RADIOTHERAPY FOR THYROID ORBITOPATHY - EFFECTS ON EXTRAOCULAR-MUSCLE BALANCE

Objective: To investigate the effects of radiotherapy on the restrictive ophthalmopathy and strabismus that occur with Graves' orbitopathy. Design: A prospective study of patients with motility disturbances due to thyroid orbitopathy, followed by serial quantitative measurements of ocular restrictions and deviations, both before and at 1 and 6 months after treatment with high-energy radiotherapy. Setting: Urban subspecialty private practice. Patients: Thirty-three consecutive patients with restricted extraocular movements and diplopia secondary to thyroid orbitopathy who were treated with radiotherapy were seen during an 8-year period. Measures: Maximal horizontal and vertical ductions, plus ocular deviations in primary and reading positions of gaze, were quantitatively evaluated by one clinical investigator to ensure consistency. Results: Statistically significant improvement in gaze restriction on supraduction and improvement of vertical and horizontal strabismus were demonstrated at follow-up visits after treatment. Conclusions: Although statistically significant improvement of motility disturbances were demonstrated after radiotherapy, there was less than desirable functional improvement of restrictive ophthalmopathy and strabismus; thus the usefulness of radiotherapy was limited when it was used alone to treat diplopia,