Clinical Report: Optic Nerve Head and Macular Perfusion Changes Pre- and Post-COVID-19

Overview

This longitudinal study evaluated optic nerve head (ONH) and macular vessel density (VD) changes before and after COVID-19 infection using optical coherence tomography angiography (OCTA) in 20 patients. Significant reductions in ONH-VD and radial peripapillary capillary VD (RPC-VD) were observed post-infection, indicating microvascular impairment associated with COVID-19.

Background

COVID-19, caused by SARS-CoV-2, primarily affects the respiratory system but also induces systemic endothelial inflammation and microvascular dysfunction. The virus can infect ocular tissues expressing ACE2 receptors, leading to retinal microvascular changes such as cotton wool spots and microhemorrhages. OCTA is a non-invasive imaging modality that quantifies retinal microvasculature, enabling detection of early microvascular alterations. Prior studies compared COVID-19 patients to controls, but this study uniquely assesses microcirculatory changes longitudinally in the same individuals before and after infection.

Data Highlights

Key Findings

• Significant reductions in optic nerve head vessel density (ONH-VD) were observed in multiple sectors including whole image, inside disc, peripapillary, nasal, inferonasal, inferotemporal, superotemporal, and temporal areas post-COVID-19 (p-values ranging from <0.001 to 0.004).
• Radial peripapillary capillary vessel density (RPC-VD) significantly decreased in most sectors except inside the disc, superonasal, and temporal regions after COVID-19 infection.
• The study utilized a longitudinal within-subject design, comparing OCTA measurements before and after COVID-19 in the same patients, enhancing the reliability of observed microvascular changes.
• OCTA imaging was performed with strict quality control, including exclusion of images with low signal strength or motion artifacts, ensuring data accuracy.
• The mean time since COVID-19 diagnosis was approximately 37 days, with recovery confirmed by negative PCR tests about 22 days prior to post-infection imaging.

Clinical Implications

These findings suggest that COVID-19 induces measurable microvascular impairment in the optic nerve head and peripapillary retina, detectable by OCTA. Clinicians should consider ocular microvascular evaluation in patients recovering from COVID-19, especially those with visual symptoms, as these changes may reflect systemic endothelial dysfunction. OCTA may serve as a useful tool for monitoring microvascular sequelae post-infection.

Conclusion

This study demonstrates significant reductions in optic nerve head and radial peripapillary capillary vessel densities following COVID-19 infection, highlighting the virus’s impact on ocular microcirculation. Longitudinal OCTA assessment provides valuable insights into COVID-19–related microvascular alterations.

References

1. SARS-CoV-2 and COVID-19 Pathophysiology -- Viral Entry and Endothelial Dysfunction
2. OCTA in Retinal Microvascular Assessment -- Imaging Techniques and Clinical Applications
3. COVID-19 Ocular Manifestations -- Retinal Findings and Vascular Complications
4. Longitudinal OCTA Studies in COVID-19 -- Microvascular Changes Pre- and Post-Infection