AIM:To observe the changes in corneal aberrations and the characteristics of visual quality after transepithelial photorefractive keratectomy(T-PRK)and femtosecond small incision lenticule extraction(SMILE)in the correction of low myopia.

METHODS: Prospective cohort study. A total of 32 cases(32 eyes)with low myopia who underwent T-PRK surgery and 45 cases(45 eyes)of SMILE surgery at Weifang Eye Hospital from April 2021 to April 2022 were selected. The uncorrected visual acuity(UCVA), best corrected visual acuity(BCVA), spherical equivalent(SE), corneal higher-order aberrations(HOAs)and objective visual quality were compared between the two groups.

RESULTS:All patients completed the surgery successfully without complications such as infection. At 3mo postoperatively, the safety index was 1.13±0.16 and 1.16±0.17(P=0.48)and the efficacy index was 1.10±0.20 and 1.15±0.18(P=0.27)in the T-PRK and SMILE groups, respectively. The percentage of UCVA(LogMAR)≤0 in the T-PRK and SMILE groups was 94% and 98%, respectively. The percentage of the residual SE within ±0.5D was 88% and 87% in the two groups, respectively. The HOAs and spherical aberration in both groups were significantly increased(P≤0.01), and the increase was not statistically significant between the two groups(P=0.31, 0.89). There was no significant change in horizontal coma, horizontal trefoil and vertical trefoil in both groups(P>0.05). The vertical coma in SMILE group was significantly increased(P<0.001), while there was no significant change in T-PRK group(P>0.05), and the increase was significantly greater in SMILE group than in T-PRK group(P<0.001). There was no significant difference in objective scattering index(OSI), modulation transfer function cut off frequency(MTF_{cut off}), Strehl ratio(SR), visual acuity(VA)100%, VA20% and VA9% between the two groups(P>0.05).

CONCLUSION:Both T-PRK and SMILE showed good safety, efficacy, and visual quality in correcting low myopia, while SMILE induced more vertical coma than T-PRK.