RESUMO
AIM: To compare the changes in corneal densitometry after small incision lenticule extraction(SMILE)and femtosecond laser in situ keratomileusis(FS-LASIK)and investigate the effect of corneal interface haze on vision after SMILE.METHODS: Prospective cohort study. A total of 93 patients(186 eyes)who were scheduled to undergo refractive surgery at the Ophthalmic Refractive Surgery Center of the Affiliated Hospital of Nantong University from May 2020 to October 2021 were included in the study, and there were 48 patients(96 eyes)in the SMILE group and 45 patients(90 eyes)in the FS-LASIK group. The changes in corneal densitometry, spherical equivalent(SE), and uncorrected visual acuity(UCVA)were observed and compared between the two groups before and at 1d, 1wk, 1, 3 and 6mo after surgery.RESULTS: The 93 patients all successfully completed the surgery, and there were no related complications during and after the surgery, and there were no lost cases. The UCVA of FS-LASIK group was 0.044±0.064 and -0.001±0.065 respectively at 1d and 1wk after surgery, which was better than that of SMILE group(0.102±0.077 and 0.023±0.064; all P<0.05). There was no statistical difference in the SE between the two groups at the postoperative follow-ups(P>0.05). The corneal densitometry values at 0-2 and 2-6 mm from corneal vertex and total corneal densitometry at 1d postoperatively in the FS-LASIK group were 18.0(17.5, 18.6), 16.2(15.6, 16.7)and 16.7(16.1, 17.3), which were lower than those of SMILE group [18.6(18.1, 19.3), 16.8(16.4, 17.4), 17.2(16.6, 17.8)](all P<0.05); The corneal densitometry values at 0-2 and 2-6 mm from corneal vertex and total corneal densitometry at 1wk postoperatively in the FS-LASIK group were 17.2(16.7, 17.6), 15.5(15.0, 15.9)and 15.9(15.3, 16.7), which were lower than those of SMILE group [17.6(17.1, 18.3), 16.0(15.6, 16.5), 16.6(15.9, 17.1)](all P<0.05).CONCLUSIONS: The transient interface haze after SMILE is responsible for the early higher corneal densitometry than FS-LASIK. The presence of interface haze is probably a factor for the quality of vision.
RESUMO
AIM: To compare the efficacy of and without small incision lenticule extraction(SMILE)with cyclotorsion compensation for astigmatism correction.METHODS: PubMed, Web of Science, EMBASE, Cochrane and CNKI, VIP, CBM, and Wan Fang Data were searched for clinically controlled studies from January 2010 to August 2022, including an experimental group with cyclotorsion compensation during SMILE and a control group without cyclotorsion compensation during SMILE. After literature screening, quality evaluation, and data extraction by two researchers independently, the Meta-analysis of uncorrected distance visual acuity(UDVA), residual astigmatism, vector analysis indicators for measuring the astigmatism correction including absolute value of angle of error(|AE|)and magnitude error(ME), and post-operative total higher order aberrations, spherical aberration and coma was carried out with Stata 16.0 software.RESULTS: Seven studies with a total of 846 eyes(442 in the experimental group, 404 in the control group)were finally included. The Meta-analysis showed that there were significant differences in the percentage of eyes with residual astigmatism ≥1.00D(OR=0.17, 95%CI: 0.06～0.49, P<0.01), |AE|(WMD=-1.56, 95%CI: -2.68～-0.45, P<0.01), the coma(WMD=0.06, 95%CI: -0.08～-0.04, P<0.01), and the total higher order aberrations(WMD=-0.04, 95%CI: -0.06～-0.02, P<0.01). However, there were no differences in the postoperative UDVA(WMD=0.00, 95%CI: -0.02～0.01, P=0.54), residual astigmatism(WMD=0.08, 95%CI: -0.02～0.18, P=0.10), ME(WMD=-0.01, 95%CI: -0.14～0.12, P=0.85), and the spherical aberration(WMD=0.03, 95%CI: -0.07～0.13, P=0.52).CONCLUSION: Cyclotorsion compensation in SMILE can reduce the angular error caused by eye rotation during astigmatism correction. It also decreases postoperative residual astigmatism. Overall, the SMILE with cyclotorsion compensation is superior in clinical efficacy of the precise correction of astigmatism.