Advances in refractive surgery: microkeratome and femtosecond laser flap creation in relation to safety, efficacy, predictability, and biomechanical stability

Abstract

Methods of flap creation have changed over the years from the evolution of the mechanical microkeratome to the introduction of the IntraLase femtosecond laser keratome, both of which have different mechanisms of action to create corneal resections. Previous studies report the advantages and disadvantages of the mechanical microkeratome and the IntraLase femtosecond laser. The critical components in laser in-situ keratomileusis surgery remain the same, however: safety, efficiency, predictability, and biomechanical stability. Keratoectasia and flap efficiency remain a constant safety concern in laser in-situ keratomileusis surgery. Unexpectedly thick flaps as well as variable thickness continue to be a concern with safety in relation to microkeratome technology. Epithelial preservation, flap complications, and newer issues such as Transient Light Sensitivity Syndrome are safety concerns of flap creation. Improved outcomes with regards to vision, induced astigmatism, induced higher-order aberrations, and enhancement rates are seen to favor predictability of femtosecond technologies over the microkeratome. Recent biomechanical studies show improved healing with femtosecond laser flap creation compared with blade-assisted flap creation. The aim of this review is to summarize the key components for both the microkeratome and the femtosecond laser and to update on the recent advances reported on these topics.