Optical Coherence Tomography (OCT) Findings in Post-COVID-19 Healthcare Workers

Abstract

Recent evidence suggests that SARS-CoV-2 may induce subtle anatomical changes in the retina, detectable through advanced imaging techniques. This retrospective case-control study utilized optical coherence tomography (OCT) to assess medium-term retinal alterations in 55 healthcare workers, including 25 individuals with PCR-confirmed COVID-19 and 30 non-COVID-19 controls, all of whom had worked in COVID-19 clinical settings. Comprehensive ophthalmological examinations, including OCT imaging, were conducted six months after infection. The analysis considered demographic variables, comorbidities, COVID-19 severity, risk factors, and treatments received. Central macular thickness (CMT) was significantly increased in the post-COVID-19 group (p < 0.05), with a weak but statistically significant positive correlation between CMT and disease severity (r = 0.245, p < 0.05), suggesting potential post-inflammatory retinal responses. No significant differences were observed in retinal nerve fiber layer (RNFL) or ganglion cell complex (GCL + IPL) thickness. However, mild negative trends in inferior RNFL and average GCL+IPL thickness may indicate early neurodegenerative changes. Notably, patients with comorbidities exhibited a significant reduction in superior and inferior RNFL thickness, pointing to possible long-term neurovascular impairment. These findings underscore the value of OCT imaging in identifying subclinical retinal alterations following COVID-19 and highlight the need for continued surveillance in recovered patients, particularly those with pre-existing systemic conditions.

Keywords: neurovascular imaging; optical coherence tomography; post-COVID-19 retinal changes.

Figure 1

Spectral-domainoptical coherence tomography(SD-OCT)of the macula (a) and optic nerve head (b) of a post-COVID-19 participant; a Zeiss Cirrus HD-OCT machine (Carl Zeiss Meditec AG, Germany) was used.

Figure 2

Box plot showing the distribution of central macular thickness (CMT) across COVID-19 severity levels. Although group-wise differences were not statistically significant, a separate correlation analysis revealed a statistically significant positive relationship between CMT and COVID-19 severity (r = 0.245, p = 0.02), suggesting that increased COVID-19 severity is associated with greater CMT.

Figure 3

(a) Box plot illustrating the distribution of inferior retinal nerve fiber layer (RNFL) thickness across COVID-19 severity levels. The median values appear slightly higher in the moderate group, but the interquartile overlap and broad data spread suggest no statistically significant difference across groups. A separate correlation analysis showed a weak negative association between inferior RNFL thickness and the COVID-19 severity score (r = −0.151), indicating a subtle trend toward thinning with increased disease severity.(b) Box plot of the distribution of the average ganglion cell layer + inner plexiform layer (GCL+IPL) thickness across COVID-19 severity levels. Median and mean values are marginally lower in the moderate group, but with overlapping distributions. Correlation analysis also revealed a slight negative trend between the average GCL+IPL thickness and the COVID-19 severity score (r = −0.176), though this trend was not statistically significant.