Imaging a healthy eye reveals that macrophages line the inner surface of the retina. They are sparse near the fovea and more densely packed farther from it, similar to nerve fiber bundles (not pictured) in the inner retina. Humans lose roughly two percent of these cells each year. As certain eye diseases progress, macrophages move to damaged areas, including near the fovea, and play a role in disease processes. One disease where this occurs is glaucoma, where drainage canals get blocked, increasing pressure and damaging the optic nerve.
Published in The Scientist magazine, March 2021. Writing by Ashley Yeager.