Refractive results and intraocular scattering 5 years after high myopia correction: a comparison between SMILE and FS-LASIK surgeries

Abstract

Objective To compare the refractive results and scattering-related visual quality between small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (FS-LASIK) surgeries in 5 years after correction of high myopia and astigmatism. Methods A retrospective analysis was performed on 58 patients with high myopic who underwent corneal refractive correction surgery in our hospital from December 2011 to July 2013. The patients were divided into the SMILE group (n=30) and FS-LASIK group (n=28) according to their received surgical methods, only the left eyes being included for each patient. The preoperative and postoperative data at 3 and 6 months and 1 and 5 years were compared and analyzed. The observation indicators included uncorrected distant visual acuity (UDVA), corrected distance visual acuity (CDVA) and spherical equivalent (SE), and the parameters such as objective scattering Index (OSI), modulation transfer function cutoff frequency (MTFcutoff), Strehl ratio (SR), VA100%, VA20% and VA9% were examined using Optical Quality Analysis System (OQAS Ⅱ). Results During the follow-up of 5 years, the safety index was 1.136±0.099 in the SMILE group and 1.128±0.129 in the FS-LASIK group, and the efficacy index were 1.072±0.151 and 1.063±0.145 respectively, with no significant difference between the 2 groups (P>0.05). About 77% of treated eyes in the SMILE group and 71% in the FS-LASIK group obtained a postoperative UDVA of 1.0 or better. Predictability within ±0.50D accounted for 87% in the SMILE group and 75% in the FS-LASIK group. The SE of the SMILE group was (-7.22±0.91)D before surgery and (-0.12±0.38)D in 5 years after surgery, and those of the FS-LASIK group were (8.01±1.09)D and (-0.31±0.44)D respectively, indicating significant difference (P 0.05), while the differences in OSI and VA100% were significant (P < 0.05). Conclusion SMILE and FS-LASIK have similar efficacy, safety, predictability and stability in 5 years after high myopia correction, and SMILE has slightly less effect on intraocular scattering than FS-LASIK.

Keywords

• small incision lenticule extraction
• femtosecond laser-assisted lasik
• high myopia
• 5 years after operation
• visual quality
• scattering