A cross-sectional comparative analysis of corneal endothelial parameters by specular microscopy in post covid versus normal population in Western India

Abstract

Objective: To observe the changes in corneal endothelium post COVID-19 infection in different age groups using specular microscopy and compare it with the normal population in western India during the pandemic. Materials and Method: 129 patients COVID-19 recovered, and 123 age-matched healthy controls were included in this cross sectional, comparative, monocentric study. Corneal endothelial parameters like Cell Density (CD) (cell/mm2), Coefficient of Variation (CV) (polymegathism, %), Cell hexagonality (polymorphism, %), Average cell area (MCA) (μm2/cell), and mean value of Central Corneal Thickness (CCT) (μm) were evaluated with a non-contact specular microscope (TOMEY EM-4000, CBD.TOMEY USA) Results: The mean (SD) time since COVID diagnosis (months) in the study group was 6.67 (1.94). The mean (SD) time since RT-PCR negative (months) in the study group was 6.34 (1.74). The mean (SD) of CV (%) in the study group was (RE) 37.75 (6.03), (LE) 36.25 (4.66) and in control group was (RE) 35.23 (3.75), (LE) 34.77 (3.64). The mean (SD) of hexagonality (%) in the study group was (RE) 47.33 (6.84), 48.45 (7.33) and in control group was (RE):56.73 (4.13), (LE) 56.21 (5.34). Conclusion: The specular microscopic examination on the COVID-19 recovered patients revealed a decrease in the hexagonality of the endothelial cells (pleomorphism) and an increase in the cell size (polymegathism). Specular microscopic examination can be done to assess such earliest changes in corneal endothelium to evaluate the effects of the infection following recovery on ocular tissue to avoid long term sequalae.

Comparison of anterior segment parameters, corneal endothelial cell density, and coefficient of variation in COVID-19 and healthy groups

“…These ndings were in line with those of [20]. In the current study, the central corneal thickness increased in affected individuals compared to healthy individuals, and the number of HEX cells decreased in affected individuals, which was also consistent with the ndings of other researchers [15][16][17].…”

“…Furthermore, Kaushik et al performed a study on 129 patients recovered from COVID-19 disease and 123 healthy people as a control group. They reported a reduction in the corneal ECD and the number of HEX cells (pleomorphism) and an increase in the CV of cells (polymegatism) and the central corneal thickness[17].In a separate investigation, Elshalkami et al examined 64 right eyes of individuals who had recovered from COVID-19, along with 53 right eyes of healthy individuals as a control group. They found no signi cant difference in the evaluated parameters between the two groups, which could be attributed to improper grouping of the affected patients, inaccuracies in the timing of the examinations, or errors in the devices utilized for the research[18].Although contaminated droplets and bodily uids can readily infect the conjunctival epithelium, it remains uncertain whether COVID-19-related conjunctivitis stems from a primary eye infection or if it arises from the retrograde travel of viral particles from the upper tract to the nasolacrimal duct[19].…”