Effects of orbital radiotherapy on extraocular muscles in Graves' ophthalmopathy

Oculomotor disturbances commonly occur as manifestations of Graves' ophthalmopathy. The authors investigated the outcome of this disorder following external-beam orbital radiotherapy. They conducted a prospective study on 15 patients to assess the extent of ophthalmopathy by clinical evaluation, and measurement of the amplitude of gaze and the thickness of the extraocular muscles on computed axial tomography (CAT-scan) before and after orbital radiotherapy. This paper reports the results of this study and the effects of radiotherapy on the extraocular muscles are discussed.