Outcomes and risk factors of surgical management of thyroid eye disease-related diplopia

Objectives: To evaluate the outcomes of strabismus surgery in patients with thyroid eye disease (TED) and to assess the influence of preceding treatments such as steroid administration, orbital decompression and radiotherapy. Methods: Retrospective study on a cohort of patients with TED undergoing strabismus surgery. Data collection included clinical features, smoking status, preceding steroid therapy, orbital radiation therapy and orbital decompression. Qualitative evaluation, assessing diplopia and quality of life and quantitative evaluation, assessing the eye misalignment were analysed 1 year after the last squint surgical procedure. Results: Seventy-nine patients were identified. Ninety-five surgical procedures were performed on 92 eyes. A significant overall improvement of ocular motility was registered (p < 0.001, paired t-test). Forty-five (57%) patients had excellent outcomes, twenty-three (29%) had good outcomes and eleven (14%) had poor outcomes. The average number of muscles operated was significantly greater in patients who underwent orbital bone decompression (1.58 +/- 0.63; p = 0.0082; 95% CI 1.413-10.214). Quantitative and qualitative outcomes were not associated with the preceding therapy: steroid (p = 0.75), radiotherapy (p = 0.95) or orbital bone decompression (p = 0.25). The success rate was no different between adjustable and fixed sutures (p = 0.8). Conclusion: Strabismus surgery in TED patients resulted in a high success rate in reducing diplopia and improving ocular motility. The success rate was not negatively associated with previous therapies. Indeed, resolution of diplopia required more squint procedures in patients who have previously undergone to orbital decompression.