New cataract drug could eliminate need for surgery

Surgery for cataracts may become unnecessary in the wake of a research project in the US which has developed a new drug treatment.

Cataracts form when the lens inside the eye becomes cloudy. The only treatment is surgery to remove the cloudy lens but the US study identified the first drug treatment for cataracts in animals.

Elaine Howley of the National Council for the Blind in Ireland said that at any given time there were 80,000 people in Ireland who had cataracts and suffered a range of vision problems.

“There are nearly 30,000 operations for cataracts per year here and 50 to 60 people on a waiting list at any time, so anything that could help address that problem would be of huge benefit to their quality of life.”

The new drug was able to reverse lens clouding in dogs and it also worked with rabbit eye tissues, the researchers said.

Prevention

The treatment focuses on preventing the protein clumps that cause clouding of the lens, lead researcher Kang Zhang of the University of California, San Diego, said.

“The lens of the eye is mainly made from complex molecules called crystallins. It’s crucial that these fold in the correct way so they can stay transparent. This allows for clear vision. Although we don’t know exactly how, when the molecules don’t fold correctly they can clump together causing the lens to become cloudy,” he said.

In other parts of the body, molecules could fold incorrectly and clump together in similar ways, causing illnesses that included Alzheimer’s disease.

“We were studying families who had cataracts since birth and we found there was a defect in a protein in the cholesterol family called lanosterol. Then we saw that if you add lanosterol to cells it not only prevents cataract-forming protein clumps but also dissolves existing ones,” said Prof Zhang.