PRK / Epi-LASIK

Photorefractive Keratotomy (PRK) was the first laser procedure approved by the FDA. During the PRK procedure, the surface cells of the cornea (known as the epithelium) are polished from the cornea using one of a number of different polishing instruments. The excimer laser is then used to sculpt the Bowman’s layer and the front surface of the cornea. Following PRK the epithelium takes three to ten days to resurface the eye. This healing time variation depends upon a number of factors such as: the size of the area treated; the health of the patient’s underlying epithelial cells; individual variability in healing rates, and the toxicity of certain medication which are applied to the surface of the cornea after PRK. Following PRK, in every case, a bandage contact lens is placed on the eye to act as a splint to assist in the healing and to make the eye more comfortable.

LASEK (not a misspelling of LASIK) is a modification of the PRK procedure. LASEK varies in the following way. Once the eye is anesthetized, a few drops of a very weak alcohol solution are applied to a central circumscribed area on the surface of the cornea for about 30 seconds. This weak alcohol solution loosens the epithelial layer allowing it to be peeled back in a sheet, thereby exposing the underlying Bowman’s layer. In LASEK, once the epithelial cells have been laid out of the way, the laser is applied to Bowman’s layer in the exact same fashion as in PRK. Once the laser treatment has been completed, the epithelial layer is laid back into place and a soft contact lens is placed over the eye as in PRK.

Essentially, LASEK and PRK are identical, except for the fact that following the application of the laser in LASEK, the epithelial cells are laid back over the treatment area and may serve to facilitate healing of new epithelium.