RBP4 and age-related macular degeneration: The univariate analysis showed that a plasma RBP4 level of 36 μg/mL (OR, 8.13; 95% CI, 2.51–26.32; p = 0.0005) was better at differentiating between the healthy/mild AMD and severe AMD groups than 32 μg/mL (OR, 3.18; 95% CI, 1.17–8.70; p = 0.024), 33 μg/mL (OR, 4.22; 95% CI, 1.52–11.76; p = 0.006), 34 μg/mL (OR, 5.75; 95% CI, 1.99–16.67; p = 0.0012), or 35 μg/mL (OR, 6.06; 95% CI, 2.04–17.86; p = 0.0011).