Photorefractive keratectomy (PRK) and laser epithelial keratomileusis (LASEK) for farsightedness use a laser to reshape the cornea so that light is refocused on the retina. The laser reshapes the cornea accurately without damaging nearby tissues. No surgical cut is needed. Either procedure may be used to correct farsightedness and astigmatism at the same time.
These procedures can be done on an outpatient basis in a surgeon's office or same-day surgery centre.
With PRK, surface skin cells of the cornea are removed, and a laser is used to reshape the cornea. The whole procedure, including preparation and surgery, takes about 20 minutes.
With LASEK, the surface layer of the cornea is loosened and pushed to the side. After the laser reshapes the cornea, the surface layer is placed back over the cornea.
PRK and LASEK are sometimes called surface ablation.
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.
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. Recovering from LASEK surgery may not be as painful as with the PRK procedure.
Why It Is Done
PRK and LASEK are similar surgeries and are done for similar reasons. Both are elective, cosmetic procedures, done to correct farsightedness in otherwise healthy eyes. Your doctor will let you know if you need PRK or LASEK instead of the more common LASIK procedure.
PRK or LASEK 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.
How Well It Works
PRK and LASEK effectively reduce mild to moderate farsightedness. Little is known about the long-term effectiveness of either procedure.
In the short term, PRK has proved effective in correcting mild to moderate hyperopia.
One problem commonly associated with PRK is clouded vision (sometimes referred to as haze). Most eyes treated with PRK have some clouding of the cornea as a result of healing. Your doctor may prescribe a medicine that will help take away the haze. But sometimes the haze won't go away.
Other complications of 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. Medicines are sometimes used to control and limit regression.
Serious but rare complications may include:
- Elevated pressure inside the eye (intraocular pressure) and glaucoma.
PRK is considered safe. Serious complications are rare. But PRK is a relatively new procedure, and it may have long-term side effects or complications that are not yet known.
LASEK has similar risks to PRK. Also, there is a risk of the epithelial flap coming loose after surgery and causing pain.
What To Think About
If you are thinking about having surgery to improve farsightedness, you may have a number of options. Talk with your doctor about all the options, including their benefits and risks.
Although PRK and LASEK are viable options for correcting farsightedness, LASIK is the preferred procedure because of its quicker healing time and quicker visual recovery.
Both PRK and LASEK are cosmetic procedures. The cost of refractive surgery varies. Provincial health plans and most insurance companies do not cover the cost of refractive surgery.