The contribution of echography in the diagnosis of proptosis

Echography was used to examine the retro-bulbar space of 150 patients with protosis. An NE Diasonograph was used with an 8 MHz probe using a water bath in the supine position. Lesions were classified ultrasonically as (1) tumour, (2) inflammatory oedema (including pseudo-tumour or other granulomas), (3) traumatic, (4) dysthyroid ophthalmopathy, (5) normal. Thirty-one patients were placed in the tumour group but three of these were subsequently found to have granulomas. In addition, one patient with a normal ultrasonic appearance, was found to have a meningioma en plaque at operation. There were no false positive results in the inflammatory group but again one patient with a normal ultrasonic appearance was eventually diagnosed as having an orbital inflammatory process. The ultrasonic findings in inflammatory disease are non-specific and three were found to be associated with or possibly caused by venous thrombosis or arteritis of the orbit. The changes have to be distinguished from the thyroid ophthalmopathy but this disorder is generally bilateral which is unusual in inflammatory disease. Traumatic oedema and haemorrhage are distinguidhed by the obvious antecedent history. Because of the variability of the amount and position of the retrobulbar fat in the posterior part of the orbit, it is necessary to make a comparative scan of the normal orbit in all patients with suspected retro-bulbar pathology.