Curing cataracts with eye drops

A team of researchers has identified a chemical that could potentially be used in eye drops to reverse cataracts, the leading cause of blindness.

UC San Francisco (UCSF), the University of Michigan (U-M), and Washington University in St. Louis (WUSTL) researchers' newly identified compound is the first that is soluble enough to potentially form the basis of a practical eye-drop medication for cataracts.

Cataracts are primarily a disease of aging. As is seen in neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease, a hallmark of the condition is the misfolding and clumping together of crucial proteins. In the case of cataracts, the affected proteins are known as crystallins.

Crystallins are the major component of fiber cells, which form the eyes' lenses, and the unique properties of these cells make them particularly susceptible to damage, said co-senior author Jason Gestwicki.

The team next tested compound 29 in an eye-drop formulation in mice carrying mutations that make them predisposed to cataracts. In experiments conducted with Usha P. Andley, they found that the drops partially restored transparency to mouse lenses affected by cataracts, as measured by a slit-lamp test of the sort used by ophthalmologists to measure cataracts in humans.

Similar results were seen when compound 29 eye drops were applied in mice that naturally developed age-related cataracts and also when the compound was applied to human lens tissue affected by cataracts that had been removed during surgery.

Gestwicki cautions that slit-lamp measures of lens transparency used in the research are not a direct measure of visual acuity and that only clinical trials in humans can establish the value of compound 29 as a cataract treatment.

The study is reported in Science.