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The diagnostic histopathologic features of ocular malaria
A A Hidayat1, R M Nalbandian, D W Sammons
1Department of Ophthalmic Pathology, Armed Forces Institute of Pathology, Washington, DC 20306-6000.
Ophthalmology
|August 1, 1993
Summary
Histopathology reveals malarial pigment (hemozoin) in ocular blood vessels, indicating systemic malaria. Parasite cytoadherence and rosetting within ocular vessels are diagnostic of Plasmodium falciparum malaria and cause ocular hemorrhage.
Area of Science:
- Ophthalmology
- Infectious Diseases
- Pathology
Background:
- Ocular complications of malaria are clinically studied, but histopathologic changes are poorly described.
- Previous studies regarded ocular malarial changes as nonspecific.
Observation:
- A case of fatal chloroquine-resistant Plasmodium falciparum malaria was examined histopathologically.
- Microscopy revealed epibulbar hemorrhage and vascular changes in the ocular tissues.
Findings:
- Parasitized erythrocytes showed cytoadherence and rosetting within occluded small retinal and uveal blood vessels.
- Birefringent hemozoin (malarial pigment) was observed in ocular blood vessels and hemorrhagic areas.
- Polarized light microscopy confirmed hemozoin birefringence.
Implications:
- Birefringent hemozoinemia in ocular vessels signifies systemic malaria infection by any Plasmodium species.
- Vascular cytoadherence and rosetting are diagnostic of P. falciparum malaria.
- These findings highlight a significant cause of ocular hemorrhage in severe malaria.