Surgical Outcomes Of The Unilateral Recession-resection In Children With Convergence Insufficiency-type Intermittent Exotropia

Part Ⅰ:Comparison of different surgery procedures for convergence insufficiency-type intermittent exotropia in childrenAims:To compare prospectively the surgical outcomes of different surgery procedures for convergence insufficiency (Cl)-type intermittent exotropia (IXT) in children.Methods:Forty-five children with Cl-type IXT were included in this prospective surgical study with6months follow-up. According to the different surgical procedures, all children were randomly divided into three groups:the unilateral medial rectus resection (UMR) group (15cases), the bilateral medial rectus resections (BMR) group (14cases) and the improved unilateral recession-resection (R&R) group (16cases). In the UMR and BMR groups, the medial rectus resection(s) were based on the distance exodeviation. In the R&R group, UMR was based on the near exodeviation while lateral rectus recession was based on the distance exodeviation. A successful surgical alignment was defined as the distant deviation in the primary gaze to be between≤10prism dioptres (PD) of exophoria/tropia and≤5PD of esophoria/tropia. The success rate, the preoperative and postoperative deviations at distance and near and near-distance differences among groups were compared. Results:At the last follow-up of6months, the success rate in the R&R (87.5%) group was significantly higher than those in the UMR (13.3%) and BMR (42.9%) groups (p=0.000and0.008); the mean exodeviations at distance and near in the R&R group were significantly different from those in the UMR and BMR groups (p=0.000and0.001); there were no significant differences in the mean near-distance differences between the R&R group and the other two groups (p>0.05).Conclusions:The improved R&R procedure in which medial rectus resection based on the near deviation with lateral rectus recession based on the distant deviation has a better alignment than the UMR and BMR surgeries for the treatment of children with Cl-type IXT. All the UMR, BMR and improved R&R surgery can reduce near-distance differences in children with CI-type IXT. Part Ⅱ Surgical outcomes of the unilateral recession-resection in childrenwith small to moderate angle convergence insufficiency-type intermittent exotropiaPurpose:To evaluate the surgical outcome of unilateral medial rectus resection based on the near deviation with lateral rectus recession based on the distant deviation (R&R) in children with convergence insufficiency (CI)-type intermittent exotropia.Methods:This prospective surgical study was performed on50consecutive children with Cl-type intermittent exotropia with1year follow-up. All patients were divided into group A (exodeviation from15PD to25PD) and group B (exodeviation from30PD to40PD) according to the preoperative distant deviation. A successful surgical alignment was defined as an exodeviation of10PD or less and esodeviation of5PD or less in primary gaze while viewing distant targets. The surgical success rate, the deviation at distance and near, and the deviation of the near-distance difference were recorded in both groups during the follow-up time.Results:There were19children in group A and31children in group B. The surgical success rate at postoperative12months were78.9%(15/19) in group A and71%(22/31) in group B, which was no significantly different between both groups.(P=0.537). Except for5children underwent reoperation because of overcorrection (4children) and undercorrection (one child) at postoperative6months and8months, there were only45children with1year follow-up. At1year postoperatively, the mean distance exodeviation were3.18±5.15PD in group A (17children) and5.96±6.43PD in group B (28children), the mean near exodeviation were6.76±8.86PD in group A and7.18±7.78PD in group B, and the mean deviation of near-distance difference reduced to3.82±5.10PD in group A and 1.21±4.36PD in group B, which were no significantly different between both groups (P>0.05). But the results in both groups during postoperative follow-up time were significantly reduced by comparison with preoperation (P=0.000). At last follow-up,78.3%of children had normal near Randot Stereotest and was more than those before operation, which was no significantly different (P>0.05).Conclusion:The titrated R&R surgery can reduce the distance and near deviation, collapse the near-distance difference and protect the binocular single vision in children with small to moderate angle Cl-type intermittent exodeviations with a low risk of consecutive esotropia.