Results Of Small Incision Lenticule Extraction:Correction Of Myopia Correction And Visual Quality

Objective To evaluate the efficacy, predictability, stability, safety and complications in myopic patients after small incision lenticule extraction(SMILE) using VisualMax femtosecond(Zeiss). Analyze the changes in high order aberrations(HOAs) and the contrast sensitivity in myopic patients after the surgery, and then compare the relationship between the preoperative spherical equivalent refraction(SE) and the aberrations, in order to evaluate the postoperative visual quality.Methods In this retrospective clinical study, seventy-six patients with myopia underwent small incision lenticule extraction using the VisualMax femtosecond laser. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), refraction, high order aberrations(HOAs), contrast Sensitivity, intraocular pressure (IOP) and clinical complications were evaluated before and after the implantation. The follow-up was3months. Postoperative examinations were performed at1day,1week,1month,3months after the surgery.Results3months After the surgery, UCVA improved in76eyes(P<0.05). UCVA of20/20or better was observed in76eyes (100%). Postoperative UCVA was equal to or better than preoperative BCVA in60eyes (79.02%),17eyes (22.23%) lost one line in Postoperative UCVA than preoperative BCVA. Mean spherical equivalent (SE) decreased significantly from-4.235±1.448D to-0.194±0.603D (P<0.05). There is no significant different among the SEs in lday.1week.1month.3months after the surgery (P>0.05). For5-mm corneal diameter, significant increases in corneal root-mean-square (RMS) high order aberration (HOA), RMS spherical aberration (SA) were observed1months after surgery (P<0.05).3months after surgery, RMS SA also increased than1months after surgery (P<0.05). For3-mm corneal diameter,3months after surgery, RMS SA also increased than1months after surgery (P<0.05).Significant correlations were found between preoperative RMS SE and RMS Total HOA, or RMS coma aberration, or RMS trefoil aberration. Under the space frequency in5,10,15,20,25,30cyc/deg, modulation transfer function (MTF)1day after surgery increased significantly than preoperation (P=0.000), and then decreased1week after surgery (P<0.05). At3,6,12,18cpd, contrast sensitivity (GS) slightly increased along the time. There are no serious intraoperative and postoperative complications occurred in this study.Conclusions After3-month follow-up, SMILE is proved to be an effective, predictable, and safe procedure for the correction of myopia. However, the increase HOAs are found, specially the SA. Larger sample size and longer follow-up with a larger cohort is necessary to confirm these conclusions.