Local ocular surface findings in COVID-19 patients without ocular symptoms

ABSTRACT Purpose: To investigate subjective ocular symptoms and objectively measure tear secretion in patients with a confirmed diagnosis of coronavirus disease-2019 (COVID-19). Methods: In this prospective cross-sectional study, 24 patients who had survived COVID-19 infection and 27 healthy controls were enrolled. Conjunctival impression cytology, the Schirmer test, tear-film break-up time, corneal staining scores were applied to all the participants. Results: No significant difference was noted with regard to the gender and mean age between the two groups (p=0.484 and p=0.599, respectively). The conjunctival impression cytology analysis revealed that the density of the goblet cells was decreased, while the counts of lymphocytes and neutrophils were increased in the COVID-19 group patients when compared with ethe control group patients. When the Nelson classification was applied to the conjunctival impression cytology samples, 25% of the COVID-19 group patients and 14.8% of the control group patients exhibited changes consistent with ≥grade 2. The mean tear-film break-up time, Schirmer test, and corneal staining score results were determined to differ between the COVID-19 and control groups (p=0.02, p<0.001, and p=0.003, respectively). Conclusions: The present study revealed the pathological conjunctival alterations of patients with a confirmed diagnosis of COVID-19, indicating the possibility of the occurrence of pathological ocular surface alterations to even at the end of COVID-19 infection, without the occurrence of any significant clinical ocular manifestations.