The laser eye procedures PRK, LASEK and epi-LASIK

The first laser eye surgery performed on humans was photorefractive keratectomy (PRK) using the excimer laser. It was performed for the first time in 1987 and is therefore considered as the first generation of laser eye surgery. With this laser technique, the corneal epithelium is removed mechanically beforehand either using a scalpel, alcohol, a microkeratome or a laser. Then, the top corneal layer underneath is reshaped using an excimer laser. After the laser procedure, a bandage must be worn for several days until the epithelium has regenerated.

The largest drawback is the safety profile: In comparison to the laser techniques that followed, all PRK methods have three things in common: postoperative pain for approx. 4 days, an increased risk of infection and slow vision recovery over 4-6 weeks. For these reasons, we recommend our patients only in exceptional cases having their eyes lasered using these obsolete methods.

With laser eye surgery using LASEK (laser-assisted sub-epithelial keratectomy), the epithelium is pre-treated with alcohol, detached manually using special instruments, lifted off and folded away. After the laser surgery, the epithelium is repositioned. The pre-treatment of the epithelium with alcohol can impair healing. A bandage contact lens must be worn for 1 to 3 days, the pain is somewhat less than with PRK and visual acuity is supposed to return quicker.

Laser eye surgery using Epi-LASIK (epithelial LASIK) is another advanced variant of PRK which involves less risks than LASIK. With this laser eye surgery technique as well, the entire epithelial sheet is lifted off and folded away to be returned to its original position after the surgery. However, in this case, a similar microkeratome is used as for LASIK. This means that there are no alcohol-related healing impairments as with LASEK but there is a risk of miscuts. In this case as well, visual acuity is supposed to return more quickly.

The higher risk is due to the cut using the microkeratome. With Epi-LASIK, the epithelial sheet is cut using a microkeratome. This means that there is a risk of a miscut which cannot be corrected anymore. We therefore do not recommend Epi-LASIK.