THE DIAGNOSTIC HISTOPATHOLOGIC FEATURES OF OCULAR MALARIA

Background: The ocular complications in patients with malaria have bee n studied clinically by many investigators, but the histopathologic ch anges were rarely described and generally regarded as nonspecific. Met hods: The eye of a 53-year-old man who died of chloroquine-resistant P lasmodium falciparum malaria was studied by brightfield and polarized light microscopy. Findings: An epibulbar hemorrhage that involved the conjunctiva, episclera, and tendinous insertion of the medial rectus m uscle was present. Cytoadherence and rosetting of the parasitized eryt hrocytes were observed within the partially occluded lumens of small r etinal and uveal blood vessels. The birefringence of hemozoin (malaria l pigment) within the lumens of small ocular blood vessels and in the hemorrhagic epibulbar area was demonstrated by polarized light. Conclu sion: Birefringent hemozoinemia in vascular lumens of ocular tissues i ndicates systemic malarial infestation by any of the four species of m alaria. Cytoadherence and rosetting of the parasitized erythrocytes in side ocular capillaries and venules is diagnostic of P. falciparum and is an important cause of ocular hemorrhage.