A site for sore eyes
News release from Australian National Science Week
Australian eye researchers are close to achieving what may be the perfect
contact lens - one that can be left implanted in the eye indefinitely.
Debbie Sweeney of the Vision Cooperative Research Centre says that
clinical trials of the breakthrough technique will start within two years.
"The implantable contact lens, or corneal onlay, has been a research goal
for many years," says Sweeney. "We've been able to develop our implantable
lens because of the wide range of expertise which we could bring together
in the Vision CRC. "We needed specialists in novel polymers, in the
physics and chemistry of surfaces, in optical design and even in glues and
adhesives," she says. "Then we needed cell biologists to understand the
reaction of living to non-living tissue, and to monitor the movement of
nutrients and oxygen within the eye itself. "And of course we will also
depend on human volunteers to allow us to fine-tune the technique of
implanting the lenses in living human eyes."
Sweeney says the technique involves gently removing the outer layer of
skin on the cornea, and inserting a flexible polymer implant with a
special adhesive backing. "In fact it is quite a simple surgical operation
which can be finished in twenty minutes," she says. "This is far less
invasive than corrective laser surgery, and it is also - if necessary - an
easily reversible procedure. "A successful implant may have a life of
between ten and twenty years," she says. "The epithelial cells of the
eye's skin quickly grow over the surgical site, and the polymer lens
itself is biostable - that is, it has no reaction to its living
environment - and does not absorb anything from the surrounding material.
It is also porous, allowing the necessary passage of the liquids and
nutrients of the eye." She adds that this research answers a problem which
has challenged eye and vision specialists for many years and will make
contact lenses truly competitive with spectacles.
"Even in the nineteenth century, experimenters attempted to implant "Plexiglass"
into the cornea, but this was inevitably rejected by the eye of the host,"
she says. "More recently, there has been some success with 'donated'
corneas being sewn into the eye, but with these too there has been a
continuing problem of rejection. "It has been the development of the right
polymer, optically clear, porous and biostable, by our research team,
which has made the long-term implant possible," she says. Researchers from
CSIRO Molecular Sciences, Institute for Eye Research and Vision CRC form
this team. Sweeney says that the implantable contact lens will be
particularly important to patients with eye problems, who would otherwise
be considering laser refractive surgery - an invasive and non-reversible
procedure.
Coming in Issue 74:
Accidents will happen - human reactions to chemicals and biological
reagents can end a career
Predicting climate change - As carbon dioxide levels double, what will
really happen the day after tomorrow?
Also in
Issue 73, September 2004:
Green silicon production
- making the microelectronics industry favourite element
P2P for scientists - peer mentoring,
helping students help each other
Women in science - smashing the glass
ceiling
Academic poaching of researchers -
plugging the brain drain
Permanent implantable contact lenses -
does what it says on the tin
Profile of ETH Zurich - a profile
of...
Paradoxical ozone - the paradox of
ozone
Previous, previous article - The elements
that make up our bodies
Back to the sciencebase.com home page
Read the Chymical Wedding List - bonus feature
in Issue 71 of Elemental Discoveries; we've also got a new feature listing
the
elemental discoveries timeline.