The Changes Of Posterior Corneal Higher-order Aberrations In Myopia Eyes After Four Mainstream Refractive Surgeries

Purpose Compare the change of posterior corneal higher-order aberrations(HOAs)of myopic eyes after four refractive surgeries including laser in situ keratomileusis(LASIK),femtosecond laser-assisted laser in situ keratomileusis(FS-LASIK),wavefront-guided LASIK with iris registration(WF-LASIK),and small incision lenticule extraction(SMILE).Methods A total of 242 subjects(46 subjects underwent LASIK,38 subjects underwent FS-LASIK,68 subjects underwent WF-LASIK,and 90 subjects underwent SMILE)were involved.HOA of each patient's right eye were measured with Pentacam device preoperatively and 6 months after surgery.The aberrations were described as Zernike polynomials,and analysis focused on total HOAs,spherical aberration(SA),coma,horizontal coma,and vertical coma over 6 mm diameter central corneal zone.Results In LASIK group,pre-and postoperative total HOA,SA and horizontal coma were not statistically significantly different,but postoperative coma and vertical coma were(P values were 0.049 and < 0.001,respectively).In FS-and WF-LASIK groups,significant differences were found in the total HOA,SA and coma,no differences were found in the horizontal coma and vertical coma.In addition,all HOAs were found significantly differences between pre-and postoperative SMILE procedure(P values were < 0.001).The result showed that SMILE induced significantly negative shift in horizontal coma compared with FS-LASIK and WF-LASIK(P values were 0.006 and<0.001,respectively).Meanwhile,SMILE group also had a significant increase in vertical coma compared with FS-LASIK and WF-LASIK(P values were < 0.001).InLASIK and the other groups,induced total HOA,SA,coma,horizontal coma and vertical coma were all comparable(P values were > 0.05).Conclusion SMILE induced more horizontal coma and vertical coma compared with FS-LASK and WF-LASIK,indicating that the centration of SMILE procedure is probably less precise.