Five-year results of small incision lenticule extraction (SMILE) and femtosecond laser LASIK (FS-LASIK) for myopia.

Purpose: To compare visual outcomes and aberration outcomes in small incision lenticule extraction (SMILE) versus femtosecond laser LASIK (FS-LASIK).

Methods: This prospective, comparative, nonrandomized clinical study included 68 eyes of 37 patients receiving SMILE and 55 eyes of 30 patients receiving FS-LASIK between December 2011 and January 2013 at the Fudan University Eye and ENT Hospital (Shanghai, People's Republic of China). Patients were followed up at 3, 6 months and 5 years after surgery. Main outcome measurements included uncorrected (UDVA) and corrected (CDVA) distance visual acuity, manifest refraction, central corneal thickness (CCT), total corneal refractive power (TCRP) and wavefront aberrations.

Results: About 98% (49/50) of treated eyes in the SMILE group and 95% (39/41) in the FS-LASIK group had a postoperative logMAR UDVA of 0 or better. Spherical equivalent (SE) after 5 years was -0.01 ± 0.35 D in the SMILE group and -0.23 ± 0.41 D in the FS-LASIK group. A regression of -0.02 ± 0.39 D in the SMILE group and -0.12 ± 0.32 D in the FS-LASIK group was observed between 6 months and 5 years postoperative time-points. TCRP increased by 0.39 ± 0.38 D in the SMILE group and 0.45 ± 0.49 D in the FS-LASIK group between 6-month and 5-year time-points. However, no statistically significant difference was found between the SMILE and FS-LASIK groups in terms of ∆SE, ∆CCT and ∆TCRP between 6 months and 5 years postoperative time-points.

Conclusion: Myopic regression was observed in terms of TCRP but not in subjective refraction. No statistically significant difference in stability was found between SMILE and FS-LASIK.