Strabismus Surgery in Thyroid-related Ophthalmopathy

Background: Restrictive strabismus is a common feature of Thyroid-Related Ophthalmopathy (TRO) causing intractable diplopia. We reviewed the surgical outcome for TRO patients. Methods: We retrospectively reviewed patients of TRO who underwent strabismus surgery from January, 1998 to September, 2012. Preoperative characteristics were recorded such as age, sex, disease severity, presence of compressive optic neuropathy or elevation of intraocular pressure, symmetry of orbitopathy, duration between onset of TRO and surgery, smoking status, and treatment. The length of muscle recession and the numbers of strabismus surgeries was recorded for further analysis. Results: Twenty-four patients were enrolled with twelve female and twelve male in a mean age of 55.5 years (SD + 10.71). The mean number of surgery was 1.29 (SD + 0.46). Patients with aymmetric involvement at onset, presence of elevated intraocular pressure, and longer intervals between the onset of TRO and first surgery needed significantly more surgeries to correct strabismus. Factors such as age, gender, smoking status, medical treatment before surgery, presence of compressive optic neuropathy or previous orbital decompression procedure had no statistically significant effect on the number of surgery required. Conclusion: Strabismus surgery showed favorable outcomes in correcting diplopia induced by thyroid-related ophthalmopathy. The average number of surgery needed is 1.29 (±0.46) in this study, and the mean surgical effect we got was 4.09+0.26 PD/mm of rectus muscle recession.