the effects of certain proteins that stimulate growth of these blood vessels.

Professor Bernie Chang, honorary secretary of the Royal College of Ophthalmologists, said, “This could be one of the most exciting developments in treating AMD.  If it works as well as current drugs, it would mean patients would not have to come to hospital for injections into their eyes. But we need to be sure it works and does not have major side-effects.”