Which neuroglial cells are essentially modified macrophages found in the retina?

• A. Astrocytes
• B. Müller cells
• C. Microglia
• D. Oligodendrocytes

Answer: (C)

Microglia are the retina’s resident immune cells, functioning as the CNS’s macrophages. They continually survey the neural environment, phagocytose debris, and mount immune responses when injury or disease occurs. In the retina, they reside in the nerve fiber layer and synaptic layers where they help clear cellular waste and support synaptic health. This role distinguishes them from other retinal glia: astrocytes provide structural support and help maintain the blood-retina barrier, Müller cells span the retina to provide metabolic and structural support, and oligodendrocytes myelinate CNS axons rather than performing macrophage-like duties. So, microglia are the neuroglial cells that act as the retina’s macrophages.