Comparison Of Two Surgery Procedures For Basic-type Intermittent Exotropia

PurposeTo compare surgical outcomes after bilateral lateral rectus recession(BLR-rec)and unilateral lateral rectus recession-medial rectus resection(R&R)for the treatment of basic-type intermittent exotropia.MethodsConsecutive 68 patients who underwent BLR-rec(n=36)or R&R(n=32)for treatment of basic-type intermittent exotropia between May 2012 and October 2014 in the first affiliated Hospital of Nanjing Medical University were recruited for this study.All patients underwent>1 years of follow-up.The success rate according to postoperative angle of deviation,near stereoscopic vision recovery,the recurrence rate among the BLR-rec and the R&R groups were compared.Results1.The general situation of the two groups(A,B)of patients before surgery:the gender differences between the two groups had no statistically significant(X2 = 0.500,P = 0.338);The surgical age,the duration of the oblique vision,the diopter,corrected visual acuity,the preoperative strabismus,the follow-up time,the difference of preoperative stereoscopic function all had no statistically significant;2.1.The position rate of ocular position was 83.3%after one week by bilateral lateral rectus recession(group A),and the rate was 81.2%after one week by unilateral lateral rectus recession-medial rectus resection(group B),the difference between two groups of position rate of ocular position had no statistical significance(X2 =0.051,P=0.822);2.2.The position rate of ocular position was 77.8%after one year by bilateral lateral rectus recession(group A),the rate was 53.1%after one year by unilateral lateral rectus recession-medial rectus resection(group B),the difference between the two groups of position rate of ocular position had no statistical significance(X2=3.061,P<0.05),the position rate of ocular position of group A was higher than group B after surgery.3.The tertiary stereo visual function recovery rate was 61.1%after one year by bilateral lateral rectus recession(group A),and the rate was 65.6%by unilateral lateral rectus recession-medial rectus resection(group B),there was no statistically significant difference between the two groups(X2 = 0.148,P = 0.700).4.1.Follow-up the changes in strabismus degree after the operation randomly,the average of strabismus rate in one year of the two groups was 1.810 ± 5.148PD,-2.560 ± 4.595PD respectively after one week by bilateral lateral rectus recession,the difference of the sample t(t=4.541,P<0.001)test was statistically significant.The mean value of oblique diplopia was 2.500 ± 6.559PD,-6.563 after one week by unilateral lateral rectus recession-medial rectus resection.The difference of the sample t(t=11.957,p<0.001)test was statistically significant.Each kind of the surgical method used to treat the basic intermittent exotropia could retrograde the postoperative eye position.4.2.The postoperative retrograde retraction volume was 4.370 ± 3.729PD bilateral lateral rectus recession(group A)(t= 3.288,P = 0.002);the monocular external rectus migration joint internal rectus shortening retraction volume was 9.063±4.288PD.The difference between the two groups was statistically significant.The postoperative strabismus regression in one year by unilateral lateral rectus recession-medial rectus resection(group B)was higher than the group by bilateral lateral rectus recession.ConclusionsThere were differences in the curative effect of the basic type of intermittent exotropia by different operation methods,and there were no differences in the two groups of the position rate of ocular position after the two kinds of operation.After 1 year,there were differences in statistics between the two groups of the position rate of ocular position.The position rate of ocular position postoperative patients by bilateral lateral rectus recession(Group A)was higher than the group by unilateral lateral rectus recession-medial rectus resection(Group B).There was no significant difference in the recovery rate of the three-level stereoscopic visual function after two kinds of operation methods.The patients with unilateral lateral rectus recession-medial rectus resection(Group B)had higher strabismus regression than those with bilateral lateral rectus recession(Group A).Surgical treatment of patients with basic intermittent exotropia may give priority to the isometric surgery of bilateral lateral rectus recession.