Ocular ductions after rectus muscle recession and resection in thyroid eye disease

Background: Recession and resection of rectus muscles for correction of strabismus in Thyroid Eye Disease (TED) is relatively unpopular as it is assumed to enhance the restriction of ocular ductions. Therefore, the purpose of this study was to compare ductions of recession only and recess/resect procedures. Methods: We retrospectively reviewed the charts of 119 patients who underwent strabismus surgery for TED from 1991 to 2015, of which 102 were included in the present study. Forty-six interventions were performed on horizontal, 56 on vertical rectus muscles; comprising 41 recess/resect surgeries for horizontal deviations, and 7 in patients with vertical strabismus. Ocular ductions and alignment were evaluated preoperatively and at 3 and 12 months postoperatively. Results: Both recessions as well as recess/resect procedures resulted in improved abduction and elevation, respectively. At the exam 3 months postoperatively, median abduction for the recession only group and the recess/resect group were 27.5° and 35°, respectively. The similar figures for elevation were 25° and 10°, respectively. Neither were statistically significant. No restricted adduction or depression was seen in the recess/resect surgeries groups with lateral or superior rectus resection. None of the patients showed unusual postoperative inflammation or conjunctival scarring. Conclusion: In this retrospective analysis, we found an equal effect on ocular ductions in patients with TED when comparing recess/resect eye muscle surgery to recess only procedures. In TED patients with large horizontal angle deviations and abduction deficit, medial rectus recession and lateral rectus resection surgery can be considered. Muscle resections in TED do not seem to have a clinically relevant risk to increase the restriction of ocular ductions but rather improve ductions in the restricted directions of gaze.