Unique retinal lesions have been observed in some survivors of Ebola virus infection, according to a study.

In a case-control prospective study, University of Liverpool researchers compared retinal images of 82 Ebola virus disease (EVD) survivors with those of 105 control subjects seen at the 34th Regiment Military Hospital in Sierra Leone between January and June 2016.

Ophthalmic examinations included visual acuity tests, ocular anterior chamber assessment with a table-mounted slit-lamp, widefield retinal imaging and optical coherence tomography.

Prevalence of 10 different subtypes of ocular lesions were identified. Of these, one discrete subtype occurred in 12 EVD survivors and not at all in control subjects (P < .01). Characteristics of the novel lesions include wedge-shaped angulations surrounded by well-defined darkened retina, with the lesions occurring in a distribution that “suggests a neurotrophic spread into the eye from the optic nerve and along retinal ganglion cells axons,” the researchers wrote.

“This case-control study identified a novel retinal sign that appears to be specific to EVD survivors,” they said in the report. Visual acuity was not affected by the Ebola retinal lesions.

The researchers acknowledged challenges to their study, including small sample size and lack of pre-existing documentation. – by Rebecca L. Forand