Fig. 18. The foveal region in a flat-mounted adult human retina showing microglia labeled with an antibody to the human leucocyte antigen CD45. A. Labeled cells surround the fovea but are absent from the foveal pit (f), which lacks retinal blood vessels. Bar = 100 μm. B. At higher magnification, the stellate microglial cells surround the foveal rim. Bar = 20 μm. (Penfold PL, Provis JM: Antibodies to human leucocyte antigens indicate subpopulations of microglia in human retina. Vis Neurosci 7:383, 1991.)