Researchers bleach lens with laser, rather than remove it by
cataract surgery.
Cataracts are the
leading cause of blindness in the world, and are often related to aging. In a
common form of cataracts, proteins in the lens change over time, developing
chromophores — molecular add-ons that absorb color in the blue part of the
spectrum. Chromophores reduce the amount of light reaching the retina (and give
the lens a yellow-brown appearance), but they also disrupt the structure of the
lens proteins, causing light to scatter.
Cataracts can be
treated by lens-replacement surgery, but the procedure is invasive and costly,
requiring special equipment and skilled eye surgeons. To make cataract
treatment available to more people around the world, a less-invasive,
less-expensive technique is needed.
Line Kessel, an
ophthalmologist at Glostrup Hospital of the University of Copenhagen in
Denmark, and colleagues have come up with what they say is a promising
alternative to replacement surgery. In their approach, described in the
open-access journal PLoS ONE, they “bleach” the lens with a laser.
Ultraviolet light can
alter chromophores so they no longer absorb color, but UV light can damage the
retina. So the researchers use infrared light, delivered by an extremely
fast-pulse laser. The pulses are so fast, Dr. Kessel said, that two photons hit
a target molecule simultaneously, with the same effect as if UV light was used.
