Researchers are investigating if the COVID virus can affect an infected person's vision and depth perception. The study is co-led by Griffith University's Menzies Health Institute and South Korea's Center for Convergent Research for Emerging Virus Infection, Korea Research Institute of Chemical Technology.
The findings were published in Nature Communications.
The researchers discovered that SARS-CoV-2 can infect the eye through the respiratory system, via the brain, and that the trigeminal nerves are vulnerable to the virus.
Prof. Suresh Mahalingam, principal investigator and co-author of the study, explained that the virus can start impairing vision when the retina thickens due to inflammation of the optic nerves, abnormal fluid buildup, and immune cell infiltration.
"The virus can infect the eye through nerve tissues at the back of the eye that play a role in the visual aspects of the eye and sending signals for visual purposes. The result of this retinal inflammation was a reduction in depth perception due to blurred vision," Prof Mahalingam said.
It appears that the blurred vision is merely a symptom and not the result of long-term eye tissue deterioration. Additionally, only a very tiny number of persons are expected to be impacted.
Mr. Ng Wern Hann, a Ph.D. candidate at Griffith University, noted that while much COVID research has concentrated on respiratory illness, particularly in the lungs and nasal region, little attention has been paid to the eyes.
"We found the virus can indeed infect the eye through a normal intranasal approach, but also if droplets of the virus make direct contact with the eye. The ACE2 receptor is what the virus attaches to in order to infect a particular cell in a tissue or organ, and this receptor is found in abundance in the lungs, tonsils, nasal cavity, kidneys and heart, which is why a lot of reports have been published for those organs, but we found ACE2 receptors are also present in the eye, therefore facilitating infection,” he explained.