The study, conducted by a clinical research team from the University of Liverpool and Royal Liverpool Hospital in collaboration with staff from the 34th Regiment Military Hospital in Freetown, Sierra Leone, was established to assess survivors and discover more about the broad-ranging symptoms of post-Ebola Syndrome (PES).The team compared eye exams from 82 Ebola survivors who had previously reported ocular symptoms with 105 unaffected people from the military and civilian population. The results showed that 15% of survivors bore signs of retinal scarring specific to the viral disease.“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. 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,” study lead Dr Paul Steptoe said.“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 added.Viruses, such as Ebola, can rain undetected in the human body by exploiting a weakness in the immune syst. This vulnerability, called ‘immune privilege’, was initially recognised from an observation that foreign tissue transplanted into certain parts of the body – including the brain, spinal cord and eyes – did not elicit the usual immune response.Scientists believe this is because these parts of the body are too delicate and important to withstand the inflammation that’s typical of an immune response to infection.The full study can be found in the July issue of erging Infectious Diseases Journal.