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
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 be less painful than from PRK.
Why It Is Done
PRK and LASEK are procedures done to correct farsightedness in otherwise healthy eyes.
They may not be a good choice for people who have more severe farsightedness (high hyperopia). That's because the results are harder to predict and complications are more likely.
These procedures may not be done while you are pregnant. Pregnancy may interfere with the healing of the cornea.
How Well It Works
PRK and LASEK work well to reduce mild to moderate farsightedness. But experts don't know how long the effects will last. In the short term, PRK has proved effective in correcting mild to moderate hyperopia.
The risks associated with PRK, LASEK, and epi-LASIK for nearsightedness and farsightedness are similar.
The most common problem is clouded vision (sometimes also called haze). Some people's eyes have some clouding of the cornea as a result of healing. This clouding may occur within a year after surgery and then clear up. It has been linked with spending a lot of time in the sun. Clouding appears to be more common in people who are very nearsighted. Some doctors may give you eyedrop medicine during or after the surgery to lower the chance of haze.footnote 1
Some doctors may recommend avoiding direct sunlight for a while after your surgery. They may also advise you to take vitamin C and wear sunglasses.
Other complications of these surgeries may include:
- Night vision problems, such as halos. (These are often described as a shimmering circle around light sources such as headlights or street lamps.)
- Glare, or being more sensitive to bright light.
- Double vision (diplopia), usually in one eye. Some people describe this as "ghosting" around an object, rather than a doubling.
- New astigmatism.
- Overcorrection or undercorrection.
- Regression. As the cornea heals, cells may fill in the area that was shaped by the laser. This can cause at least some of the nearsightedness 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. Some doctors suggest medicines to limit it.
- Loss of best corrected vision, which is the best possible vision you can achieve using glasses or contact lenses. This loss isn't common. But the risk rises with severe nearsightedness.
You may get treatment again if you end up with nearsightedness caused by undercorrection or regression.
Serious but rare complications may include:
- Sores (ulcers) on the cornea.
- Elevated pressure inside the eye (intraocular pressure) and glaucoma.
Experts don't yet know about all of the long-term side effects or complications.
- Jain S, et al. (2014). Excimer laser photorefractive keratectomy. In M Yanoff, JS Duker, eds., Ophthalmology, 3rd ed., pp. 95–101. Edinburgh: Mosby Elsevier.
Current as of: January 24, 2022
Current as of: January 24, 2022
Jain S, et al. (2014). Excimer laser photorefractive keratectomy. In M Yanoff, JS Duker, eds., Ophthalmology, 3rd ed., pp. 95–101. Edinburgh: Mosby Elsevier.