A: Diagram of the stimulus array used to elicit the mfERGs. A: Diagram of the stimulus array used to elicit the mfERGs. The stimulus consisted of 103 hexagons, organized in 6 concentric rings, scaled (not represented) to elicit similar amplitudes at all locations. B: Superimposition of the mfERG stimulus array and the SD-OCT (GCL+IPL) elliptical annulus grid (blue) on a fundus image, centered on the fovea. The green-contoured hexagon represents the central mfERG hexagon, and the two gray circles represent the 10° and 20° of the mfERG grid. Ana Rita Santos et al. Diabetes 2017;66:2503-2510 ©2017 by American Diabetes Association