Recovery From Suppression With Successful Motor Alignment After Surgery for Intermittent Exotropia

Abstract

Purpose: To investigate recovery from suppression when the target motor alignment is achieved following surgery for intermittent exotropia. Methods: The medical records of 237 patients who underwent surgery for exotropia were retrospectively reviewed. The age at surgery, sex, preoperative angle of deviation, suppression status, and near stereopsis were investigated. Suppression status was classified as no, alternate, or constant suppression. Target motor alignment was defined as 10 prism diopters (PD) or less of exodeviation or 2 PD of esodeviation at the final visit. Results: The mean age at surgery was 8.2 +/- 3.2 years and 115 (48.5%) patients were male. The preoperative angle of deviation was 26.3 +/- 5.9 PD and the follow-up postoperative period was 21.6 +/- 7.6 months. The preoperative suppression status included 23 (9.7%), 55 (23.2%), and 159 (67.1%) patients who showed no, alternate, or constant suppression, respectively. Two hundred fifteen (90.7%) patients obtained the target motor alignment by the final visit. Of the 144 patients who demonstrated constant suppression preoperatively but achieved the target motor alignment postoperatively, 12 (8.3%) patients demonstrated residual suppression. All 12 of these patients had a preoperative angle of exotropia of greater than 20 PD. Conclusions: Most patients undergoing surgery for intermittent exotropia obtained both successful motor alignment and fusion postoperatively. However, successful motor alignment did not guarantee recovery of suppression when the preoperative angle of exotropia was greater than 20 PD. The preoperative factors and functional implications underlying this finding are unclear and merit further study.