Comparing optical coherence tomography findings in different aetiologies of infectious necrotising retinitis

AimsTo compare optical coherence tomography (OCT) features of active necrotising infectious retinitis (NIR) due to toxoplasmosis or herpesviruses and to determine distinctive OCT signs for these two causes of infectious retinitis.MethodsOCT scans from eyes with active NIR due to varicella zoster virus (VZV), herpes simplex virus (HSV), cytomegalovirus (CMV), and toxoplasmosis (TOXO) were reviewed. All images were evaluated for the presence of previously described OCT findings in TOXO-NIR and compared with the viral group. New OCT findings were recorded and compared. Retinal and choroidal thickness were measured at the site of NIR and compared.Results10 eyes diagnosed with TOXO-NIR and 13 eyes affected by viral-NIR (9 CMV and 4 VZV) were analysed. All eyes showed full thickness hyper-reflectivity, disruption of the retina and a variable degree of vitritis. Among previously described OCT signs, hyper-reflective oval deposits and hypo-reflectivity of the choroid had a higher prevalence in TOXO (p=0.018 and p