The researchers expect to begin animal testing early next year. What they reported to the American Chemical Society was work that involved mechanical and physical testing of the hydrogel that was done in the laboratory. Before testing the hydrogel in animals, the researchers also hope to improve the material's refractive index -- the degree at which it refracts light -- a key to how well the eye can focus once the material is implanted.

"Currently, in this particular system, the refractive index has been a little low," Fetsch says. "It's not good enough to be able to provide much more than blurry vision."

But other researchers in Ravi's group, particularly research associates Hyder Ali Aliyar, Ph.D., and Paul Hamilton, Ph.D., have successfully formed several soft gels with the appropriate refractive index. "It's a very significant breakthrough," Ravi says.

The researchers admit there is still much work ahead before an injectable lens could be used in human patients, but Fetsch and Ravi expect it would be introduced into cataract patients first.

"Assuming we can demonstrate that the hydrogel is safe and effective in animal studies, we probably would first offer the technology to cataract patients," Ravi says. "By the time a person has cataracts, they almost certainly have presbyopia, too.

'"/>

Contact: Jim Dryden
drydenj@msnotes.wustl.edu
314-286-0110
Washington University School of Medicine
8-Sep-2003