Laser Epithelial Keratomileusis (LASEK), also called no-cut LASEK, is essentially LASIK without a flap. With the eye under a local anesthetic, the doctor applies a diluted alcohol solution to the epithelium (the surface layer of the cornea), loosening it from the stroma (the tissue beneath). The loosened epithelium is placed to one side and laser energy is applied to the stroma, using the same parameters to reshape the cornea as in LASIK surgery. After the completion of the laser treatment, the epithelium is repositioned. A contact lens is placed on the cornea for several days to aid in healing and comfort. During the few days required for healing, the eyes can be sensitive to light and uncomfortable.
Photo-Refractive Keratectomy (PRK) is another method of surgically reshaping the cornea using the excimer laser. The primary difference between PRK and LASEK is that for PRK, the surface epithelium is removed entirely in the area of treatment, whereas in LASEK, the epithelium is pushed to the side after being loosened with alcohol and repositioned after laser treatment. In both procedures, healthy corneal cells grow over the treatment zone from the periphery of the cornea towards the center. A contact lens is applied after surgery to improve comfort. During the few days required for healing, the eyes can be sensitive to light and uncomfortable.