Clinical aspects of malarial retinopathy: a critical review

ABSTRACT

This review will provide a better understanding of a set of signs known as malarial retinopathy. The discovery of this retinopathy in association with cerebral malaria is important because it best distinguishes patients with true cerebral malaria from those with coma due to other causes and incidental Plasmodium falciparum parasitemia. Identifying a comatose patient with malarial retinopathy increases the likelihood of an accurate severe or cerebral malaria diagnosis. As the World Health Organization does not specify that malarial retinopathy is one of the factors included in determining a cerebral malaria diagnosis, there are significant false-positive diagnoses of cerebral malaria. Once a cerebral malaria diagnosis is assigned, other possibilities and treatments are often excluded making an incorrect diagnosis of cerebral malaria potentially fatal. However, Plasmodium falciparum may also contribute to coma in some children with retinopathy-negative cerebral malaria, as this group is still not clinically well characterized, so all children with the WHO definition of cerebral malaria should be treated for severe malaria. Nevertheless, by raising awareness about malarial retinopathy, there could be a greater potential to accurately diagnose cerebral malaria and thus achieve more positive patient outcomes in the future. This literary review aims to raise awareness of the retinopathy by defining what it is to non-experts, explaining its pathology, clarifying the techniques needed to accurately diagnose malarial retinopathy, as well as the barriers that prevent clinicians from providing a proper diagnosis in malaria-endemic regions; and finally, discuss future directions to continue the study of malarial retinopathy.

KEYWORDS:

• Cerebral malaria
• malarial retinopathy
• retina
• fundoscopy
• macular whitening
• vessel discoloration

Acknowledgments

The author would like to thank Professor Karen Oliveira and Anderson Herculano along with his colleagues at the Laboratory of Experimental Neuropharmacology, Federal University of Pará, Belém, Brazil for their guidance, and support throughout the academic year. He would also like to thank the Fulbright US Student Program, the Brazilian Fulbright Commission, and the Federal University of Pará for financing the author’s research endeavors and providing such an enriching educational and cultural opportunity. An additional thanks to Dr. Nicholas Beare and the University of Liverpool Department of Eye and Vision Science, Blantyre Malaria Project in Queen Elizabeth Central Hospital, and VisionQuest Biomedical Inc. for sharing the retinal image data used in this article and to Dr. Terrie Taylor and Dr. Vinayak Joshi for their invaluable contributions to the accuracy of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author’s contributions

The author wrote the final manuscript. Dr. Karen Oliveira and Dr. Anderson Herculano helped edit and approve the final manuscript.

Additional information

Funding

This manuscript was funded by the Federal University of Pará and the Fulbright US Student Program.