RBP4 and age-related macular degeneration: Our study cohort also showed a similar trend consistent with these findings, with a higher proportion of metabolic syndrome (51%) and higher plasma RBP4 levels (36.8 μg/mL) found in the severe AMD group than in the healthy/mild AMD group, which had a lower metabolic syndrome prevalence of 28% and plasma RBP4 level of 30.4 μg/mL.