Retinochoroidal (optociliary) shunt veins, blindness and optic atrophy: a non-specific sign of chronic optic nerve compression.

Fifteen patients are described in whom the triad of blindness, optic disc swelling followed by optic atrophy, and optociliary shunt veins occurred. The causes of the syndrome included spheno-orbital meningioma, optic nerve glioma, meningocele of the optic nerve, and chronic papilloedema. It is postulated that chronic compression of the intraorbital portion of the optic nerve produces gradual obstruction of the central retinal vein, thus preventing the normal passage of venous blood from the retina through the central retinal vein to the cavernous sinus. Optociliary veins are a pre-existing shunt system that allows retinal venous blood to bypass the central retinal vein and exit from the orbit via the choroidal circulation and its anastomoses.