Concomitant multiple myeloma spectrum diagnosis in a central retinal vein occlusion: a case report and review.

Multiple myeloma is a neoplastic plasma-cell disorder resulting from malignant plasma cells in the bone marrow. It can cause a hyperviscosity syndrome secondary to the paraproteinaemia associated with the disease. The increased hyperviscosity can lead to retinal vein occlusions and other ocular problems that may challenge clinicians. In patients with multiple myeloma and hypertension and/or diabetes mellitus, retinal changes appear similar and changes due to one disease or the other may be difficult to determine. A 48-year-old white female presented to the clinic with a complaint of blurry vision in her left eye. A full comprehensive ocular examination revealed a central retinal vein occlusion presumably from the patient's history of hypertension, diabetes mellitus and hypercholesterolaemia. Further bloodwork revealed monoclonal protein in the patient's serum and an increased percentage of plasma cells in the bone marrow. She was diagnosed with monoclonal gammopathy of undetermined significance, part of the multiple myeloma disease spectrum. She was referred to a retinal specialist for initiation of intravitreal injections of anti-vascular endothelial growth factor. Multiple myeloma has been implicated in younger patients as an underlying cause of retinal vein occlusions. Multiple myeloma should be considered as a differential diagnosis in young patients with retinal vein occlusions, even if other risk factors for venous occlusion like hypertension, diabetes mellitus and hypercholesterolaemia are present. Timely referral to the patient's primary care physician and haematologist is important for appropriate treatment and control of underlying systemic conditions.