Analysis of Decentration after LASIK with Two Eye-Trackers

ABSTRACT

PURPOSE: To evaluate the efficacy of two excimer laser systems with eye-tracker in the term of decentration amount. METHODS: We performed LASIK with LaserScan LSX(TM) (group 1, 39 eyes) and Allegretto Wave(TM) (group 2, 94 eyes), both of which were equipped with eye-tracker. The amount of decentration was measured on a difference map that was obtained from preoperative and postoperative corneal topography, and was compared between the two groups. RESULTS: The amount of decentration was significantly higher in group 1 (0.39 +/- 0.22 mm) than in group 2 (0.29 +/- 0.18 mm) (p=0.018). When these groups were subdivided by preoperative spherical equivalent, in case of under -6.0 D, the amount of decentration between the two groups (0.31 +/- 0.16 mm in group 1, 0.28 +/- 0.15 mm in group 2, p=0.380), whereas in case of over -6.0 D, the amount of decentration was significantly higher in group 1 (0.48 +/- 0.26 mm) than in group 2 (0.30 +/- 0.21 mm) (p=0.020). CONCLUSIONS: Allegretto Wave(TM) showed better centration ability than LaserScan LSX(TM) and this superiority was more profound in highly myopic eyes.