Clinical Research On The Change Of Refractive State After Muscle Surgery For Concomitant Exotropia

Objective: To compare the changes of refractive state and corneal morphology before and after exotropia correction surgery and their relationship with time.Methods: Prospective cohort studies.From June 2021 to October 2022,49 patients(60eyes)undergoing common exotropia correction surgery in the Department of Ophthalmology,Shengjing Hospital Affiliated to China Medical University were collected,and the follow-up time was 3 months.According to the surgical method,it was divided into 30 eyes in the lateral rectus recession group(LR group)and 30 eyes in the unilateral lateral rectus recession with medial rectus resection group(RR group).The best corrected visual acuity(BCVA),spherical power,cylinder power,equivalent spherical,corneal curvature,and corneal astigmatism value within 3 months after surgery were compared between the two groups,and the surgical induced astigmatism vector(SIA)at different time points in the two groups was compared with vector analysis.In this study,SPSS 23.0software was used to statistically analyze all data,and Wilcoxon rank sum test was used for different time comparisons in the same group,and Mann-Whitney U test was used for comparison between groups.Result:(1)There was no significant difference between the two types of exotropia surgery for the best corrected visual acuity after surgery compared with before surgery(P>0.05).(2)There were significant differences in the spherical power,cylinder power,equivalent spherical,flat corneal curvature,steep corneal curvature and corneal astigmatism in the lateral rectus recession group at 1 day and 1 week after surgery(P<0.05).(3)There were significant differences in the spherical power,cylinder power,equivalent spherical,flat corneal curvature,steep corneal curvature and corneal astigmatism in the unilateral lateral rectus recession with medial rectus resection group 1 day and 1 week after surgery(P<0.05),and there were statistically significant differences in cylinder power,flat corneal curvature and steep corneal curvature 1 month after surgery(P<0.05).(4)One day after surgery,the astigmatism value of the unilateral lateral rectus recession with medial rectus resection group was significantly higher than that in the lateral rectus recession group,and the difference was statistically significant(P<0.05);the postoperative diopters of both groups had a tendency to drift in the direction of myopia,but the unilateral lateral rectus recession with medial rectus resection group took longer to return to the preoperative state.(5)Vector analysis of the astigmatism changes of the two groups showed that there were significant differences in the surgical induction of astigmatism between the two groups at1 day,1 week and 1 month after surgery(P<0.05),and the changes in astigmatism caused by exotropia correction were mainly with-the-rule-astigmatism.(6)At 1 day and 1 week after surgery,there were significant differences in flat corneal curvature,steep corneal curvature and corneal astigmatism between the two groups(P<0.05),and this difference disappeared and stabilized at 1 month after surgery(P>0.05).Conclusion:(1)The refractive state drifts to myopia in the short term after exotropia correction,but returns to the preoperative state at 1-3 months after surgery.(2)Unilateral lateral rectus recession with medial rectus resection may cause greater astigmatism changes than lateral rectus recession,and it takes longer to return to the preoperative state.(3)The astigmatism caused by concomitant exotropia is mostly with-the-rule-astigmatism.(4)Exotropia correction will not affect the best corrected visual acuity of the surgical eye.