DEC 09, 2011
Epithelial ingrowth is a frequent complication following LASIK enhancement using the manual dissection technique. Because the incidence of epithelial ingrowth is lower in femtosecond laser-created flaps compared with mechanical microkeratome flaps, Jose L. Guell and colleagues developed a new enhancement technique for microkeratome-created flaps using the femtosecond laser.
Using a femtosecond laser (Visumax, Carl Zeiss Meditec AG), they created a vertical side cut incision 1.2 mm smaller than the original flap diameter. The flap is 10 µm thicker than the original peripheral flap thickness measured by anterior segment OCT, and the side cut angle is 90 degrees. The position of the hinge is the same as in the original flap, and the hinge angle is 50 degrees.
The flap edge created by this technique is clean and smooth. Moreover, the vertical configuration of the side cut is believed to be the ideal morphology to prevent epithelial cell migration. These two factors may decrease the risk for epithelial ingrowth after LASIK enhancements, according to the study's authors.Using this technique in 84 eyes, they have observed no cases of epithelial ingrowth. This represents a promising new technique that deserves study in a prospective, case-control manner.