Recurrent uveitis [you-vee-EYE-tus] is a leading cause of blindness in horses. It involves repeated inflammation of the uvea [YOU-vee-uh], the pigmented layer of the eye.

In cases of equine autoimmune uveitis, a horse’s own immune system damages structures inside the eye and blocks light from the retina. In advanced cases, the damage is irreversible, but if caught early, treatment may save a horse’s sight.

Uveitis is typically treated with corticosteroids, but their long-term use is fraught with side effects. Now, University of Florida researchers are studying a topical drug that reduces inflammation through a completely different mechanism. So far, it has been shown to improve the eyesight in several severely affected horses. The next step is a larger clinical trial.