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PRK
PRK is performed with an
extremely precise computer-assisted laser. Before its approval,
ophthalmologists thoroughly researched and tested this procedure
from 1989-1995, meeting the strict guidelines of the federal Food
& Drug Administration. PRK uses
the excimer laser to reduce or alter the shape of the cornea so
light rays can focus sharply on the retina. The laser sculpts
the cornea's surface by using a cold light beam to remove cell
tissue from the cornea's surface-one molecular layer at a time.
The procedure is done by first, anesthetizing
the cornea with drops, creating a surgical abrasion down to the
corneal stroma, then ablating (i.e. removing) the corneal tissue
with the laser.
The disadvantages of PRK over LASIK are that
some patients have significant discomfort and/or pain for 24-48
hours afterward. The technique creates a significant corneal abrasion
that leaves vision fairly blurred for 2-5 days and therefore makes
a bilateral procedure on the same day, ill advised. For patients
with thin corneas, mild myopic corrections, corneal surface disease,
or great fear of flap creation from the LASIK procedure, PRK gives
generally excellent and similar visual results as LASIK and may
be preferable for some patients.
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Excimer beam striking surface of cornea
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What You Should Know >
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