Idiopathic orbital inflammation and Graves ophthalmopathy.

Idiopathic orbital inflammation (IOI) is a poorly understood disease entity in which an orbital inflammatory process is found with, by definition, no identifiable local or systemic cause. Graves ophthalmopathy (GO) is often mentioned as a disease to exclude in the diagnosis of IOI. In the Orbital Clinic of the University Medical Center Utrecht, we have encountered 4 patients in whom diagnoses of both IOI and GO were made at different times. In this case series, we describe the clinical and diagnostic features of these patients, show that both IOI and GO can occur at different times in the same patient, and demonstrate the ways the diseases can be differentiated.