Dilated orbital vein causing Valsalva-induced proptosis.

This case report highlights intermittent proptosis precipitated by exercise or Valsalva maneuvers. Conventional orbital computed tomography scan and catheter angiography did not disclose any orbital vascular lesion. Orbital B-scan ultrasonography, however, before and after a Valsalva maneuver demonstrated intermittent orbital vein dilation adjacent to the optic nerve of the left eye. Clinicians should be aware that anatomic venous variations and vascular malformations including orbital varices may produce a characteristic symptom of recurrent proptosis with Valsalva or head position. Conventional structural orbital imaging (e.g., computed tomography or magnetic resonance imaging) may not demonstrate a lesion.