Effects of SMILE and FS-LASIK on early postoperative corneal higher order aberrations in patients with high myopia

AIM: To study the effects of small-incision lenticule extraction(SMILE)and femtosecond laser-assisted excimer laser in situ keratomileusis(FS-LASIK)on early postoperative corneal higher order aberrations(HOAs)and visual quality in patients with high myopia. METHODS:Totally 102 patients(204 eyes)with high myopia who underwent corneal refractive surgery between August 2018 and August 2020 in the hospital were selected as study subjects for the prospective study, and they were randomly divided into SMILE group(51 cases, 102 eyes)and FS-LASIK group(51 cases, 102 eyes). The postoperative visual acuity, corneal HOAs and objective visual quality were compared between the two groups, and the correlation between corneal HOAs and objective visual quality was analyzed. RESULTS: At 1mo after surgery, the spherical equivalent degrees in SMILE group and FS-LASIK group were significantly reduced(P0.05). The corneal HOAs in the two groups were significantly increased(P<0.05), and the overall spherical aberration(SA), trefoil and higher HOAs in SMILE group were lower than those in FS-LASIK group(all P<0.05). The objective scattering index(OSI)was significantly increased in the two groups while the MTF cutoff frequency(MTFcutoff), Strehl Ratio(SR)and contrast visual acuity(VA100%, VA20%, VA9%)were significantly decreased(all P<0.05). The OSI of SMILE group was lower than that of FS-LASIK group while MTFcutoff and VA9% were higher than those of FS-LASIK group(all P<0.05). The corneal HOAs in patients with high myopia were negatively correlated with MTFcutoff and were positively correlated with OSI(P