ANAHEIM, Calif., March 22 -- New materials that may extend the wear of contact lenses and lessen the risk of eye infection were described by researchers from the University of California, Berkeley, today at the national meeting of the American Chemical Society, the world's largest scientific society.
The material, called a sulfoxide hydrogel polymer, enhances the water level in the eye while minimizing undesirable protein buildup. Scientists claim it will enable contact lenses to be worn for longer periods of time, prevent bacterial buildup in the eye, and increase comfort. "The excess water in the lens makes it softer and, therefore, more comfortable to the wearer, besides providing much required oxygen to the eye," says Dr. Ravi Mukkamala, who presented the findings.
Dr. Mukkamala, who currently works as a senior scientist at Rohm and Haas Texas Inc. in Houston, was the co-inventor of the materials, along with Prof. Carolyn Betozzi in the chemistry dept. of UC Berkeley. What makes the materials unique, they say, is the addition of sulfoxide groups to the hydrogel polymer.
Currently, soft contact lenses made from hydrogels are capable of holding water, but not without greatly affecting the protein deposition. In conventional lenses, any chemical modification made to the lens material to increase the water level -- an important component in supplying oxygen to the eye -- adversely increases the protein deposition on the lens surface. This increase in protein could lead to such problems as infections and blurred vision.
"The sulfoxide hydrogels, on the other hand, possess characteristics that set them apart from the rest of the hydrogel systems," says Mukkamala, and may offer fresh possibilities for the design of new materials where wettability and bulk hydrophilicity are important factors.
The sulfoxide hydrogel lenses, currently undergoing clinical trials, could be available as early as next year.
A nonprofit organization with a membership of nearly 159,000 chemists and chemical engineers, the American Chemical Society publishes scientific journals and databases, convenes major research conferences, and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.