| Background:Small incision lenticule extraction(SMILE),as the mainstream refractive surgery,has high safety and effectiveness for the correction of myopia and myopic astigmatism.To evaluate the therapeutic effect after surgery,it is not only satisfied with the recovery of vision,but more important is the improvement of visual quality,thus improving the quality of life of patients.However,some patients still have visual symptoms such as glare and poor vision at night.Factors that affect postoperative visual quality include preoperative pupil diameter(scotopic pupil),design of optical zone,age,and preoperative refractive state.Among them,scotopic pupil and optical zone play an important role in postoperative visual quality.However,the effect of the relationship between scotopic pupil and optical zone on postoperative visual quality of SMILE surgery is still controversial and needs further research.Purpose:To investigate the effects of the difference in the diameters of the scotopic pupil and the optical zone on the visual quality after Small incision lenticule extraction.Methods:The study was designed as a prospective randomized cohort study.Two-eye SMILE surgery was planned to be performed in the Fifth Affiliated Hospital of Guangzhou Medical University from February 2022 to December 2022.The eyes of the subjects who had scotopic pupils of 6.2 – 6.6mm(including 6.2 and 6.6 mm)before surgery were recruited and randomly divided into Group A(the group with scotopic pupils smaller than the diameter of optical zone,and the diameter of optical zone of both eyes = the diameter of scotopic pupils +0.2mm)and Group B(the group with scotopic pupils larger than the diameter of optical zone,and the diameter of optical zone of both eyes = the diameter of scotopic pupil-0.2 mm).Patients were followed up for three months after surgery.The uncorrected visual acuity(UCVA),best corrected visual acuity(BCVA)and subjective refraction were observed before surgery,one month and three months later,respectively.The higher-order aberrations(total higher-order aberrations,spherical aberration,coma aberration,and trefoil aberration of the cornea)of 6mm were measured using a Sirius anterior segment analyzer.The visual quality questionnaire was used to assess the patients’ visual phenomena(dryness,visual acuity fluctuation,glare,halo,fog,virtual shadow,night driving vision,fine operation,and reading difficulty)and satisfaction degree,and each was scored.Results:1.A total of 46 patients(92 eyes)were included in the study,23 cases(46 eyes)in group A and 23 cases(46 eyes)in group B.The preoperative optical diameters in group A and group B were 6.57±0.17 mm and 6.23±0.16 mm,respectively(P < 0.05).The mean preoperative CCT values were 540.22±24.54μm and 528.43±25.03μm,respectively(P < 0.05).Preoperative spherical power,cylindrical power,SE,UCVA,BCVA and scotopic pupil diameter between the two groups were not statistically significant.Before surgery,the differences in total optical path difference,total higher-order aberration,coma aberration,spherical aberration and point spread function in the corneal optical area when the pupil diameter was 6mm between the two groups were not significant(P > 0.05).There was no significant difference in the scores of each item in the subjective visual quality questionnaire between the two groups before operation.2.There was no significant difference in spherical power,cylindrical power,equivalent spherical lens,UCVA and BCVA between group A and group B at one month and three months after operation.3.In groups A and B,the total higher-order aberrations,coma aberration,spherical aberration and trefoil difference three months after surgery were significantly higher than those before surgery(P < 0.05),while the optical path difference and point spread function had no significant changes as compared with those before surgery(P > 0.05).One month after surgery,the total higher-order aberrations were 0.75±0.27 in group A and group B,and 0.86±0.26 in group B,showing a statistically significant difference(P=0.007).The spherical aberration in group A was 0.39±0.13,and that in group B was 0.50±0.16.The difference was significant between the two groups(P=0.001).There was no significant difference in the coma difference,trefoil difference between the two groups(P > 0.05).The optical path difference values in group A and group B were 1.09±0.37 and 1.11±0.36 respectively,and there was no significant difference between the two groups(P=0.276).The point spread function values in group A were 0.14±0.03,and those in group B were 0.15±0.04.,there was no significant difference between the two groups(P=0.352).The total higher-order aberrations in group A and group B three months after surgery were 0.75±0.27 and 0.86±0.22,respectively,P=0.006.The coma aberration values were 0.45±0.26 and 0.54±0.26,respectively,P=0.041.The spherical aberration of group A was 0.40±0.14,that of group B was 0.52±0.13 significantly higher than that of group A(P=0.000).The differences in trefoil difference between two groups were not significant(P > 0.05).There was no significant difference in trefoil difference between the two groups(P > 0.05).The optical path difference of group A was 1.05±0.35,and that of group B was 1.11±0.36.There was no significant difference between the two groups(P=0.303).The point spread function value of group A was 0.15±0.03,and that of group B was 0.15±0.04.,there was no significant difference between the two groups(P = 0.428).4.One month after surgery,the scores of glare in group A and group B of the subjective visual quality questionnaire were 1.71±0.78 and 2.91±1.68,respectively(P< 0.05).The night driving difficulty scores were 1.48±0.81 and 2.30±1.40,respectively(P < 0.05).The fine operation difficulty score was 1.76±0.90 in group A and 2.35±1.11 in group B,P=0.04.Three months after surgery,the halo scores of the group A and the group B were 1.70±0.70 and 2.41±1.22,respectively,P=0.044.The night driving difficulty score of the group A was 1.48±0.66,while that of the group B was 2.18±1.18,P=0.024.There was no significant difference in dryness,visual acuity fluctuation,glare,blurred vision,blurred vision,difficulty in fine operation,reading difficulty and visual satisfaction between the two groups(P > 0.05).Conclusions:1.Whether the optical zone is larger than or smaller than the scotopic pupil diameter,SMILE surgery is effective for the treatment of myopia and good uncorrected visual acuity can be obtained.2.When the scotopic pupil is larger than the diameter of the optical zone,the total higher-order aberrations,coma aberration and spherical aberration of the cornea after SMILE surgery in patients with low and moderate myopia are increased more significantly than those when the scotopic pupil is smaller than the diameter of the optical zone,but there is no difference in optical path difference and point spread function.3.When the scotopic pupil was larger than the diameter of the optical zone,the frequency of glare,halo and night driving difficulty of low and moderate myopia patients after SMILE surgery was higher than that when the scotopic pupil was smaller than the diameter of the optical zone,but there was no difference in overall visual satisfaction after surgery. |
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