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The
most recent development in vision correction is a procedure called
Photorefractive Keratectomy ( PRK.) The Procedure is similar to RK, in that the
cornea is modified to correct vision, the process is enormously different with a
remarkable improvement in patient risk and correction capabilities.
Rather than making cuts in the cornea, the PRK process uses an excimer laser to
shape an area approximately 4 to 8 millimeters in diameter on the surface of the
eye. The process removes only 5 to 10% of the thickness of the cornea for mild
to moderate myopia and up to 30% for extreme myopia. The major benefit of the
PRK procedure is that the integrity and strength of the corneal dome is
retained. The excimer laser is set at a wavelength of 193nm, which can remove a
microscopic corneal cell layer without damaging any adjoining cells. This allows
the surgeon to make extremely accurate and specific modifications to the cornea
with little trauma to the eye.
This ability to shape, rather than cut the cornea, expands up the arena for
treating additional vision conditions. |
