Comparative Analysis Of Early And Mid-term Visual Quality After Three Types Of Corneal Refractive Surgery

Objectives:To compare the changes in subjective and objective visual quality after LASEK,FS-LASIK and SMILE surgeries to correct myopic astigmatism,and to assess the objective visual quality of the three surgeries at the same degree of myopia.Method:230 patients(460 eyes)with simple myopia and myopic astigmatism who underwent corneal refractive surgery at the Refractive Eye Centre of the Second People’s Hospital of Yunnan Province from January 2020 to September 2020 were collected,and 57 cases(114 eyes)of LASEK,85 cases(170 eyes)of FS-LASIK,and 88cases(170 eyes)of SMILE were performed according to the patients’self-selected surgical procedures,provided that the indications for surgery were met.The patients were divided into mild,moderate and high myopia groups according to the equivalent spherical lens degree.Subjective evaluation indexes included:naked eye visual acuity(UCVA),Quality of Life Inventory for Refractive Correctors(QIRC);objective evaluation was performed using the two-channel visual quality analysis system(OQASII),with objective scatter index(OSI),modulation transfer function cut off frequency(MTF cut off),and Strehl ratio(SR)selected as indexes.Data were collected preoperatively,1 month postoperatively and 6 months postoperatively,and the data were statistically analysed using SPSS25.0 statistical software.Results:1.Pre-operative baseline data:There were no statistical differences in gender(x~2=1.744),age(F=0.778)and dark chamber pupil diameter(F=0.100)between the LASEK,FS-LASIK and SMILE groups.2.LASEK,FS-LASIK and SMILE all improved the patients’naked eye visual acuity,and the recovery of naked eye visual acuity was faster and more stable with SMILE.UCVA was greater at 6 months postoperatively than at 1 month postoperatively for LASEK and FS-LASIK,and greater at 1 month postoperatively than preoperatively(P<0.001).UCVA improved at 1 month postoperatively compared to preoperatively for SMILE(P<0.001)and was not statistically different from 6 months postoperatively.3.LASEK,FS-LASIK and SMILE all improved patients’quality of life,but there was no difference in QIRC scores between the three surgical procedures,score increased at 6 months post-operative compared to 1 month post-operative(P=0.001).There were no statistically significant differences between LASEK,FS-LASIK and SMILE preoperatively,1 month postoperatively and 6 months postoperatively,nor were there statistically significant differences between men and women.4.The quality of vision decreased at 1 month after surgery for LASEK,FS-LASIK and SMILE compared to the preoperative period.OSI increased in the LASEK mild myopia group in January compared to preoperative and postoperative months(P=0.008);OSI was greater in the moderate myopia group in January compared to preoperative and postoperative months(P<0.001);SR was less than preoperative and postoperative months(P=0.021).The changes in OSI,MTF cut off and SR at 1 month postoperatively and 6 months postoperatively were not statistically different;OSI at 1 month postoperatively was greater than preoperatively in the moderate myopia group(P<0.001);OSI at 1 month postoperatively was greater than preoperatively and 6months postoperatively in the high myopia group(P<0.001),and MTF cut off at 1month postoperatively was less than preoperatively and 6 months postoperatively(P<0.001).The OSI at 1 month postoperatively was greater than preoperatively in the SMILE mild and moderate myopia group(P=0.002,P=0.023);the MTF cut off at 1month postoperatively was less than preoperatively and 6 months postoperatively in the high myopia group(P=0.001).5.In mild myopia with LASEK,FS-LASIK and SMILE,there was no statistical difference in OSI,MTF cut off and SR between the three surgical procedures before,1month after and 6 months after surgery.For moderate myopia with LASEK,FS-LASIK and SMILE,the OSI of SMILE surgery at 1 month postoperatively was less than that of LASEK surgery(P=0.017)and the SR was greater than that of LASEK surgery(P=0.005).For both FS-LASIK and SMILE surgery for high myopia,the SMILE surgery OSI values at 1 month postoperatively were less than FS-LASIK and the MTF cut off was greater than FS-LASIK surgery(P=0.048).There was no statistical difference in OSI,MTF cut off,and SR between the two procedures preoperatively and at 6 months postoperatively.Conclusion:1.Subjective visual quality improved and quality of life improved in patients after LASEK,FS-LASIK and SMILE.However,the surgical approachs does not affect the quality of vision.Objective visual quality dropped in the early postoperative period and gradually recovered with time,with better visual quality at the sixth month post-operation than at the first month after operation.2.There were some differences in the effects of different diopters on visual quality,with no difference in visual quality at any time point between LASEK,FS-LASIK and SMILE for mild myopia.SMILE was better than LASEK for moderate myopia at the first month after operation.SMILE was better than FS-LASIK for high myopia at the first month after surgery.And there was no statistical difference between the surgical modalities at the sixth month after operation.