Differences between LASIK and PRK

The primary difference between LASIK and PRK refractive surgery is that in LASIK, the vision correction occurs under a thin flap of the cornea, while in PRK, the vision correction is performed on the surface of the cornea after the epithelium has been removed. The epithelial cells then heal during the following three to four days, in order to cover the cornea.

Some providers believe that LASIK offers numerous advantages over refractive vision correction performed on the cornea’s surface (such as in PRK). There is often a more rapid improvement in vision and decreased discomfort with LASIK, since the surface epithelial cells have been preserved and do not need to heal or regrow. However, there are additional risks associated with the LASIK procedure.

In some patients, PRK is a safer alternative that may promise better outcomes. Patients who might benefit from PRK include those in whom the cornea might be too thin for LASIK, or in some patients with corneal irregularities or scars. Occupational demands may also make PRK a better option because flaps created during LASIK have potential to be disrupted after surgery. This risk decreases over time, and is rare.

A brief comparison of PRK and LASIK is outlined in the following chart:

Initial examination Similar to LASIK Similar to PRK
Procedural difference Surface epithelium removed Corneal flap made with femtosecond laser
Excimer laser procedure Similar to LASIK Similar to PRK
Postoperative discomfort Variable Usually minimal
Visual recovery Starts improving at three to five days Starts improving at one day
Possible side effects Glare/halo/ghosting/corneal haze Glare/halo/ghosting/corneal flap problems
20/20 or better uncorrected vision at 6 months 94.4% of patients 96.8% of patients
20/20 or better uncorrected vision at 12 months 94.7% of patients 96.7% of patients