Graves' ophthalmopathy: II. Correlation of clinical signs with measures derived from computed tomography.

Quantitative clinical and computed tomographic (CT) measures of Graves' ophthalmopathy were obtained in 76 patients. Significant correlation of several CT parameters of the mid-orbital axial CT slice with optic nerve involvement was established. By means of clinical measures, only limitation of ocular motility was found to correlate with the optic neuropathy. The results suggested that there were two distinct populations of patients with Graves' disease which could be segregated by CT scan and clinical evaluation, one which developed optic neuropathy and one which did not. Therefore simple measures performed on the mid-orbital slice of the CT scan are recommended for all patients with Graves' ophthalmopathy as an important adjunct to careful evaluation of extraocular muscle function, in order to identify patients at risk of developing optic neuropathy.