J.DING1, A.SHRIVASTAV2, S.W.ZHOU3, J.M.LEE4, C.H.CHUA4, R.MAITRA2, S.NATARAJAN5, R.AGRAWAL4
MOH Holdings Pte Ltd (MOHH)1, Radical Health, New Delhi, India2, Khoo Teck Puat Hospital3, Tan Tock Seng Hospital4, Aditya Jyot Eye Hospital5
Severe COVID-19 infection is known to cause multi-organ dysfunction, with evidence suggestive of inflammatory endothelial dysfunction and microvascular thrombosis as possible patho-mechanisms. Though there are limited reports of significant COVID-19 related ocular complications, there is a lack of research to rule out potential intra-ocular microvascular compromise; Having one the highest blood flow within the body, the choroid may be especially susceptible. Using ‘Choroidal Vascularity Index’ (CVI), an Optical Coherence Tomography (OCT) based surrogate marker, this study aims to quantitatively evaluate for alterations in the choroidal angioarchitecture of COVID-19 patients.
This comparative study recruited 56 COVID-19 patients (111 eyes) and 61 healthy individuals (120 eyes), both groups with no history of ocular diseases. CVI and choroidal thickness (CT) were derived from OCT images using a purpose built fully automated software. A linear mixed model with age and gender as covariates was employed to compare CVI and CT between groups.
COVID-19 patients had significantly higher subfoveal (81.3um vs 86.8um, p=0.017), temporal (78.8um vs 84.3um, p=0.005), nasal (87.5um vs 95.1um, p=0.001) and average CT (82.5um vs 88.7um, p=0.001).
COVID-19 patients had significantly lower subfoveal (64.0 vs 63.5, p=0.021) and average CVI (63.5 vs 63.1, p=0.021). No difference in temporal and nasal CVI.
COVID-19 results in significantly thicker choroid with reduced relative vascularity (CVI). This may be attributable to increased vascular permeability secondary to inflammation, resulting in exudation into choroidal stroma. Future longitudinal studies are required to evaluate for long term visual sequalae and whether these choroidal changes are permanent.