Corneal Nerve Repair After Different Laser Keratomileusis In Patients With High Myopia And Its Correlation With Optical Density And Ocular Surface Disease Index (OSDI)

Purpose: to investigate the repair of corneal nerve fibers at different time after small incision lenticule extraction(SMILE),femtosecond laser-assisted in-situ keratomileusis(FS-LASIK)and excimer laser in situ keratomileusis(LASEK)in patients with high myopia and their correlation with corneal optical density and ocular surface disease index(OSDI).Methods: 55 patients(110eyes)with high myopia who underwent corneal refractive surgery in the Affiliated Hospital of Qingdao University of Shandong Province from June2018 to December 2020 were divided into SMILE group(12 males and 10 females,44eyes)、FS-LASIK group(10 males and 8 females,36 eyes)and LASEK group(9 males,6females,30 eyes)in.Laser confocal microscopy,Pentacam three-dimensional anterior segment analysis and ocular surface disease index(OSDI)questionnaire were performed in each group at 1m,3m,6m and 12 m after operation.the data were statistically analyzed by SPSS 22.0 software.Results: 1.At 1m postoperatively,the central CNFD,CNFL and CTBD of SMILE and FS-LASIK group were significantly better than those of LASEK group,with statistical significance(P< 0.05).The CNBD of SMILE operation was significantly better than that of the other two methods(P< 0.05).The central CNFD,CNBD,CNFL of 3m after operation was significantly better than that of the other two methods,while the CNFW of LASEK operation was significantly better than that of other operations(P< 0.05).After 6m operation,the central CNFD,CNBD and CNFL of SMILE operation were better than those of the other two methods,and there was significant difference(P< 0.05).There was no significant difference in the parameters of central corneal nerve among the three methods at 12 m after operation.2.There was no statistically significant difference in the corneal optical density of 1m and 6m among the three groups after surgery(P>0.05).At 3m after operation,the optical density of LASEK was significantly lower than that of SMILE and FS-LASIK in the range of 0～6 mm,6～12 mm and total diameter(P<0.05).12 m after surgery,the corneal optical density of SMILE surgery was significantly lower than that of the other two surgery methods in the range of 0～6mm,6～12mm and total diameter(P<0.05),while the difference between the other two surgery methods was not statistically significant.The optical density within each diameter range of SMILE showed a gradually decreasing trend after operation,and reached the lowest at 12 m after operation.However,the changes of optical density within each diameter range after LASEK decreased first and then increased.The predisposing factors of postoperative 1m SMILE operation were significantly higher than those of the other two groups,and the difference was statistically significant(P< 0.05).There was no significant difference in the parameters of OSDI between 3m,6m and 12 m after operation.4.The central corneal optical density(diameter range 0～6mm)at 1 m after operation was negatively correlated with CNBD and CNFL,and the correlation coefficients were-0.448 and-0.4474,respectively,while CNFD and CNBD at 3 m after operation were positively correlated with central optical density with correlation coefficients of0.413,0.383,There was no significant correlation between central corneal optical density at 6 m and 12 m after operation and the parameters of central corneal nerve.5.There was a significant positive correlation between OSDI score and central CNFD at 1 m after operation,and the correlation coefficient was 0.743.There was no significant correlation between OSDI score and nerve fiber parameters at 3m,6m and 12 m after operation.Conclusion:In the early and middle stages of the operation,the central corneal nerve repair of SMILE group had a significant advantage.In the long term after the operation,there was no significant difference in the nerve repair of the three methods.At the early stage after the operation,the corneal transparency of the LASEK method was relatively good,but the long term after the operation,the corneal transparency of the SMILE method was the best.Early postoperative ocular surface sensitivity may be related to the degree of corneal nerve repair.