Abstract
Two patients presenting with unilateral visual loss were found to have compressive optic neuropathy caused by dysthyroid orbitopathy. In addition to typical enlargement of the belly of the extraocular muscles, computerized axial tomography scanning revealed diffuse infiltration of the periorbital sinuses associated with partial bony wall destruction of the ethmoidal sinuses. A biopsy taken from the maxillary sinus mucosa of one of the patients revealed the presence of chronic inflammation and many eosinophils. The differential diagnosis of the latter findings is presented and the possible etiological factors are discussed.