According to a new study, some severe COVID-19 cases could be linked to eye damage.

The study published in the journal Radiology found that nine of the 129 French patients had an abnormal MRI of their eyeball.

The eyeball MRI showed that in the back part of the eye, one or more nodules.

Researchers added that eight of the nine patients battling COVID-19 spent time in the intensive care unit (ICU).

“We showed that a few patients with severe COVID-19 from the French COVID-19 cohort had one or several nodules of the posterior pole of the globe,” said study lead author Augustin Lecler, M.D., Ph.D., associate professor at the University of Paris and neuroradiologist from the Department of Neuroradiology at the Foundation Adolphe de Rothschild Hospital in Paris in a news release. “This is the first time these findings have been described using MRI.”

Researchers said that more research needs to be done but suggest that doctors consider scanning their patients dealing with COVID-19 for ocular issues.