Accuracy and reproducibility of Artemis central flap thickness and visual outcomes of LASIK with the Carl Zeiss Meditec VisuMax femtosecond laser and MEL 80 excimer laser platforms

PURPOSE: To quantify the accuracy and reproducibility of central flap thickness for flaps created with the VisuMax femtosecond laser system. METHODS: This was a prospective study of 24 eyes of 12 myopic LASIK patients. The VisuMax femtosecond laser was used to create flaps with an intended central flap thickness of 110 μm. Artemis 1 very high-frequency digital ultrasound scans were performed preoperatively and 3 months postoperatively. Central flap thickness was calculated as the addition of the preoperative epithelial thickness and the postoperative stromal component of the flap. Descriptive statistics (mean, standard deviation, minimum, maximum, and range) of central Reinstein Flap Thickness were calculated for all flaps. Central flap thickness accuracy was calculated as the difference between the mean and intended flap thickness. Reproducibility was evaluated as the flap thickness standard deviation between eyes. RESULTS: At 3 months, mean central Reinstein Flap Thickness was 112.3±7.9 μm (range: 102.6 to 132.9 μm). The accuracy was +2.3 μm and reproducibility was 7.9 μm. On average, the flap diameter was 0.47±0.21 mm greater than the intended flap diameter. CONCLUSIONS: The VisuMax femtosecond laser system was found to create flaps accurate to the intended thickness in the center with a low standard deviation, which will help reduce the risk of obtaining an excessively thick flap.