Femtosecond laser-assisted retreatment for residual refractive errors after laser in situ keratomileusis

PURPOSE: To study the utility of creating an additional side cut within the old laser in situ keratomileusis (LASIK) flap using a femtosecond laser to reduce the incidence of epithelial ingrowth in patients having retreatments for residual refractive errors after LASIK. SETTING: Bascom Palmer Eye Institute, Miller School of Medicine, Miami, Florida, USA. DESIGN: Comparative case series. METHODS: On a chart review of all cases that had retreatment between January 2004 and April 2011, eyes in which an additional side cut with the femtosecond laser within the old LASIK flap margin was created were classified as Group 1. All eyes having retreatment using traditional flap-relifting techniques between January 2008 and April 2011 were classified as Group 2. RESULTS: Twenty-four eyes of 18 patients had femtosecond laser assisted retreatment with side cut only (Group 1), while 103 eyes of 80 patients had a flap-lift LASIK enhancement (Group 2). Twenty-seven cases of epithelial ingrowth were identified in the 2 groups, 4 cases (17%) in the side-cut group and 23 cases (22%) in the flap-lift group. There was a statistically significant difference between the 2 groups in the incidence of epithelial ingrowth in patients in which the microkeratome was used as the initial method of flap creation (P<.05). CONCLUSION: Femtosecond laser assisted side-cut LASIK resulted in a statistically significant lower incidence of epithelial ingrowth after stratification because of the higher risk for epithelial ingrowth in patients who had primary LASIK with microkeratome flaps.