Abstract:

Objective    To discuss the characteristics of corneal flap made by Ziemer FEMTO LDV femtosecond laser. Methods    50 myopic patients ( 100 eyes) desired for refractive surgery were enrolled in this study. Corneal flaps were all made by Ziemer FEMTO LDV femtosecond laser. Pre-operative examinations included diopter, corneal topography, and corneal thickness etc. Anterior segment optical coherence tomography was used to measure corneal parameters on the horizontal direction at one week post-operatively. Then the centrality, stability and uniformity of corneal flaps were analyzed. Results   The central position of corneal flaps distanced the central position of cornea about (0.29±0.20)mm. Horizontal diameter of corneal flaps presupposed differed with the actual in the range of (1.04±0.49)mm. Average thickness of corneal flaps was (119.29±2.23)μm. Horizontal average thickness of corneal flaps made differences at the bitamporal side 1.5mm, 2.5mm, 3.5mm［(118.94±2.34)μm, (119.14±2.65)μm, (119.53±2.77)μm, respectively］ and the nasal side 1.5mm, 2.5mm, 3.5mm［(118.98±2.55)μm, (119.38±2.47)μm, (119.77±2.64)μm, respectively］ around the central position of corneal flaps. Conclusion    In LASIK, corneal flaps made by Ziemer FEMTO LDV femtosecond laser are in the neutral well, and there are no significant correlation between position offset and astigmatism. Corneal flaps are steady, uniform and predictable.

Key words: Femtosecond laser, Anterior segment OCT, Corneal flap, LASIK