Evolution, techniques, clinical outcomes, and pathophysiology of LASEK: review of the literature

Laser subepithelial keratomileusis (LASEK) is a relatively new laser surgical procedure that combines certain elements of both laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) to improve the risk/benefit ratio. Diluted alcohol is used to loosen the epithelial adhesion to the corneal stroma. The loosened epithelium is moved aside from the treatment zone as a hinged sheet. Laser ablation of the subepithelial stroma is performed before the epithelial sheet is returned to its original position. We reviewed the literature regarding modifications of the technique, indications, outcomes, and complications, as well as wound healing after LASEK surgery. This literature review of 1,421 LASEK-treated eyes provided many findings: 1) The long-term stable results in the absence of serious complications, such as infections, recurrent erosions, scars, or late-onset corneal haze formation in patients re-examined up to 5 years after LASEK; 2) Epithelial closure with recovery of functional vision was completed at days 4 to 7 in most cases; 3) A tendency toward overcorrection with PRK nomograms; 4) We hypothesize that this tendency may be due to the decreased wound healing response, which may lead to myopic regression in PRK; and 5) Postoperative discomfort and prolonged visual recovery until the epithelium closes remain the biggest disadvantages of LASEK compared to LASIK. LASEK surgery is especially valuable in patients with thin corneas who would not qualify for LASIK surgery. However, a potential superiority of LASEK to LASIK in wavefront guided ablations still remains speculative.