The TRH test: its value in the diagnosis of Graves' ophthalmopathy

When a goiter or hyperthyroidism is absent, the diagnosis of ophthalmic Graves' disease is often difficult. We evaluated the thyrotropin (TSH) response to intravenously administered thyrotropin-releasing hormone (TRH) in fourteen patients presenting with proptosis or lid retraction. All of them had normal results with routine thyroid function tests and in most a T3 suppression test and orbital ultrasonography were performed. We found an absent or impaired response to TRH in the patients with Graves' ophthalmopathy which correlates well with their having a non-suppressible thyroid gland. Patients with orbital tumours, pseudotumours or congenital lid retraction responded normally to TRH. The TRH test was easier and as reliable as the T3 suppression test in the investigation of a patient with suspected Graves' disease.