Surgery Overview
Photorefractive keratectomy for
hyperopia (H-PRK) is a newer and more difficult
procedure than PRK for nearsightedness (myopia). H-PRK uses a laser to reshape
the cornea
so that light is refocused on the
retina
. The laser reshapes the cornea accurately
without damaging nearby tissues.
H-PRK may be used to correct farsightedness and
astigmatism at the same time.
H-PRK is performed on an outpatient basis in a surgeon's office or
same-day surgery center. The surface skin cells of the cornea are removed, and
a laser is used to reshape the cornea. Unlike LASIK, no flap is cut. The H-PRK
procedure is similar to PRK for myopia, but the laser portion takes a little
longer, an average of about a minute or a minute and a half. The whole
procedure, including preparation and surgery, takes about 20 to 30 minutes.
What To Expect After Surgery
You will wear an eye shield, a bandage, or special contact lens for
2 to 3 days after surgery, and your doctor will prescribe eyedrops to reduce
inflammation and the risk of infection. You may need to use eyedrops for
several months after surgery. Several follow-up visits are needed.
Recovery from H-PRK is longer and more painful than recovery from
hyperopic laser-assisted in-situ keratomileusis (H-LASIK). The eye can be quite
painful for 2 to 3 days. Your vision will be reduced for several days after
surgery, until the surface skin cells heal.
Why It Is Done
The American Academy of Ophthalmology considers H-PRK safe and
effective for mild to moderate farsightedness. Specifically, the surgery has
been approved for use in the United States in people age 21 and older who have
farsightedness of 1.0 to 6.0
diopters.1
H-PRK may not be appropriate for people who have more severe
farsightedness (high hyperopia) because the results are harder to predict and
complications are more likely.
H-PRK is an elective, cosmetic procedure, done to correct
farsightedness in otherwise healthy eyes.
The procedure may not be done during pregnancy, because pregnancy
may interfere with the healing of the cornea.
How Well It Works
Photorefractive keratectomy for hyperopia was approved in the U.S.
in 1998. Since it has been in use such a short time, little is known about its
long-term outcomes. Research is under way to determine the long-term safety and
effectiveness of the procedure.
In the short term, H-PRK has proven effective in correcting mild to
moderate hyperopia. One clinical trial showed that one year after surgery, 92%
of people who had the procedure had 20/40 vision or better, and 95% were within
1.0 diopter of the intended correction.2
Risks
One problem commonly associated with H-PRK is clouded vision
(sometimes referred to as haze). Most eyes treated with H-PRK have some
clouding of the cornea as a result of healing.
Other complications of H-PRK may include:
- Night vision problems, such as halos (often
described as a shimmering circular zone around light sources such as headlights
or streetlights).
- Glare, or increased sensitivity to bright
light.
- Double vision (diplopia), usually in one
eye.
- New astigmatism.
- Regression. As the cornea heals,
cells may fill in the area that was reshaped by the laser, causing at least
some of the farsightedness to come back. Regression may also occur if the
treated area thickens as part of the healing process. Regression may occur up
to 2 years after surgery. Medications are sometimes used to control and limit
regression.
- Slow recovery of best corrected vision.
Serious but rare complications may include:
- Infection.
- Elevated pressure inside
the eye (intraocular pressure) and
glaucoma.
H-PRK is considered safe. No deaths have been reported as a result
of the operation, and serious complications are rare. However, H-PRK is a
relatively new procedure, and it may have long-term side effects or
complications that are not yet known.
What To Think About
If you are considering having surgery to improve farsightedness,
consider the different options (H-LASIK, H-PRK, LTK, and intraocular lens
implants) and discuss them with your doctor.
Although H-PRK is a viable option in the correction of
farsightedness, H-LASIK is becoming the preferred procedure because of its
quicker healing time and quicker visual recovery.
H-PRK is a cosmetic procedure. The cost of refractive surgery
varies in different locations, but it can be a significant expense. Most
insurance companies do not cover the cost of refractive surgery.
Complete the
surgery information form (PDF)
(What is a PDF document?)
to help you prepare for this surgery.