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Excimer Laser Surgery for Myopia
Laser light is capable of performing surgical procedures too delicate for the
finest scalpel. This makes laser light the ideal tool to use on the eye. The
term "laser" is an acronym for "Light Amplification by Stimulated Emission of
Radiation," which is the scientific description of the method for creating this
intense beam of light.
The excimer laser uses a mixture of argon and fluorine gases to
produce a slender beam of invisible ultraviolet light energy. This ultraviolet
light has a much shorter wavelength than the ultraviolet light in sunlight
that causes sunburn.
The excimer laser does not burn the eye. It removes only 1/4 of a
micron (an amount invisible even with a normal examining microscope,
representing about one ten-millionth of an inch) of cornea with each pulse.
The excimer laser energy first breaks up the molecular bonds in the
cornea's collagen connective tissue, and then scatters the small molecules
into the air. This process is call photo-ablation.
In laser vision correction, the excimer laser is used to reshape
the curvature of the eye so that light becomes focused crisply on the
retina. This can reduce your dependency on glasses or contact lenses. The
reshaping may be carried out in one of two ways: on the surface of the
cornea, with photorefractive keratectomy (PRK), or under the surface of the
cornea, with laser in-situ keratomileusis (LASIK).
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