Artery, vein, neither, both?

Combined central retinal vein and central retinal artery occlusion is a rare complication of compressive or infiltrative optic nerve disease. In this case combined retinal arterial and venous occlusive disease was the presenting sign of metastatic adenocarcinoma to the optic nerve sheath. An optic nerve sheath biopsy led to the diagnosis. Clinicians should be aware that retinal vascular disease can be due to optic nerve disorders including metastatic carcinoma.