Abstract
Purpose :
To compare the visual outcomes and complications of femtosecond laser in situ keratomileusis (FS-LASIK) and femtosecond laser sub-Bowman keratomileusis (FSBK) with those of surface treatment by epithelial laser in situ keratomileusis (Epi-LASIK) for the correction of low-to-moderate myopia.
Methods :
This retrospective review comprised all eyes of FS-LASIK (n= 242), FSBK (n= 62) and Epi-LASIK (n=183) performed between Jan 2008 and Dec 2013. Preoperative and postoperative assessment included Snellen uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction, and complications. Patients were followed for at least 3 months.
Results :
The median age at surgery was 29.4 years (FS-LASIK), 28 years (FSBK) and 31.6 years (P <0.01). The median preoperative values were: central corneal thickness, 577±36 um (FSBK), 566±35 (FSBK) and 550±35 (Epi-LASIK) (P < 0.001); spherical equivalent, -3.75D (FS-LASIK), -4.0D (FSBK) and -3.75D (Epi-LASIK) (P <0.001); mean keratometry, 43.2D (FS-LASIK), 42.7D (FSBK) and 42.8D (Epi-LASIK); and BCVA of 20/20, 91.7% (FS-LASIK), 87.3% (FSBK) and 84.4% (Epi-LASIK) (P = 0.06). Flap thickness was: 120.2±4.6 (FS-LASIK), 101±3.2 (FSBK) and 50.8±6.2 (Epi-LASIK) (P <0.001). Visual recovery was slower after Epi- LASIK. A successful refractive surgery (most recent postoperative UCVA of 20/40 or better) was acquired in 95% (FS-LASIK), 96.8% (FSBK) and 92.3% (Epi-LASIK) of eyes. Moderate myopia (-2.5D to -6D) (P = 0.003) and the use of mitomycin C (P = 0.0003) were factors associated with success. Gaining of 1 line or more was attained in 95.0% (FS-LASIK), 98.3% (FSBK) and 93.9% (Epi-LASIK) of eyes (P = 0.11). Loss of 1 line occurred in one eye after Epi-LASIK.
Conclusions :
Both thin-flap LASIK (FSBK) and conventional thick-flap LASIK (FS-LASIK) are safe and effective procedures to correct low-to-moderate myopia. Both femtosecond flap procedures provided better outcomes than surface ablation (Epi-LASIK) procedure. In eyes requiring deeper ablation, FSBK surgery provided slightly higher success rate.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.