To assess the effect of severe acute respiratory syndrome coronavirus-2 infection on the conjunctiva and tear film.
Thirty-eight patients with confirmed COVID-19 and 31 healthy controls were included in this prospective and observational study. Individuals with COVID-19 formed the patient group, and healthy individuals formed the control group. Conjunctival impression cytology (CIC), TBUT, Schirmer II test, and ocular surface disease index were evaluated in all participants.
No significant difference was observed regarding the mean age and gender between the groups (P=0.786 and P=0.122, respectively). The mean TBUT and Schirmer II test results did not differ between the two groups (P=0.496 and P=0.447, respectively). The CIC results revealed decreased density and cell size of goblet cells and moderate to high enlargement, squamous changes, and increased nucleocytoplasmic ratio in nongoblet epithelial cells in the COVID-19 group compared with the control group. Based on the Nelson classification in CIC samples, 60.6% of the COVID-19 group and 19.4% of the control group had changes consistent with grade 2 or above. The presence of neutrophils in CIC was significantly higher in the COVID-19 group (P<0.001), whereas the presence of lymphocyte was similar between the two groups (P=0.247).
This study revealed the pathological conjunctival alterations in patients with COVID-19 and demonstrated that pathological ocular surface alterations may present even at the beginning of COVID-19 without clinically significant ocular manifestation.