A Research On The Optical Timing And Way Of Surgical Treatment For The Basic Type Of Intermittent Exotropia

Objective:To explore the influencing factors of the functionally healing of the basic type.Of intermittent exotropia(X(T))and compare the effects of bilateral lateral rectus recession(BLR-rec)and d unilateral lateral rectus recession combined with medial rectus resection(R&R),and to provide guidance for the clinical decision on the timing of surgery and the choice of surgical approach.Methods:Prospective case observation study and case-control study.132 cases with basic type of X(T)were collected in Tianjin Eye Hospital from Aug.2015 to Mar.2016.Their clinical data were analyzed which included preoperational Newcastle control score,Worth four-dot test at 6 m and 33cm,intermittent exotropia questionnaire(IXTQ)and Pre-and post-operational ocular alignment,stereopsis(Titmus,Frisby,Functional Visual Analyzer(FVA),Frisby Davis Distance(FD2)).Among them,66 cases of basic type X(T)with ocular alignment ranging from-25 PD to-50 PD were randomly divided into the group of BLR-rec and R&R.Orthophoria was defined as between 8 PD exophoria/tropia and 4 PD esophoria/tropia;undercorrection was defined as>8 PD of exophoria/tropia and overcorrection was defined as>4 PD of esophoria/tropia in primary while viewing distant targets.It was in order to explore the influencing factors of postoperative eye position and stereoscopic reconstruction and to find the cutoff point and way of surgery.Result:At postoperative 6 months,there were 84 cases of orthopedic position,4 cases of overcorrection and 44 cases of undercorrection.The orthophoria rate was 63.6%.The deviation at postoperative 1 day and peripheral fusion function were statistically significant to postoperative eye position(respectively P=0.037,b=-0.093;P=0.017,b=0.725).But the ROC curve of the latter was not statistically significant.72 patients with 0-+10PD on the postoperative 1 day got orthopedic position in postoperative 6months.The influence of postoperative eye position on stereopsis with was statistically significant(c~2=4.036,P=0.045);The age of onset and the preoperative distance stereoacuity with FD2 were the influencing factors of postoperative distance stereo reconstruction(P=0.023,b=-0.213;P=0.036,b=0.036)by Logistic regression analysis.With ROC curve analysis,the age of onset was not statistically significant,while the preoperative distance stereoacuity with FD2 was statistically significant.The best cutoff point was 22.5”with FD2 at 6m.Poorer child IXTQ was correlated to age(r=-0.453,P=0.000),clinic distance control score(r=-0.254,P=0.023).The result of logistic regression of child HRQOL was age.y>12 groups as a reference,9<y?12groups OR=8.243,P=0.108,6<y?9 group OR=22.284,P=0.025,5?y?6 groups OR=64.929,P=0.001,with the increase of age,the quality of life score decreased,9<y?12 group decreased significantly.In the BLR-rec group,the orthophoria rate of eye position was 68.75%,undercorrection rate was 18.75%,and overcorrection rate was 12.5%on postoperative 6 months.The R&R group,the orthophoria rate of eye position was 47.06%,undercorrection rate of 35.29%,and overcorrection rate was17.65%on postoperative 6 months.There was no significant difference in the eye position on postoperative 6 months between the two groups(P=0.435).The postoperative functional cure rate of the BLR-rec group was 56.25%.That of R&R group was 29.41%,There was no significant difference in the functional cure rate between the two groups(P=0.228).Conclusion:The eye position on the postoperative 1 day influenced the orthophoria rate of the postoperative eye position.The optimal alignment on postoperative 1day was 0~10PD.Postoperative distance stereopsis was improved well and the surgery should be done before the distance stereoacuity was better than 22.5 seconds with FD2 at 6 meters.The poor child IXTQ was correlated to larger angle of deviation,poor control and being older.