Relations Of Subjective Visual Quality Of Patients Undergoing SMILE,Fs-LASIK And T-PRK Surgery With Corneal Aberrations And Confocal Microscopy Results

OBJECTIVETo compare the corneal aberrations and post-operational nerve regeneration of patients undergoing SMILE,Fs-LASIK and T-PRK surgery,and study the relations of subjective visual quality with corneal aberrations and nerve fiber regeneration.METHODSA total of 55 patients(109 eyes)who choose refractive surgery for refractive error correction in Peking Union Medical College Hospital are included in this research.Based on patients' preference and doctor' s advice,they are divided into 3 surgical groups:35 patients(69 eyes)in SMILE,9 patients(18 eyes)in Fs-LASIK and 11 patients(22 eyes)in T-PRK.The spherical equivalent(SE)of SMILE,Fs-LASIK and T-PRK groups before surgery range from-2.00D to-8.50D,-2.25D to-8.00D and-3.50D to-6.00D respectively.The average SE of the three groups are-5.28D±1.55D,-5.81D±2.12D and-4.54D±0.71D respectively.Patients undergo all routine pre-operational examinations.Besides,Corneal wavefront analysis and confocal microscopy examination are conducted on first visit and 7 days,30 days and 90 days after surgery.Patients are asked to fill in subjective visual quality questionnaire at each visit.ACCMetrics V.2 is used to analyze nerve fibers in confocal microscopy photos.The student' s t-test,one-way analysis of variance and Pearson correlation study are adopted for data analysis on SPSS 22.0 software.RESULTS1.High order aberrations increased dramatically after surgery.Coma,spherical aberrations and secondary astigmatism gains most.SMILE group has the lowest total high order aberration 7 days after surgery(1.808 vs 2.410 vs 2.122,p<0.05),but shows no statistical difference 30 days and 90 days after surgery.2.Fs-LASIK group has the highest coma and spherical aberration 7 days,30 days and 90 days after surgery,while T-PRK group has the highest secondary trefoil aberration and secondary coma at the last 2 visits.3.The nerve fiber density and branch density of SMILE group are statistically higher than the other 2 groups at all post-operational visits.3 groups show no difference on nerve fiber width.4.Patients suffer from the worst subjective visual quality 7 days after surgery,but get it improved to pre-operational level gradually afterwards.Fs-LASIK group suffers most from halos and false shadowing 7 days after surgery.But 3 groups show no difference of all visual symptoms 30 days and 90 days after surgery.5.The overall subjective visual quality of 7 days after surgery shows strong positive correlation with nerve fiber density(CNFD)and nerve fiber length(CNFL).There shows negative correlation of glare score with coma,flash score with coma and spherical aberration,halo score with coma and secondary astigmatism,false shadowing score with secondary astigmatism,fine operation score with secondary astigmatism and reading score with spherical aberration and secondary astigmatism 7 days after surgery.But there exists no statistically significant correlation of subjective visual quality with either nerve fiber parameters or corneal aberrations 30 days and 90 days after surgery.CONCLUSIONSSMILE group shows better corneal nerve fiber and high order aberration outcome than Fs-LASIK and T-PRK group.Better preservation of corneal nerve fiber and lower coma,spherical aberration and secondary astigmatism at early post-operational period are positively correlated with subjective visual quality.3 surgical groups show no difference of visual quality 30 days and 90 days after surgery.