Researchers have found that the virus responsible for COVID-19 has the ability to break through the protective blood-retinal barrier, which could have long-term effects on the eye. The blood-retinal barrier is meant to safeguard our vision by preventing microbial pathogens from reaching the retina and causing inflammation that could lead to vision loss. However, researchers at the University of Missouri School of Medicine have found that the COVID-19 virus can bypass this protective barrier, posing potential risks for the eye.Dr. Singh, a PhD and assistant professor of ophthalmology, is leading a research team aiming to find new ways to prevent and treat ocular infectious diseases. The team used a humanized ACE2 mice model and discovered that the virus responsible for COVID-19, SARS-CoV-2, can infect the interior of the eyes even if it doesn’t enter the body through the eye surface. Instead, they found that when the virus enters the body through inhalation, it not only infects organs such as the lungs but also reaches the eyes through the blood-retinal barrier by infecting the cells that line this barrier.
“This discovery is significant as we enhance our understanding of the virus’s behavior.Understanding the long-term effects of SARS-CoV-2 infection is crucial,” Singh stated. Previously, researchers focused on the virus’s impact on the ocular surface. However, our research shows that SARS-CoV-2 not only reaches the eye during systemic infection but also triggers an intense inflammatory response in the retina, leading to cell death in the blood-retinal barrier. The longer the virus remains in the eye, the greater the risk of damage to the retina and visual function.
Singh also found that prolonged presence of SARS-CoV-2 spike antigen can lead to retinal microaneurysm, retinal artery and vein occlusion, and vascular leakage.”
We suggest that individuals diagnosed with COVID-19 should consult their ophthalmologist to check for any potential changes to the retina,” Singh recommended. “Even those who did not show symptoms could experience eye damage over time due to COVID-19 complications.”
Prior research has shown that viruses and bacteria can breach the blood-retinal-barrier in immunocompromised individuals, but this study is the first to indicate that the virus responsible for COVID-19 might breach the barrier in otherwise healthy people, leading to an infection within the eye. This could be particularly concerning for immunocompromised patients or those with high risk.Untreated individuals with hypertension or diabetes may face more severe outcomes if they are not diagnosed with COVID-19 related eye symptoms. “Now that we are aware of the danger of COVID-19 to the retina, our objective is to gain a better understanding of the cellular and molecular mechanisms by which this virus penetrates the blood-retinal barrier and the resulting pathological effects, with the hope of influencing the creation of therapies to prevent and treat COVID-19 induced eye complications before a patient’s vision is affected,” Singh stated. The study, titled “SARS-CoV-2 infects cells lining the blood-retinal barrier and induces a hyperinflammatory immune response, aims to advance knowledge in this area.An article titled ”Novel Epithelial Insights Into The Mechanisms of Vesicular Stomatitis Virus Retinopathy” was recently published in PLOS Pathogens. The University of Missouri School of Medicine’s research team, which included Vaishnavi Balendiran, MD, Monu Monu, Faraz Ahmad, and Rachel M. Olson, PhD, Chief Scientific Officer, Laboratory for Infectious Disease Research at the College of Veterinary Medicine, conducted the study. The research was supported by funding from the University of Missouri and the National Institutes of Health (NIH)/National Eye Institute (NEI) grant R01EY032495.
