[Thyroid ophthalmopathy ad a unique clinical manifestation of thyrotoxicosis].

Thyroid ophthalmopathy (TO) or Graves ophthalmopathy embraces a broad range of eye abnormalities which up to 90% of patients with hyperthyroidism (HT) are affected with. In some 10% of TO patients, this may begin oligosymptomatically, often with double vision and with neither clinical nor biochemical signs of thyroid disease. It is imperative to carry out a differential diagnosis with countless other causes for double vision and other eye socket processes. Ophthalmopathy may also occur in patients with hypothyroidism and for this reason some authors prefer to refer to it as dysthyroid orbitopathy. We present four cases of TO in which double vision was the first clinical sign of TO which in one case became severe, in two cases preceded hyperthyroid symptomatology and in the remaining case happened after hyperthyroidism had been corrected. The most valuable diagnostic test was orbit computerised tomography (CT) scan, which proved positive in all cases, and that, along with clinical tests and thyroid function data, confirmed a diagnosis of TO. All initially improved with corticosteroids although none completely regained eye movement during the time they were under supervision. The same happens in about 50% of patients who do not respond to treatment either with corticosteroids or with radiotherapy, and response is usually incomplete in those who do so respond.