Natural killer cells emerge as overlooked driver of wet macular degeneration

Age-related macular degeneration stands as the leading cause of irreversible central blindness in adults, yet current treatments address only the symptom: unchecked blood vessel growth in the retina. A cytokine analysis across a large population cohort now reveals the disease's root lies in a specific immunological imbalance—an altered peripheral natural killer (NK) cell population whose excessive activation drives neovascularization and vascular barrier collapse in the eye. Single-cell RNA sequencing maps the expansion of activated cytolytic NK cells within neovascular lesions, while human donor tissue shows these cells localized to malformed vessels, marked by terminal differentiation. The critical finding: adoptive transfer of pre-activated NK cells in wet macular degeneration models reduces neovascularization and restores vascular integrity. This discovery opens an unprecedented immunotherapy pathway, reframing age-related vision loss from mere symptom suppression toward correcting the immune mechanism that generates it.