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.