Figure 1: Mean waveforms obtained under the melanopsin (top left), rod (lower left), and cone (lower right) paradigms stratified by subject group.

The upper right panel shows responses measured with a long wavelength flash (450 cd/m²) presented in the dark, for comparison to the melanopsin-mediated condition. The long wavelength 450 cd/m² flash is not typically included in the standard set of conditions (rod, cone, melanopsin) and data from this condition will not be considered further. The red traces represent the mean waveform for the moderate-severe NPDR group, the green traces represent the mean waveform for the mild NPDR group, the blue traces represent the mean waveform for the no NPDR group, and the black traces represent the mean waveform for the control group. The vertical dashed lines in the top panels indicate the range over which the melanopsin-mediated (sustained) amplitude was measured. The stimulus onset and offset are represented by the boxes along the x-axes.