Toronto, Oct 9 (IANS): Researchers from the University of Waterloo in Canada have developed a topical solution containing nano-particles that will combat dry eye syndrome with only one application a week.

Currently, for those suffering from dry eye syndrome, the only recourse to ease the painful condition is to use drug-laced eye drops three times a day.

The new eye drop progressively delivers the right amount of drug-infused nano-particles to the surface of the eyeball over a period of five days before the body absorbs them.

One weekly dose replaces 15 or more to treat the pain and irritation of dry eyes.

The nano-particles, about 1/1000th the width of a human hair, stick harmlessly to the eye's surface and uses only five percent of the drug normally required.

"You cannot tell the difference between these nano-particle eye drops and water," said lead researcher Shengyan Liu from the faculty of engineering.

"I knew that if we focused on infusing biocompatible nano-particles with Cyclosporine A, the drug in the eye drops, and make them stick to the eyeball without irritation for longer periods of time, it would also save patients time and reduce the possibility of toxic exposure due to excessive use of eye drops," Liu explained.

The research team is now focusing on preparing the nano-particle eye drops for clinical trials.

The paper appeared in the journal Nano Research.