Improvement in Both Primary and Eccentric Ocular Alignment After Thyroid Eye Disease-Strabismus Surgery With Tenon's Recession.

PURPOSE: To evaluate the improvement in primary and eccentric gaze ocular alignment in thyroid eye disease (TED) patients undergoing horizontal strabismus surgery with Tenon's recession. METHODS: This is an Institutional Review Board-approved retrospective analysis of TED patients undergoing horizontal strabismus surgery for esotropia. The study included all patients from 2007 to 2016 operated on by a single surgeon at Columbia University Medical Center. Surgical success was defined as the ability to fuse at both near and distance either without prismatic correction or with less than 10 prism diopters (PD) of correction. Measurements of ocular alignment were also made in eccentric fields of gaze. This study was Health Insurance Portability and Accountability Act compliant with protection of individually identifiable information. RESULTS: Thirty-eight patients with TED and restrictive horizontal strabismus underwent unilateral or bilateral medial rectus recession to relieve diplopia. All patients underwent Tenon's recession with dissection of Tenon's from the overlying conjunctiva permitting it to retract into the orbit. Overall the success rate was 87% with a reoperation rate of 7.9%. The improvement in horizontal deviation in both primary and eccentric gaze was statistically significant (p < 0.001). The change in vertical deviation in the 5 cardinal positions of gaze was not statistically significant. The postoperative change in vertical deviation was not proportional to the preoperative horizontal deviation or the amount of horizontal recession. CONCLUSIONS: Due to the preoperative incomitance of ocular deviations in TED patients, persistent postoperative eccentric misalignment is expected. The addition of Tenon's recession to TED-horizontal strabismus surgery led to statistically significant improvement in ocular alignment in both primary and eccentric gaze. This is the first study of TED-strabismus surgery to analyze the postoperative results in positions outside of primary and reading gaze. The authors postulate that the release of scar tissue by the addition of Tenon's recession contributes to these improvements.