Eyeworld

EW RETINA 100 October 2018 by Liz Hillman EyeWorld Senior Staff Writer Emerging research on Ebola's effect on the retina Study analyzes retinal lesions that seem to be unique in Ebola survivors T hough Ebola virus disease has remained largely out of mainstream media head- lines since the historic out- break in West Africa from 2014–2016, ongoing research about the disease has continued, including about its ocular effects. The largest study of Ebola sur- vivors, published in 2016, detailed persistent conditions experienced by an estimated 17,000 survivors. From an ocular standpoint, these predominately included uveitis and conjunctivitis. 1 A more recent study continued on page 102 sought to differentiate Ebola retinal lesions from other retinal patholo- gies in West Africa. 2 "Differentiating what is due to Ebola 1 year after the infection and what is more likely secondary to other more common retinal infec- tions in West Africa, such as toxo- plasmosis chorioretinitis, is chal- lenging," said Paul Steptoe, MD, Institute of Translational Medicine, University of Liverpool, Liverpool, U.K., the study's lead author. He added, however, that "without the ability to identify what specific ophthalmic sequelae are most likely as a consequence of Ebola virus in- fection, as opposed to other retinal infections, further research would have no basis." Furthermore, Dr. Steptoe said, "[U]nderstanding the specific ocular effects of Ebola virus infection enables us to understand the visual burden of this disease. This informa- tion is useful in aiding the planning of ophthalmic care required for future epidemics and if any long- term management or intervention is required. Secondly, analyzing Ebola retinal lesions, utilizing modern imaging techniques, provides an opportunity to gain insights into the pathophysiological mechanism of the virus within the retina in a noninvasive manner." That said, Dr. Steptoe and coinvestigators, who were affiliated with University of Liverpool, the 34 Military Hospital, and Connaught Hospital, Freetown, Sierra Leone, originally began a case-controlled study, which characterized and compared retinal findings based on ultra-widefield retinal imaging of Ebola survivors compared to local controls. 3 According to Dr. Steptoe, the prevalence of retinal scarring was about 20% in both groups, but a certain retinal lesion was only identified in Ebola survivors. It is this specific type of scar- ring, being the one characteristic lesion only seen in Ebola survivors and not the control population in that study, that was analyzed in the latest paper. Fourteen survivors of Ebola virus disease were identified to have this type of retinal lesion (141 lesions identified in 22 of 27 eyes of the group). The retinas and lesions were evaluated with ultra-widefield scanning laser ophthalmoscopy, fundus autofluorescence, swept- source OCT, Humphrey visual field analysis, and spatial analysis. According to the study results, the lesions were mainly "nonpig- mented with a pale-gray appear- ance." OCT imaging, which was ob- tained on 41 of the lesions, showed "V-shaped hyperreflectivity of the Series of OCT sections of Ebola retinal lesions demonstrating varying severity A to C. The white triangles indicate an area of perilesional dark without pressure. Source: CC-BY License. © 2018 Steptoe PJ et al. JAMA Ophthalmology

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