OPN4 and Alzheimer disease: Likelihood-ratio test showed the existence of interaction age × group for melanopsin-mediated PIPRBlue (Alzheimer’s group: β = -0.0042; 95% CI = -0.0073–0.0011; r = -0.5) and transient peak amplitude (Alzheimer’s group, blue flash: β = -0.0034; 95% CI = -0.0055–0.0014; r = -0.59; red flash: β = -0.0021; 95% CI = -0.0039–0.0003; r = -0.44) parameters with a significant correlation only in AD (Supplementary Tables 2, 3 and Supplementary Figures 1B,D,F).