Excimer laser photorefractive keratectomy for farsightedness (H-PRK)

Surgery Overview

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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

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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

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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

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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

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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

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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.

References

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Citations

1. American Academy of Ophthalmology (2002). Refractive Errors (Preferred Practice Pattern). San Francisco: American Academy of Ophthalmology.

2. Ge J, et al. (2001). Surgical correction of hyperopia: Clear lens extraction and laser correction. Ophthalmology Clinics of North America, 14(2): 301–313.

Credits

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Author	Kathe Gallagher, MSW
Editor	Kathleen M. Ariss, MS
Associate Editor	Michele Cronen
Associate Editor	Tracy Landauer
Primary Medical Reviewer	Martin Gabica, MD - Family Medicine
Specialist Medical Reviewer	Carol L. Karp, MD - Ophthalmology
Last Updated	December 19, 2005