The crucial role of the blood-retinal barrier in guarding our eyesight from infections is well-documented. This barrier shields the retina from microbial pathogens that might instigate inflammatory responses leading to potential vision loss. However, a recent study from the University of Missouri School of Medicine uncovers a concerning discovery – the virus responsible for COVID-19 can infiltrate this protective retinal shield, potentially causing long-lasting impact on the eye.
The research was led by Pawan Kumar Singh, PhD, an assistant professor of ophthalmology. Singh and his team, who are innovating ways to prevent and treat ocular infectious diseases, have found that SARS-CoV-2, the virus that leads to COVID-19, can contaminate the interior of the eyes. This occurs not from the virus entering the body through the eyes, but through inhalation, leading to infection in organs like the lungs and eventually the eyes too, breaching the blood-retinal barrier.
Singh said, “Our research sheds light on the long-term effects of SARS-CoV-2 infection. Previously, the primary focus was on the virus’s exposure to the ocular surface. But our results show that SARS-CoV-2 reaches the eye during a systemic infection, triggering a hyperinflammatory response in the retina and causing cell death in the blood-retinal barrier. The longer the viral remnants stay in the eye, the risk of damage to the retina and visual function escalates.”
Singh’s team also found that the prolonged presence of SARS-CoV-2 spike antigen can lead to retinal microaneurysm, retinal artery and vein occlusion, and vascular leakage. Singh advises those diagnosed with COVID-19 to get their eyes examined for any signs of retinal changes. Asymptomatic individuals could also suffer eye damage over time due to COVID-19 related complications.
Though the blood-retinal barrier has been breached by viruses and bacteria in people with a compromised immune system, this research is the first to indicate that the COVID-19 virus could infiltrate the barrier in healthy individuals, resulting in an infection within the eye. Patients with compromised immunity or those with conditions like hypertension or diabetes could face worse outcomes if COVID-19 related ocular symptoms go unnoticed.
Singh added, “Now that we are aware of the risk COVID-19 poses to the retina, we aim to delve deeper into understanding the cellular and molecular mechanisms of how the virus breaches the blood-retinal barrier and its pathological implications. This knowledge could pave the way for developing therapies to prevent and treat COVID-19 induced eye complications before vision is jeopardized.”
This pioneering study titled “SARS-CoV-2 infects cells lining the blood-retinal barrier and induces a hyperinflammatory immune response in the retina via systemic exposure” was recently published in PLOS Pathogens. The research was supported by the University of Missouri and the National Institutes of Health (NIH)/National Eye Institute (NEI) grant R01EY032495.
Comments are closed for this post.