12 August 2003

from the University of New South Wales Australia

Dr Arthur Ho

The recently established Vision Cooperative Research Centre is developing a strategy to replace the hardened lens of ageing eyesight and restore natural vision.

The eye's lens focuses by changing shape. When muscles in the eye relax, the lens is pulled flat to focus on distant objects. When the same muscles contract, the lens returns to a plumper shape, bringing closer objects into focus.

But as the eye ages, the lens hardens, preventing it reforming into its broader shape. The lenses of 40-year-old people have only a quarter of their capacity to change shape, or accommodate, as they did at birth. After the age of 45, most people will need glasses or bifocal contact lenses for reading. Rapid growth in the over-45 year age group means that presbyopia will soon affect over 40% of the population.

The Vision CRC has targeted presbyopia as a growing area of need. Dr Arthur Ho, director of the Vision CRC Presbyopia Program, is part of an international group of researchers developing a flexible gel lens to replace the older hardened lens, restoring the eye's ability to focus up close.

"We see it being used initially as an improvement to current cataract surgery," Dr Ho said. "But once it is shown to be safe and effective, we think that more and more younger people who are starting to need reading glasses will adopt it as well."

Implanting the gel would be similar to current cataract surgery, although the lens is not replaced. After making a small incision in the cornea, the surgeon would cut a tiny hole in the lens capsule and remove the contents. The gel, which has the consistency of thick oil, is pumped in and a burst of UV or visible light transforms it into a jelly. "This could be a quick, 15-minute procedure," says Dr Ho.



     Listing # 12 August 2003