RBP4 and age-related macular degeneration: In the first multivariate model, age remained the only factor significantly associated with severe AMD (OR = 1.27; 95% CI, 1.13–1.44; p < 0.0001), whereas plasma RBP4 level (μg/mL) was no longer associated with severe AMD (OR = 1.06; 95% CI, 0.96–1.17; p = 0.26).