PRK (photorefractive keratectomy)
PRK, or photorefractive keratoplasty, was the original refractive
surgical procedure approved by the FDA in 1995. This procedure is performed
on the corneal surface without making a flap with a keratome. The superficial
tissue, called the epithelium, is removed with a rotating brush and the the Visx
laser is used to reshape the surface. A bandage contact lens is then placed on
the cornea for 2-4 days and the epithelium is allowed to heal over. There is
usually a little more discomfort with PRK as compared to Lasik although this is
quite variable among patients. The vision usually takes longer to recover and
stabilize but after about a month, both procedures yield equivalent visual results,
and sometimes even better with PRK. PRK can be performed on both eyes on the same
day but often times the eyes are done on separate days due to the delayed visual
recovery. PRK can also be combined with the wavefront guided system on the Visx
laser to perform custom treatments.
Even though PRK is an older procedure, it is still ve ry useful and many
ophthalmologists including Dr. Hendricks use it more today than they did several
years ago. First of all, since no flap is made, the risk is automatically decreased
because the potential problems associated with the making and healing of the flap are
avoided. Another indication for PRK is that some patients have thin corneas and PRK
is safer than Lasik in many of these situations. If an enhancement procedure is
needed more than 2 or 3 years after Lasik, Dr. Hendricks will often use PRK since
the flap is tightly sealed--this will avoid the complication of epithelial ingrowth
where surface epithelial cells grow under the Lasik flap. One last indication would
be for any refractive error involving hyperopia, or far-sightedness--PRK seems to give
a better long term result for hyperopia than Lasik does.
In summary, even though PRK is considered an older technology, it is still quite useful
and is recommended over Lasik in many circumstances. Dr. Hendricks uses it frequently
and he will help you decide if it would be the procedure of choice in your particular
situation.
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