Aim: We analysed one-year refractive results and the incidence of complications in patients with correction of low-to-high myopia or myopic astigmatism by femtosecond laser in situ keratomileusis (FS-LASIK) using femtosecond laser LenSx® (Alcon, Fort Worth, Texas, USA) a excimer laser Excimer Amaris 500 (Schwind eye-tech-solutions GmbH and Co KG, Kleinostheim, Germany).
Methods: To the retrospective study were included 171 eyes of 87 patients (38 men, 49 women) who underwent correction of myopia and myopic astigmatism by FS-LASIK in the outpatient Department of Ophthalmology, University Hospital in Hradec Králové between 2013-2017. We assessed uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA), subjective refraction, central corneal thickness (CCT) in the thinnest point, patient’s satisfaction and the incidence of complications in the one-year follow-up period.
Results: At the time of laser procedure the mean patient‘s age was 29,26 ± 6,47 years (range 18 to 46 years). In 21 eyes was corrected myopia (range -6,5 to -2,5 D sph) and in 150 eyes myopic astigmatism (range -8,75 to -0,25 D sph and -3,0 to -0,25 D cyl). The mean preoperative UCVA 0,06 ± 0,08 (range 0,02 to 0,8) got better to 1,12 ± 0,17 (range 0,8 to 1,5) at the end of follow-up period. There wasn’t statistically significant change in BCVA between preoperative and postoperative values. Preoperative mean value of subjective refraction was -4,14 ± 1,43 D sph (range -8,5 to -1 D sph) and -0,57 ± 0,58 D cyl (range -3 to 0 D cyl) and after 12 months -0,02 ± 0,16 D sph (range -0,1 to 0,75 D sph) and -0,01 ± 0,1 D cyl (range -0,5 to 0,5 D cyl). The initial mean CCT was 554,76 ± 30,07 μm (range 485 to 660 μm), after 6 months 494,06 ± 34,99 μm (range 421 to 594 μm) and after 12 months 492,92 ± 34,55 μm (range 411 to 592 μm). We observed peroperative complications in 3 eyes. The suction loss of femtosecond laser occurred during flap creation due to sudden eye movement. Postoperatively in one case we enrolled flap pucker first postoperative day. In other case flap dislocation occurred after abdonimal surgery under general anesthesia which was performed 3 months after refractive procedure and we had to indicate flap reposition. The mean grade of patient’s satisfaction was at the end of follow-up period 1,04. The most often complaints were the sensation of dry eye (10 patients) and blurry vision during computer working, inadequate lighting and fatique (6 pacients).
Conclusions: According to our experience correction of low-to-high myopia or myopic astigmatism by using FS-LASIK is an effective, relatively safe and predictable method. The basic assumption of good postoperative results and patient’s satisfaction is thorough and comprehensive preoperative examination with respect to indication criteria.
Effect of femtosecond and microkeratome flaps creation on the cornea biomechanics during laser in situ keratomileusis: one year follow-up
