Teaching Video NeuroImages: positional exophthalmos in orbital varices.

A 56-year-old woman presented with intermittent vertical diplopia and exophthalmos of the left eye, which become apparent when she was bending over. Examination disclosed mild limitation of supraduction and lid lag of the left eye. Bending over induced profound exophthalmos of the left eye (video) and aggravated vertical diplopia. The exophthalmos was confirmed by an exophthalmometer, which showed 16 mm right eye/15 mm left eye in the supine position, and 16 mm right eye/19 mm left eye in the prone position. Orbital MRI demonstrated enhancing lesions in the left retrobulbar area in the supine position (figure, A), which became prominent in the prone position (figure, B). Orbital varices are congenital vascular abnormalities with the presentation of intermittent, positional exophthalmos due to the constraint of the venous return by certain head postures.1