Clinical observation and countermeasure of corneal flap of LASIK flap creation with a femtosecond laser in 2402 patients

Abstract

Objective To observe the clinical effect of the cornea flap created with a femtosecond laser and analyze the treatment methods of undesirable flap.Methods A total of 2402 myopic patients (4697 eyes) were treated with LASIK using the Technolas 217z100 laser system.According to preoperative design,255 patients (479 eyes) had an intended flap thickness of 90μ m,2091 (4138eyes) were 110μ m and 56 patients (80 eyes) were 140 μ m.The analysis of the flap thickness that measured by optical coherence tomography (OCT) at one week after surgery was determined.Results The measured flap thickness:The 90μ m flap group had a mean flap thickness of 90.54+ 6.06μ m(82～101μ m),the 110μ m flap group had a mean flap thickness of 109.79+ 7.62μ m (103～116μ m),while for the 140μ m group the mean flap thickness was 138.85± 5.68μ m (129～147μ m).The difference between the measured flap thickness and intended flap thickness was not statistically significant (P ＞0.01).In the early course of making cornea flap,five kinds of undesirable phenomenon of corneal flap were:Corneal stromal surface center of large particles,Corneal stromal surface of stripe,Corneal stromal surface of adhesive strip,Corneal stromal surface of center adhesive,Femtosecond laser cutting corneal conjunctiva junction bubbles.To adjust them in time during the operation,they were given a series of processing method.Conclusions The Ziemer FEMTO LDV laser created LASIK flaps have good predictability and safety.To a certain extent,LASIK with the FEMTO LDV femtosecond laser can restrain the increase of aberrations,and improve the contrast sensitivity and visual function. Key words: Femtosecond laser; LASIK; Complication