How much can the eyes reveal about a person? A first-of-its-kind study from Northwestern Medicine and published in the Journal of Imaging is giving experts an idea how long COVID affects the body by looking through the eyes. The research could help doctors diagnose and track how the condition impacts people over time and provide insight into the cause of long COVID.

In the study, researchers used advanced imaging techniques to examine the retinas of non-hospitalized long COVID patients from the Northwestern Medicine Neuro COVID-19 Clinic and found that patients with long COVID experienced a significant reduction in the density of blood vessels in the back of the eye, compared to healthy individuals.

“This finding bridges gaps between ophthalmology, neurology, and COVID-19, helping us better understand how inflammation affects different organs in the body,” said Manjot K. Gill, MD, senior author of the study and ophthalmology lead of the Northwestern Medicine Comprehensive COVID-19 Center. “The change in blood vessels in the deep part of the retina supports the hypothesis that long COVID affects similar blood vessels in other parts of the body, like the brain, which can potentially contribute to the symptoms of long COVID such as memory loss, brain fog and fatigue.”