The use of the femtosecond laser in the customization of corneal flaps in laser in situ keratomileusis

PURPOSE OF REVIEW: With a growing body of work that examines the biomechanical response of the cornea following flap creation, a case has developed for creation of flaps that take advantage of the inherent strength of the stromal layers of the cornea. These flaps are thinner (+/-100 microm) and the diameter is based on the maximum ablation zone of the excimer laser. The critical component in this approach is the use of the IntraLase Femtosecond Laser (IntraLase, Irvine, California, USA) as it is the only keratome currently capable of achieving a customized flap. RECENT FINDINGS: Concern over the thickness of the corneal flap has led to a resurgence of surface ablation in order to preserve as much corneal tissue as possible. Although surface ablation does offer a higher degree of safety versus laser in situ keratomileusis (LASIK), it does not achieve the same visual results during early postoperative recovery or a high degree of patient satisfaction. New biomechanical studies comparing corneal response to various types of laser refractive procedures demonstrate that corneal flaps created with a femtosecond laser are the most stable. SUMMARY: This review is intended to summarize the primary advantages of a customized corneal flap in LASIK, as well as to review the biomechanics that support this approach.