[Role of ultrasonic B-scanning in differential diagnosis and prognosis of the course of optic neuritis].

The possibility of using ultrasonic scanning in differential diagnosis of optic neuritis (ON) and anterior ischemic neuropathy (AIN) and the prognostic significance of the results were evaluated. The thickness of retrobulbar part of the optic nerve directly behind the eye was measured by echographic B method in patients with ON and AIN. The thickness of the retrobulbar part of the involved and paired optic nerve was more than 0.7 mm in 90% patients with ON, which can be considered as an additional clinical sign of ON. Thickening of the retrobulbar part of the optic nerve is not characteristic of AIN. In patients with disseminated sclerosis ON is associated with less pronounced thickening of the retrobulbar part of the optic nerve than in idiopathic ON, which agrees with the pathogenesis and pathomorphology of disseminated sclerosis. The degree of optic nerve thickening in ON in patients with disseminated sclerosis is prognostically insignificant, while in idiopathic ON more than 2 mm asymmetry of the retrobulbar part of the involved and paired optic nerve is a sign predicting a long course of the disease and maybe incomplete recovery of vision. Thickening of the involved optic nerve by less than 1.7 mm is associated with a better prognosis as regards the time and completeness of vision restoration.