Corneal Cellular and Neuroinflammatory Changes After SARS-CoV-2 Infection

The purpose of this study was to evaluate corneal cellular and ultrastructural changes and to quantify the neuroinflammatory process in patients after mild severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Thirty patients after SARS-CoV-2 infection and 41 age-matched controls were examined. All subjects underwent in vivo confocal microscopy of the corneal cell layers and subbasal nerve fibers with the Heidelberg Retina Tomograph II. Semiautomated analysis of basal epithelial, anterior and posterior stromal keratocyte, and endothelial cell density was performed. Dendritic cell (DC) density and area were also calculated, and subbasal nerve plexus morphology was analyzed.

The posterior stromal keratocyte density was significantly lower in patients after SARS-CoV-2 infection ( P = 0.0006). DC density in the central cornea was significantly higher in patients after SARS-CoV-2 infection ( P = 0.0004). There was a significant difference in the DC area between the 2 groups ( P < 0.0001). Significantly altered subbasal nerve fiber morphology was detected in patients after SARS-CoV-2 infection compared with healthy volunteers ( P < 0.05).

Corneal cellular and ultrastructural changes demonstrated in this study suggest neuroinflammatory consequences of COVID-19 in the cornea in the absence of ophthalmoscopic alterations.