Malarial retinopathy affecting visual function in a Malawian adult with cerebral malaria.

Cerebral malaria is uncommon in Malawian adults, at least in part because of immunity generated by exposure to endemic P. falciparum. Malarial retinopathy has been well characterized in children in sub-Saharan Africa, and Asian adults, but rarely described in adults from sub-Saharan Africa [1]. Some of the features of adult and pediatric malarial retinopathy are different [2] but it is not known whether this is due to contrasting physiology or genetics.

A 23-year-old male with a 6-day history of headache was found unconscious at home and admitted to Queen Elizabeth Central Hospital, Malawi. The past medical history included previous uncomplicated malaria. He had no history of diabetes, TB, HIV or ocular pathology.

On admission the patient was febrile and tachycardic, with a Glasgow Coma Score of 6/15 (E4, M1, V1) and absent ‘doll's eyes’ reflex. Dilated indirect ophthalmoscopy revealed bilateral retinal whitening, white-centered hemorrhages, cotton wool spots and disc hyperemia. There was no papilledema or vessel discoloration. Rapid diagnostic test for P. falciparum malaria was positive. The patient was treated for cerebral malaria and suspected subclinical seizures.

On waking 7 days after admission the patient reported poor vision in both eyes. Distance visual acuity was poor but partially improved with pinhole (Snellen acuity: Right eye 6/16 unaided, 6/7 pinhole; Left eye 6/10 unaided, 6/8 pinhole). Color vision was also reduced, worst in the right eye. Repeat ophthalmoscopy revealed similar, less severe, signs to those seen on admission (Fig. 1, A and B).

Fig. 1

Retinal images of the right and left eyes 7 days after admission with cerebral malaria (A and B), and 7 weeks later (C and D). Multiple cotton wool spots [double arrow], with patches of whitening in the peri-foveal and macular areas [arrow] are visible (A). Several small retinal hemorrhages are apparent bilaterally with some retinal edema in the left fovea (B) (arrow). After 7 weeks only small residual cotton wool spots remain bilaterally (C and D). Slight whitening in the right fovea is evident (C) but hemorrhages are no longer visible.

Five weeks after discharge visual acuity had improved further (Right eye 6/14 unaided, 6/6 pinhole; Left eye 6/5 unaided, 6/5 pinhole). Red desaturation remained in the right eye. Retinal signs had improved but not entirely resolved (Fig. 1, C and D).

Fundus abnormalities have been reported in Sudanese adults with cerebral malaria [3], but not in detail. To the best of our knowledge, resolution of retinal structure and function following cerebral malaria has been described only once in an Asian adult [4], and never in adults from sub-Saharan Africa.

The features of malarial retinopathy described in our report are similar to those described in Asian adults, including an absence of the retinal vessel abnormalities often seen in children [2]. This suggests that this phenotype might depend more on pediatric physiology and less on host or parasite genetic variables related to geography.

Conflicts of interest

Drs MacCormick and Piddock report grants from The Wellcome Trust, during the conduct of the study. Dr. Beare reports grants from The Wellcome Trust, during the conduct of the study and advisory board fees from Alimera Sciences and Novartis, outside the submitted work.

Consent

Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.