National Institutes of Health scientists studying the progression of inherited and infectious eye diseases that can cause blindness have found that microglia, a type of nervous system cell suspected to cause retinal damage, surprisingly had no damaging role during prion disease in mice. In contrast, the study findings indicated that microglia might delay disease progression.

The discovery could apply to studies of inherited photoreceptor degeneration diseases in people, known as retinitis pigmentosa. In retinitis pigmentosa cases, scientists find an influx of microglia near the photoreceptors, which led to the belief that microglia contribute to retina damage.