London: Ebola survivors have retinal scars that is specific to the disease, although it does not cause vision loss, say scientists who studied the lasting effects of the deadly virus.
Scientists from the University of Liverpool in the UK conducted a study of Ebola survivors to determine if the virus has any specific effects on the back on the eye using an ultra widefield retinal camera.
“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 Paul Steptoe from the University of Liverpool.
“Luckily, they appear to spare the central part of the eye so vision is preserved. Follow up studies are ongoing to assess for any potential recurrence of Ebola eye disease," Steptoe said.
Two years on from the Ebola outbreak in West Africa, many survivors are still presenting with symptoms of post-Ebola syndrome (PES), including joint and muscle pains and psychiatric and neurological problems.
Viruses, like Ebola, can stay hidden in our bodies by exploiting a vulnerability in our immune systems. This vulnerability is called “immune privilege," and comes from an old observation that foreign tissue transplanted into certain parts of the body do not elicit the usual immune response. This includes the brain, spinal cord, and eyes.
Scientists believe this is because the brain, spinal cord, and eyes are simply too delicate and important to withstand the inflammation that’s typical of an immune response.
Researchers compared eye examinations of PES sufferers in Sierra Leone and the control population.
A total of 82 Ebola survivors who had previously reported ocular symptoms and 105 unaffected controls from civilian and military personnel underwent ophthalmic examination, including widefield retinal imaging.
The results of the research show that around 15% of Ebola survivors examined have a retinal scar that appears specific to the disease.
“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," Steptoe said.