Surgical management of strabismus for dysthyroid ophthalmopathy.

BACKGROUND The study reports our 8-year experience in the surgical treatment of restrictive myopathy resulting from dysthyroid ophthalmopathy. We tried to determine the factors that contributed to favorable surgical outcomes. METHODS The charts of patients who had surgical treatment for strabismus related to dysthyroid ophthalmopathy at Chang Gung Memorial Hospital between January 1995 and December 2002 (n=25) were retrospectively reviewed, and factors that possibly influenced the outcome were statistically analyzed for significance. RESULTS The mean pre-operative vertical deviation of the 25 patients was 23.3 prism diopters and the pre-operative horizontal deviation was 11.3 prism diopters. The mean follow-up time was 29.7 months. Each patient had strabismus surgery an average of 1.5 times. The majority of patients (84%) were satisfied with the result. No significant difference in the success rate was evident between patients who waited less than 3 months before the surgery and those who waited for a longer period. The repeat surgery rate was significantly higher in the latter group. A shorter duration of diplopia and smaller angle of pre-operative horizontal deviation were contributors towards a favorable outcome. CONCLUSIONS A waiting time of less than 3 months prior to treatment of strabismus associated with dysthyroid ophthalmopathy produced a favorable outcome. The duration of diplopia and the pre-operative angle of horizontal deviation were the most important prognostic factors.