Pattern strabismus in consecutive esodeviation after bilateral lateral rectus muscle recession for intermittent exotropia

PURPOSE After bilateral lateral rectus recession for intermittent exotropia, children can develop V- or A-pattern esodeviation and adopt a chin-down or chin-up position to facilitate fusion. The aim of this study was to discuss possible causes and management of this pattern.METHODS The medical records of children who developed consecutive esodeviation with V- or A-pattern strabismus after surgery for intermittent exotropia but with no pre- or postoperative oblique muscle dysfunction were reviewed retrospectively. Ductions, versions, angles of deviation, and fundus torsion were evaluated before and after surgery. Patient management and outcomes were analyzed.RESULTS A total of 37 patients were identified (mean age, 5.7 +/- 1.5 years), with a mean preoperative deviation of 30.6(Delta) +/- 5.2(Delta); no patient had a preoperative pattern strabismus. Mean bilateral lateral rectus recession was 6.2 +/- 0.9 mm. Of the 37, 34 (89%) returned postoperatively with V pattern, 2 with an A pattern, and 1 with an hourglass-like pattern. No patient showed oblique muscle dysfunction or fundus torsion. Reoperation for the consecutive deviation was performed in 19 patients, in all of whom the lateral rectus muscles were not vertically displaced. The pattern disappeared completely after reoperation and reestablishment of adequate alignment in the primary position.CONCULATIONS In our patient cohort, pattern strabismus after bilateral lateral rectus recession was successfully reversed by correction of the consecutive esodeviation.