LASEK (laser epithelial keratomileusis) is a modified form of PRK (photorefractive keratectomy); this procedure requires the surgeon to loosen the outer layer of the cornea, called the epithelium. Unlike PRK, the epithelium is not removed in LASEK. The surgeon instead folds back the loosened epithelium so that the laser can reshape the exposed cornea. After the laser treatment, the surgeon replaces the “flap” of epithelium over the corneal bed and places a bandage soft contact lens on top. Visual recovery after LASEK is generally faster than in PRK but slower than in LASIK.
Unlike the LASIK procedure the epithelial layer is not connected to the cornea with a hinge, thus it can be difficult keeping the flap in the exact position it was in prior to the procedure and it may be easily dislodged or moved. The flap and hinge technique created during the LASIK procedure allows the surgeon to precisely replace the flap in its original position and allows for a permanent point of connection to the cornea.
Currently, the use of the excimer laser for LASEK is not FDA-approved. This means that surgeons are not supposed to advertise this procedure unless they are enrolled in a clinical trial. Although the number of LASEK procedures are small compared to LASIK, early results show this procedure is promising. Nevertheless, additional studies will be necessary before LASEK is widely accepted as a viable procedure among corneal surgeons. To date, LASEK has not proven itself to the extent of LASIK.