Abstract: Objective To compare the short-term influence on the corneal endothelium cells after femtosecond lenticule exraction (FLEx) and femtosecond laser in situ keratomileusis (FS-LASIK). Design Prospective comparative case series. Participants Two hundreds eyes of one hundred consecutive patients were enrolled in this prospective study and divided into two groups: FLEx group (100 eyes of 50 patients) and FS-LASIK group (100 eyes of 50 patients). Methods Preoperatively, and at 1 day, 3 days, 1 week and 1 month after the operation, the mean cell density (CD), coefficient of variation(CV), and hexagonality of the corneal endothelial cells were examed and determined by Konan FA-3709P noncontact specular microscope, and the results were statistically compared. Main Outcome Measures The mean CD, CV, and hexagonality of the corneal endothelial cells. Results Compared with at pre-operation, the mean CD at 1 day, 3 day, 1 week, 1 month after surgery in the FLEx group and the FS-LASIK group were significantly decreased (all P<0.05). But there was no statistical significant between the two groups in CD at any time point (all P>0.05). Compared with at pre-operation, the mean CV at 1 day (P=0.007), 3 day (P=0.014), 1 week (P=0.003), 1 month (P=0.069) after surgery in the FLEx group were increased; the mean CV in the FLEx group were significantly increased at 1 day (P=0.039), 3 day (P=0.021), 1 week (P=0.001), 1 month (P=0.002) after surgery. There was no statistical significant between the two groups in CV at any time point(all P>0.05). Compared with at pre-operation, the hexagonalities of the corneal endothelial cells in the FLEx group were not significantly decreased at 1 day (P=0.091), 3 day (P=0.254) after surgery, were significantly decreased at 1 week (P=0.007) and 1 month (P=0.003) after surgery; the hexagonalities of the corneal endothelial cells in the FS-LASIK group were no statistical significant change at 1 day (P=0.619), 3 day (P=0.166), 1 month (P=0.135) after surgery, but were significantly decreased at 1 week after surgery (P=0.040).  There was no statistical significant between the two groups in the hexagonalities of the corneal endothelial at any time point. Conclusion Compared with  at pre-operation, the CD decreases slightly, and the CV slightly increases in FLEx group and FS-LASIK group at early postoperation. But the hexagonality of the corneal endothelial cells almost has no change in FLEx group and FS-LASIK group after surgery. There is no statistical significant between the two groups in CD, CV and hexagonality of the corneal endothelial cells.

Key words: femtosecond lenticule exraction, femtosecond laser in situ keratomileusis, corneal endothelium cell, specular microscope