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LASIK Up-to-date Newsletter
Eye Laser: Technology with the highest precision
Not even the most skillful micro surgeon, with the best scalpel can
work as accurately or precise as the Excimer Laser that is used in LASIK,
and also in PRK. Its development at the end of the 70’s helped
with the breakthrough of refractive surgery.
The Excimer Laser is a cold laser. Its radiation exhibits ideal characteristics
for use at the cornea, since the energy is absorbed in a layer that
is only 1/1000 of a millimeter thick. This evaporates the biological
tissue instantaneously, without affecting the layers of cells underneath.
One laser pulse removes 0.25 micrometer of tissue. Cornea tissue with
a thickness of 10 – 15 micrometer ( approximately 1/100 millimeter)
must be removed for each diopter to be corrected. For comparison: a
human hair is approximately 70 micrometer thick.
The Excimer Laser has been continuously improved and developed.
From the “broad beam” laser, which worked on the entire
cornea surface, the so-called “flying spot” lasers were
developed. They probe the cornea with a smaller laser beam, only 1-2
mm wide. They have a feedback mechanism that registers exactly where
the laser was already effective. As a result, multiple treatments of
the same areas, or overlapping are avoided.
By combining this with cornea topography, which shows the fine, individual
irregularities of the cornea surface, the laser spots can now selectively
target the cornea for treatment. This form of treatment is also called
“customized ablation”, or Topo-Link-LASIK. This process
is approximately 10 -15% more accurate than the standard treatment,
since it optimizes the image quality at each spot of the cornea.
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