[Computerized tomography of the orbit in Graves' ophthalmopathy. New observations]

In order to evaluate Graves' ophthalmopathy new CT parameters have been introduced such as: the diameters of the five extraocular muscles, the value of their addition, the grade of apical crowding, the enlargement of optic nerve sheaths and of the superior ophthalmic vein, and the anterior displacement of the lacrimal gland. On this subject we report our further experience after reviewing 68 cases in which the new ocular parameters were correlated with altered ocular motility and optic neuropathy. The results confirmed our previous study, dealing with several groups of patients, which at the moment seem to be 2, instead of 3 groups: a) patients with increase in both muscular and fatty tissue (54/68 cases); b) patients with main or exclusive increase in fatty tissue (14/68 cases). Relevant clinical signs were present only in the first group of patients, where the medial, inferior and superior muscles were affected in 53/55, 53/55 and 50/55 cases respectively. A muscle increase by nearly 50% was more frequently found in cases with altered ocular motility, an increase by 90% was often associated with optic neuropathy. In case of optic neuropathy apical crowding was often observed, mainly in coronal scans, together with significant enlargement of the optic nerve sheath and of the superior ophthalmic vein. As to proptosis, preseptal area and anterior displacement of the lacrimal gland, they demonstrated lower correlation with the reference symptoms, even though their occurrence was high in symptomatic patients.