Macular and retinal nerve fiber layer thickness changes after small-incision lenticule extraction and femto-LASIK

Abstract

Introduction Femtosecond laser flap creation exerts less intraocular pressure (IOP) fluctuation but requires more procedural time compared with microkeratome flap creation. This IOP elevation during suction may affect the macular and retinal nerve fiber layer thickness that can be assessed with optical coherence tomography. Purpose The aim of this study was to compare the influence of the transient elevation of IOP during suction on the macular and retinal nerve fiber layer thickness after small-incision lenticule extraction (SMILE) and femtosecond laser-assisted in-situ keratomileusis (femto-LASIK). Patients and methods A total of 80 and 75 eyes that received SMILE and femto-LASIK procedures for myopia and myopic astigmatism, respectively, were enrolled in this study. Spectral-domain optical coherence tomography was used to measure macular and peripapillary retinal nerve fiber layer thickness preoperatively, at 1 week, and 1, 3, and 6 months postoperatively. Results The study included 155 eyes. In both the SMILE group and the femto-LASIK group, the mean foveal, parafoveal, and perifoveal retinal thickness did not change significantly from the preoperative to any postoperative timepoint (P > 0.05). The mean foveal retinal thickness was significantly greater in the femto-LASIK group than in the SMILE group (P 0.05). The differences in the retinal nerve fiber layer between the SMILE group and the femto-LASIK group were not statistically significant at any follow-up visit (P > 0.05). Conclusion Both SMILE and femto-LASIK procedures had no significant effects on the macular and retinal nerve fiber layer thickness postoperatively.