Assessment of corneal endothelial cell morphology and anterior segment parameters in COVID-19

Abstract

Background: The ocular manifestations of the 2019 novel coronavirus disease (COVID-19) vary from acute follicular, pseudomembranous, and hemorrhagic conjunctivitis to keratoconjunctivitis with subepithelial infiltrates and dendritic lesions. Similar to other respiratory viruses, such as adenoviruses, it is thought that COVID-19 may impact the cornea. However, its impact on the cornea and anterior segment parameters are currently poorly understood.

Objective: This study aims to assess the corneal endothelial cell morphology and anterior segment parameters in patients who have recovered from COVID-19.

Methods: In this cross-sectional study, the COVID-19 group comprised 34 patients who had been diagnosed with and recovered from COVID-19, while the control group comprised age- and sex-matched individuals without any systemic or ocular diseases. The endothelial cell density (ECD), coefficient of variation (CV) of cell area, hexagonal cell percentage (HEX), anterior chamber depth (ACD), central corneal thickness (CCT), horizontal anterior chamber diameter (HACD), iridocorneal angle (ICA), horizontal visible iris diameter (HVID), pupillary diameter (PD), and keratometry values (K1 and K2) were analyzed for each participant. The differences in each of these between the groups were analyzed using either an independent samples t test or a Mann-Whitney U test based on the normality of the data.

Results: Regarding corneal endothelial cell morphology, the ECDs for the COVID-19 and control groups were 2278.50 ± 186.78 cells/mm² and 2420.15 ± 222.25 cells/mm², respectively (p = 0.002). A significant increase was noted in CV values in the COVID-19 group compared with the control group (p < 0.001). The HEX values for the COVID-19 and control groups were 56.26 ± 5.75 and 61.50 ± 3.63, respectively (p < 0.001). Regarding the anterior segment parameters, no significant differences were observed between the groups (p > 0.05).

Conclusions: It was hypothesized that individuals who had recovered from COVID-19 would demonstrate a reduction in their endothelial functional preserves. A decrease in ECD and HEX and an increase in CV were observed in the individuals during their early post-recovery period from COVID-19.

Keywords: COVID-19; SARS-CoV-2; anterior segment; corneal endothelium; corneal topography.

Figure 1.

Flowchart for distribution of participants.

Figure 2.

Box plots showing corneal endothelial cell morphology differences under specular microscopy (ECD, CV, HEX, and CCT) between the control and COVID-19 groups. A reduction in endothelial functional preserves is seen in the COVID-19 group, with a decrease in both ECD and HEX and an increase in CV (p < 0.05). No significant difference was found in CCT between the groups (p > 0.05). Error bars represent a 95% confidence interval. Outliers are identified with a small circle for minor outlier values and a star for extreme outlier values.