Researchers find COVID-19 virus can breach blood-retinal-barrier

Systemic exposure – rather than direct transmission through the eye – sees the virus infect cells lining the blood-retinal-barrier

Two blue gloved hands are shown holding a white face mask

A new study from University of Missouri-Columbia researchers has determined that the virus which causes COVID-19 can enter the blood-retinal-barrier through systemic infection following inhalation – rather than ocular transmission.

Writing in PLOS Pathogens, scientists highlighted that due to the presence of viral RNA in corneal and conjunctival tissue, there has previously been speculation that the eye may act as a transmission route for COVID-19 infection.

However, experiments in mice found that ocular exposure to the virus that causes COVID-19 did not result in a lung infection or severe illness.

In contrast, exposure through nasal tissue resulted in the presence of the virus in ocular tissues as well as a hyperinflammatory response within the retina.

Researchers found that the extended presence of the virus that causes COVID-19 in the retina can cause retinal microaneurysm, retinal artery and vein occlusion, and vascular leakage.

Dr Pawan Kumar Singh, an assistant professor of ophthalmology at the University of Missouri School of Medicine, recommended that those who have been diagnosed with COVID-19 ask their eye care professional to check for signs of pathological change in the retina.

“Even those who were asymptomatic could suffer from damage in the eyes over time because of COVID-19 associated complications,” he said.