| The word "laser" is an acronym
for Light Amplification by Stimulated Emission of Radiation.
A laser is a concentrated beam of light, created when
an electrical current passes through a special material.
Used in eye surgery since the 1970's, the laser is popular
for its unparalleled degree of precision and predictability.
Lasers are being used for an increasing variety of eye
diseases.
A laser's specific wavelength allows energy to be absorbed
in selected tissues and not damage surrounding tissues.
The laser beam is so precise it can cut notches in a
strand of human hair without breaking it.
Thermal lasers convert light to heat. This type of
laser seals blood vessels and destroys abnormal tissues.
Photoablative lasers cut or sculpt tissue and are used
to remove tissue, changing the shape and surface of
the eye.
Lasers can preserve vision, sometimes for many years,
for diabetics with diabetic retinopathy. In treating
diabetic retinopathy, the laser light seals leaking
blood vessels in the retina, the light-sensitive layer
of cells lining the back of the eye. Lasers also treat
more unusual retinal disorders, including blood vessel
problems and tumors.
Also used to treat glaucoma, lasers can create a new
passage through the iris to relieve eye pressure or
open the eye's blocked drainage canals.
Although lasers do not remove cataracts, they may one
day. Right now, they open the posterior capsule, which
often becomes cloudy after cataract surgery, restoring
vision in a matter of hours.
More recently, the excimer laser has received a great
deal of attention as a tool for permanently correcting
refractive errors such as nearsightedness, farsightedness
and astigmatism. Refractive laser surgery can decrease
or eliminate the need for glasses and contact lenses
by reshaping the cornea. |
