Researchers at the University of Canterbury, New Zealand are pioneering the development of an eye drop to halt the development of cataracts.
Cataracts are the major cause of blindness worldwide. Until now, the only option has been corrective surgery.
However, researchers from the University's Chemistry Department are trying to identify a compound which would act as an inhibitor and prevent cataracts from developing.
Cataracts cause the lens of the eye to become cloudy and prevent the passage of light.
Scientists believe that an increase in activity of the protein-destroying calpain enzyme causes the breakdown of the major lens proteins, the crystallins, leading to opaque lenses.
The Canterbury team, led by Professor Andrew Abell and Professor Jim Coxon, believe the inhibition of calpain activity could halt cataract formation.
"It is our goal to develop a compound to treat cataracts that can be incorporated into an eye drop and prescribed to treat cataracts," Professor Abell says.
The UC researchers have been working closely with colleagues at Lincoln University who have developed an animal model to allow a study of the progression of cataracts.
The Lincoln study has focused on a flock of sheep genetically predisposed to cataracts.
A calpain inhibitor has been tested on the animals. It was applied as eye drops and slowed, but did not prevent, the development of cataracts.
"These results are promising as they support our hypothesis that calpain activity is important in the development of the cataract and showed that inhibitors could interfere with cataract progression," Professor Abell says.
"Long waiting lists exist for cataract surgery in most affluent countries and one of our goals is to improve the quality of life of those that currently face blindness while awaiting a cataract operation. This is of even greater importance to third world countries."
The Canterbury team is working with Douglas Pharmaceuticals (NZ) to develop more efficient eye delivery systems and has links with Senju, a Japanese pharmaceutical company which specialises in eye care products.