Acquired Strabismus and Diplopia as Initial Presentation Signs of Hyperthyroidism and Thyroid Eye Disease

Purpose: We evaluated the clinical characteristics of patients who recently acquired strabismus and diplopia as the initial presentations of hyperthyroidism and thyroid eye disease (TED). Methods: The medical records of patients with acquired strabismus and diplopia who visited our clinic for evaluation between January 2017 and December 2018 were retrospectively reviewed; patients diagnosed initially with hyperthyroidism and TED were included in this study. Results: A total of 410 patients were referred to our clinic for the evaluation and treatment of diplopia. Among these patients, 12 (2.9%, 12/410) showed acquired strabismus and diplopia as the initial presentation signs of hyperthyroidism and TED. The mean age of onset of diplopia was 54.7 years (range, 18-78 years). Nine patients (75%, 9/12) were male. Six male patients were active smokers at the initial presentation. Hypotropia was the most common type of strabismus (83.3%, 10/12). The mean angle of hypodeviation was 17.5 prism diopters (PD) (range, 4-40 PD). One patient showed exotropia with hypotropia and one patient showed esotropia with a bilateral up gaze limitation. Four male patients (all active smokers) underwent strabismus surgery, and one female patient underwent orbital decompression surgery. Conclusions: The incidence of acquired strabismus and diplopia as the initial presentation sign of hyperthyroidism was predominant in male patients. Hypotropia was the most common type of strabismus. Male patients who smoked were more likely to show progression to a severe clinical course than female patients.