Incidence of intraoperative flap complications in laser in situ keratomileusis.

PURPOSE: To evaluate the incidence of intraoperative flap complications in laser in situ keratomileusis (LASIK) and compare the incidence between eyes and between the Hansatome and Automated Corneal Shaper (Bausch & Lomb) microkeratomes.

SETTING: Open-access outpatient excimer laser surgical facility.

METHODS: A retrospective analysis was done of 84711 primary LASIK cases performed between November 1998 and May 2000 in 28 national open-access laser facilities. The intraoperative flap complications were identified and categorized into type of complication, eye involved, and microkeratome type. All cases used the Automated Corneal Shaper or the Hansatome microkeratome.

RESULTS: Two hundred fifty-six complications (0.302%) were identified: 29 failures to achieve intraocular pressure (0.034%), 84 partial flaps (0.099%), 59 buttonholes (0.070%), 74 thin or irregular flaps (0.087%), and 10 free flaps (0.012%). There were 134 right eye complications and 122 left eye complications (P =.45). No patient developed an intraoperative flap complication in both eyes. A comparison of Hansatome and Automated Corneal Shaper microkeratomes was possible for the cases performed between December 1999 and May 2000: 46 of 28 201 Hansatome procedures (0.16%) had a complication versus 21 of 329 Automated Corneal Shaper procedures (6.38%). This difference was statistically significant (P <.005).

CONCLUSION: The incidence of intraoperative flap complications during LASIK was acceptably small. The overall complication rate was similar in both eyes. The Hansatome was associated with a lower complication rate than the Automated Corneal Shaper.