According to a new study in mice by scientists at the National Eye Institute (NEI), immune cells called microglia can completely repopulate in the retina after being nearly eliminated. Cells also exhibit their normal organization and functioning. Findings point to potential therapies to control inflammation and slow the progression of rare retinal diseases such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD), the most common cause of blindness in Americans 50 years and over.