Photorefractive keratotomy, or PRK, is a type of laser eye
surgery used to correct mild to moderate nearsightedness,
farsightedness, and/or astigmatism.
All laser vision correction surgeries work by reshaping the
cornea, or clear front part of the eye, so that light traveling
through it is properly focused onto the retina located in the back
of the eye. There are a number of different surgical techniques
used to reshape the cornea. During PRK, an eye surgeon uses a laser
to reshape the cornea. This laser, which delivers a cool pulsing
beam of ultraviolet light, is used on the surface of the cornea,
not underneath the cornea, as in LASIK.
What are the advantages of PRK?
PRK is highly
accurate in correcting many cases of nearsightedness. Approximately
80% of PRK patients have 20/20 vision without glasses or contact
lenses one year after the surgery; 95%-98% have 20/40 or better
without glasses or contacts.
What are the disadvantages of PRK?
Disadvantages of
PRK include:
- Mild discomfort, including minor eye irritation and watering,
for 1 to 3 days following the procedure.
- It is expensive, typically costing as much as LASIK (around
$2,200 to $2,250 per eye).
- Somewhat longer time to best uncorrected vision (best vision is
vision attained using glasses or contacts). Typically, patients are
80% at 1 month after surgery, and 95%-100% by 3 months after
surgery. LASIK, in contrast, corrects vision much faster.
- The outcome is not completely predictable and some patients may
still require glasses.
What are the potential side effects of PRK?
Many PRK
patients experience some discomfort in the first 24 to 48 hours
after surgery, and almost all experience sensitivity to light.
Within the first six months after surgery, other potential side
effects may include:
- Loss of best vision achieved with glasses
- Seeing a minor glare. This can be permanent, depending on a
patient's pupil size in dim light.
- Mild halos around images
How do I prepare for PRK surgery?
Before your PRK
surgery, you will meet with a coordinator who will discuss with you
what you should expect during and after the surgery. During this
session, your medical history will be evaluated, and you will have
your eyes tested. Likely tests will include measuring corneal
thickness, refraction, and pupil dilation. Once you have gone
through your evaluation, you will meet the surgeon, who will answer
any further questions you may have. Afterwards, you can schedule an
appointment for the PRK procedure.