Macula. A, The normal macula is identified histologically by a thick, multilayered GCL and a central area of focal thinning, the foveola. Note the NFL (arrowhead) in the nasal macular region and the oblique orientation of Henle fiber layer (perifoveal OPL) (asterisk) . Clinically, the macula lies between the inferior and superior temporal vascular arcades. B, Spectral domain optical coherence tomography (SD-OCT) of the macula shows in vivo imaging with high-resolution details of the lamellar architecture of the retina. Note the NFL (arrowhead) in the nasal macular region, Henle fiber layer (asterisk), and the ELM (arrow). C, Higher magnification of the photomicrograph shown in part A and the SD-OCT image shown in part B illustrating the corresponding macular layers. D, SD-OCT image of the macula. NFL = nerve fiber layer; GCL = ganglion cell layer; IPL = inner plexiform layer; INL = inner nuclear layer; OPL = outer plexiform layer; ONL = outer nuclear layer; ELM = external limiting membrane; MZ = myoid zone; EZ = ellipsoid zone; OS = outer segments; IZ = interdigitation zone between outer segments and RPE; RPE/BM = retinal pigment epithelium/Bruch membrane; CC = choriocapillaris.