Clinical Study On Changes Of Refraction And Corneal Topography In Horizontal Strabismus Surgery

Objectives:To investigate the effects of different surgical methods of horizontal strabismus surgery on the shifts of refraction and corneal topography at different postoperative periods.preliminary research of the mechanism was discussed.It would provide a significant guidance for the further improvement of the surgical design of horizontal strabismus surgery and postoperative optometry.Methods:It was a method of prospective study.Collect the materials of patients who had undergone strabismus surgery in our hospital from January 2018 to December 2018 and insisted on follow-up.there were 56 cases(79 eyes),25 males(36 eyes),31 females(43 eyes),aged 6 to 30 years old(average age 11.6 years old).With no people having a history of systemic diseases or other eye problems,they were all the first time to perform strabismus surgery.All the patients were able to cooperate with cycloplegic refraction and computer-assisted corneal topography examination.According to the operation methods,they were divided into four groups.Compare diopter of spherical equivalent,spherical,cylindrical and axis of astigmatism between one day preoperatively and one week,one month and three months postoperatively.Mean curvature of the cornea at four meridians(nasal,temporal,upper and lower)which was 1.5mm and 3mm from the corneal apex was also made comparision between one day before surgery and one week,one month and three months after surgery.All data were incorporated into SPSS17 statistical software for analysis.Results:1.The changes in diopter of spherical equivalentThere was a signifcant difference in group A and group B in the diopter of spherical equivalent one week after operation compared with that before operation,and it was statistically significant(P<0.05).While there was no significant differennce in one month and three months after surgery compared with that before surgery(P>0.05).Group C and group D had significant differences in the diopter of spherical equivalent one week and one month after operation(P<0.05),but no significant difference in that three months after operation(P>0.05).2.The changes in diopter of sphericalIn group A and group B,there was no signifcant difference between preoperative and postoperative,and it was statistically insignifcant(P>0.05).In group C and group D,there was a significant difference in the diopter of spherical between one day before surgery and one week after surgery(P<0.05),but there was no significant difference in the diopter of spherical between one day preoperatively and one month and three months postoperatively(P>0.05).3.The changes in diopter of cylindricalIn group A and group B,the changes one week after operation were significantly different(P<0.05),while the changes one month and three months after operation were of no significant difference(P>0.05).There was a signifcant difference in group C and group D in the diopter of cylindrical one week after surgery compared with that before surgery,and it was statistically significant(P<0.05),but there was no significant differennce in one month and three months after surgery compared with that before surgery(P>0.05).4.The changes in axis of astigmatismThere was an increase in the proportion of astigmatic eyes in one week and one month after surgery compared with before surgery,and the difference was statistically signifcant(P<0.05),in which the increase was mainly astigmatism with the rule.There was no statistically signifcant difference in the ratio of astigmatism between three months after operation and one day before operation(P>0.05).5.The changes in curvature of corneal topographyIn all of these groups,the changes in curvature of corneal topography postoperatively were of no significant difference(P>0.05).Conclusions:1.The changes in diopter of spherical equivalent and cylinderical were obvious after operation,and the changes in diopter of spherical equivalent were mainly caused by the changes in diopter of cylinderical.2.The postoperative shifts in axis of astigmatism were mainly the increase of astigmatism with the rule.3.There was no significant change in corneal curvature after horizontal strabismus surgery.4.The changes of refraction in horizontal strabismus surgery had nothing to do with the curvature of the cornea.5.There was a dynamic transformation of refraction after operation,which would return to the preoperative level 3 months after the surgery.6.For patients undergoing monocular rectus muscle recession,optometry would be performed 1 month after operation,while for patients undergoing monocular rectus muscle recession combined its antagonistic muscle resection,optometry would be performed 3 months after operation.