The Ebola virus may leave a retinal scar specific to the disease, according to researchers.
“The distribution of these retinal scars or lesions provides the first observational evidence that the virus enters the eye via the optic nerve to reach the retina in a similar way to West Nile virus,” said Dr Paul Steptoe of the Royal Liverpool Hospital, in a press release.
Dr Steptoe and colleagues presented the finding in the journal Emerging Infectious Diseases. They found a novel retinal lesion following the anatomic distribution of the optic nerve axons in 14.6% of Ebola survivors and no controls, suggesting neuronal transmission as a route of ocular entry.
“Luckily, they appear to spare the central part of the eye, so vision is preserved,” Dr Steptoe said in the press release.
He added: “Our study also provides preliminary evidence that, in survivors with cataracts causing reduced vision but without evident active eye inflammation (uveitis), aqueous fluid analysis does not contain Ebola virus, therefore enabling access to cataract surgery for survivors.”
Estimates of the incidence of ocular symptoms among survivors of Ebola range from 14% to 60%. Reports of evidence of acute uveitis from ophthalmic examination range from 18% to 58%.
Uveitis classification has also varied, with 36% to 62% reported as anterior, 3% intermediate, 26% to 36% posterior and 18% to 25% panuveitis.
Little is known regarding the medium- to long-term visual outcome of survivors or the rates of background uveitis and chorioretinal lesions within the local population.