Summary

A 60-year-old woman with no premorbidities presented with symptoms of sudden painless vision loss in the left eye (LE). Best-corrected visual acuity in the LE was counting fingers close to face. A relative afferent pupillary defect was observed in the LE. Ocular fundus examination of LE was suggestive of central retinal artery occlusion. Systemic evaluation revealed splenomegaly and normal cardiac and carotid arteries. Haematological investigations revealed increased haemoglobin, haematocrit, platelet count and leucocytosis with low erythrocyte sedimentation rate (ESR). Features of myeloproliferative neoplasm were noted on bone marrow aspiration. An assay for JAK2 mutation was positive. Since erythropoietin levels were normal, a diagnosis of primary polycythaemia vera was made and treated with aspirin and phlebotomy twice weekly until the target haematocrit of under 45% was achieved.