branch retinal artery occlusion (brao) in polycythemia vera (pv): a rare case report from surabaya, indonesia

Polycythemia vera (pv) is a chronic myeloproliferative neoplasm (mpn) characterized by a significant, independent elevation in red blood cell count. while the pv prevalence is estimated at 22 per 100,000 population, visual disturbances occur in only 13% of cases, and retinal artery or vein occlusion presenting as the initial diagnosis of pv is rarely reported. we report the case of a 40-year-old male who presented with sudden right eye vision loss, described as being covered by a dark curtain, accompanied by a headache. ocular examination revealed decreased visual acuity. a complete blood count showed elevated hemoglobin (18.5 g/dl), hematocrit (54.5%), and leukocytosis, raising suspicion for mpn. pv was confirmed by a positive jak2 v617f mutation. further ocular examination indicated subretinal hemorrhage, retinal opacification, and cystoid macular edema (via oct). the patient was treated with acetylsalicylic acid (asa) and serial phlebotomy, resulting in improved vision and reduced retinal occlusion. retinal artery occlusion, specifically branch retinal artery occlusion (brao) in this case, is an uncommon pv complication. the pathogenesis is primarily linked to increased blood viscosity from high hematocrit, which increases the risk of arterial thrombosis. although rare, retinal occlusion can be an initial manifestation of pv, necessitating close monitoring to prevent recurrent vascular events and vision loss.