Laser epithelial keratomileusis (LASEK) is a modified form of photorefractive keratectomy (PRK).
With LASEK, instead of removing the thin outer layer of the cornea (the epithelium) completely as in PRK, the surgeon cuts an area of the epithelium with a fine bladed instrument called a trephine. A dilute alcohol solution is then applied to loosen the cut epithelium. The surgeon then gently lifts and folds back the loosened epithelium, exposing the underlying corneal tissue for the excimer laser treatment.
The thin epithelium is then replaced once the laser reshaping is completed. To keep it intact and hold it in place, a bandage contact lens is applied. After 3 or 4 days, the bandage contact lens can be removed.
Like LASIK and PRK, LASEK can correct nearsightedness (myopia) and farsightedness, with and without astigmatism. Visual recovery after LASEK is generally faster than after PRK but slower than with LASIK. The same issues of post-operative discomfort and blurred vision that occur for a week or more after PRK can affect LASEK patients as well.