Relationship between uveitis and the differential reactivity of retinal microglia.

Uveitis, a complicated group of ocular inflammatory diseases, can be affected by massive pathogenic contributors such as infection, autoimmunity and genetics. Although it is well known that many pathological changes, including disorders of the immune system and disruption of the blood retinal barrier, count much in the onset and progression of uveitis, there is a paucity of safe and effective treatments, which has exceedingly hindered the appropriate treatment of uveitis. As innate immune cells in the retina, microglia occupy a salient position in retinal homeostasis. Many studies have reported the activation of microglia in uveitis and the mitigation of uveitis by interfering with microglial reactivity, which strongly implicates microglia as a therapeutic target. However, it has been increasingly recognized that microglia are a nonhomogeneous population under different physiological and pathological conditions, which makes it essential to thoroughly have a knowledge of their specific characteristics. The paper outlines the various properties of activated microglia in uveitis, summarizes the connections between their polarization patterns and the manifestations of uveitis, and ultimately is intended to enhance the understanding of microglial versatility and expedite the exploration of promising strategies for visual protection.