Central retinal vein occlusion due to hyperviscosity syndrome.

A 57-year-old man with no previous medical history entered the emergency department with 2 days of painless vision loss in the left eye. The patient was diagnosed with central retinal vein occlusion (CRVO) and admitted for treatment. Further work-up revealed that the cause of his CRVO was a hyperviscosity syndrome secondary to multiple myeloma. The patient received two rounds of plasmapheresis with slight recovery of vision and was discharged 28 days later.