| Objective:To investigate the changes of binocular stereopsis function after correction of ametropia by Femtosecond laser small incision lenticule extraction(SMILE).To clarify the characteristics of binocular stereoscopic vision after SMILE,and to establish stereoscopic vision adaptation strategies for clinical patients in the process of postoperative vision recovery.Methods:A total of 102 cases(204 eyes)of myopic and myopic astigmatism patients who underwent SMILE at the Eye and Optometry Center of the 940th Hospital of the PLA Joint Logistics Support Force from June 2020 to February 2021 and met the inclusion criteria were collected.The patients were divided into low myopia group(<-3.00 DS),moderate myopia group(-3.00DS～-6.00DS),and high myopia group(>-6.00DS)according to spherical equivalent,with 34 cases(68 eyes)in each group.Visual acuity,intraocular pressure(IOP),diopter,range of fusion,and stereoscopic acuity were examined before surgery,one day after surgery,one week after surgery,and one month after surgery in each group.All data were statistically analyzed.One-way Repeated-Measures analysis of variance and LSD-t test were used for analysis of the differences between indexes before and after the operation if the indexes within each group were normally distributed and the variance was homogeneous.If the indexes were non-normally distributed or the variance was not homogeneous,the non-parametric Friedman test was used to compare the difference between indexes before and after the operation.One-way Repeated-Measures analysis of variance and LSD-t test were used to analyze the differences between groups if indicators at each time point among the groups were normally distributed and the variance is homogeneous.Nonparametric Kruskal-Wallis test was performed to identify the differences between groups if the data was non-normally distributed or the variance was not homogeneous.Results:1.Visual acuity The uncorrected visual acuity of the three groups after surgery was significantly improved compared with before,and the uncorrected visual acuity of the three groups at each time point after surgery was better than before.The uncorrected visual acuity of the patients in the low myopia group,medium myopia group and high myopia group after surgery was significantly different from before(x~2=173.981,P<0.01;x~2=181.353,P<0.01;x~2=167.780,P<0.01).There was no significant difference among the three groups at each time point after surgery(P>0.05).2.Diopter The diopter of patients in the three groups significantly decreased at each time point after surgery compared with before,and SMILE had a significant effect on myopia correction.There were statistically significant differences in the diopter after surgery between the patients in the low myopia group,medium myopia group and high myopia group compared with before(x~2=136.471,P<0.01;x~2=140.299,P<0.01;x~2=134.416,P<0.01).There was no significant difference between the three groups at each time point after surgery(P>0.05).3.IOP The intraocular pressure of the patients in the three groups decreased after surgery compared with before,and there was no abnormal fluctuation in intraocular pressure at each time point after surgery.There were statistically significant differences in intraocular pressure after surgery between the patients in the low myopia group,medium myopia group and high myopia group compared with before(x~2=92.391,P<0.01;x~2=114.992,P<0.01;x~2=109.939,P<0.01).There was no significant difference between pairwise comparisons at each time point(P>0.05).There were significant differences in intraocular pressure between the three groups at one month after operation(P<0.01).4.Simultaneous perception The patients in the three groups had simultaneous perception before and after surgery,and the quantification levels were consistent,indicating that simultaneous perception was not affected by the degree of refractive error and early postoperative corneal trauma.5.Range of fusion The range of fusional convergence in the three groups after surgery was slightly lower than before.And the range of fusional convergence in the moderate myopia group declined more obvious than that of the low myopia group at one month after surgery.There were statistically significant differences in the range of fusional convergence after surgery between the low myopia group,medium myopia group and high myopia group compared with before(x~2=69.360,P<0.01;x~2=52.178,P<0.01;x~2=58.096,P<0.01).There was no significant difference in pairwise comparison at each time point after operation(P>0.05).There was only a statistically significant difference between low myopia group and moderate myopia group in the range of fusional convergence at one month after surgery when pairwise comparisons were made between the three groups(x~2=2.830,P<0.01).There was no significant difference between the different time points before and after surgery in the range of fusional separation(P>0.05).The changes of the total fusion range were consistent with the range of fusional convergence,and both of them decreased after surgery compared with before.6.Stereopsis The stereopsis of the patients in the three groups after surgery was lower than before,and the stereoscopic function of the patients in the three groups was significantly improved.There were statistically significant differences in the distance stereo acuity between the patients in the low myopia group,medium myopia group and high myopia group after surgery compared with before(x~2=83.185,P<0.01;x~2=74.330,P<0.01;x~2=79.716,P<0.01).There were statistically significant differences in near-stereoscopic visual acuity after surgery compared with before(x~2=77.374,P<0.01;x~2=74.160,P<0.01;x~2=87.361,P<0.01).There was no significant difference in pairwise comparison at each time point after surgery(P>0.05).Conclusion:SMILE can safely,effectively and stably correct refractive errors and improve uncorrected visual acuity.Simultaneous perception was not affected by early corneal trauma after SMILE,and did not change with time.The range of binocular fusion at one month after surgery was slightly lower than before,and the decline of the fusional convergence predominated and the fusional separation was not affected.The binocular stereopsis function at one month after surgery was significantly improved compared with before. |
