The Comparison of Corneal Ablation Amount by MEL-60 Excimer Laser and Schwind Multiscan Excimer Laser Systems

ABSTRACT

PURPOSE: The expected corneal ablation amount was compared to the achieved corneal ablation amount in two different excimer laser systems. METHODS: One hundred twenty eyes were recieved Laser In Situ Keratomileusis (LASIK) for the correction of myopia. LASIK was performed with MEL-60 excimer laser and Schwind Multiscan excimer laser system. The central corneal thickness was measured preoperatively, 1 week and 1 month postoperatively by using ultrasonic pachymetry. RESULTS: In eyes with MEL-60 excimer laser, the average expected corneal ablation amount was 81+/-26micro meter and average achieved corneal ablation amount at postoperative one week was 65+/-26 micro meter. There was statistical difference between expected and achieved ablation amount. (p<0.001, paired samples test) In eyes with Schwind Multiscan excimer laser, the average expected corneal ablation amount was 69+/-25 micro meter and average achieved corneal ablation amount at postoperative one week was 69+/-25 micro meter. There was no statistical difference between expected and achieved ablation amount (p=0.761, paired samples test). CONCLUSIONS: The pachymetry at postoperative one week appears to be an useful method to measure the real corneal ablation amount by LASIK with various excimer lasers. Residual stromal bed thickness after LASIK can be presumed, and it helps to decide modality of retreatment.