Intraoperative microkeratome complications in 47,094 laser in situ keratomileusis surgeries

PURPOSE: We evaluated the incidence and intraoperative microkeratome-related complications in laser in situ keratomileusis (LASIK). METHODS: We present non-randomized, retrospective, comparative, interventional case series. We reviewed the records of patients who underwent LASIK from August 2000 to March 2004 at Excimer Laser Santa Cruz, Sao Paulo, Brazil (47,094 eyes). We identified 369 eyes (0.0078%) with an intraoperative complication. Data were collected regarding microkeratome, average keratometric power, and type of complication. RESULTS: The Hansatome microkeratome was the most common microkeratome used (34,182 eyes; 73%), followed by the Automated Corneal ShaperACS (11,164 eyes, 24%) and the Nidek MK-2000 (1748 eyes, 3.7%). Intraoperative complications were more common with the ACS (1.26%) than with the Hansatome (0.63%) and MK-2000 (0.63%) (P < .001; P = .03; respectively). Complications included incomplete flaps (0.23%), buttonholes (0.13%), thin flaps (0.08%), and free flaps (0.08%). Buttonholes were more frequent with the ACS (0.34%) than with the Hansatome (0.06%) (P < .001) and free flaps were more common with the ACS (0.20%) and MK-2000 (0.29%) than with the Hansatome (0.04%) (P< .001). Keratometric power of eyes with intraoperative complications was significantly higher in the ACS group compared to the Hansatome group. CONCLUSIONS: Intraoperative complications were more common with the ACS than with the Hansatome or MK-2000. Buttonholes were most frequent with the ACS, and the Hansatome had the lowest incidence of free flaps.