Analysis of Retinol Binding Protein 4 and Gene Variation in Non-Neovascular Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) may be associated with variants and is characterized by the accumulation of visual cycle-byproduct lipofuscin. Reducing retinol-binding protein 4 (RBP4), a retinol transporter protein, may reduce lipofuscin production. This study aims to assess the associations between plasma RBP4, the variation, and AMD severity. Sixty-seven participants were grouped into healthy/mild AMD ( = 32) and severe AMD ( = 35) groups. The latter group was older than the former group and had higher levels of RBP4 (36.8 ± 8.3 vs. 30.4 ± 7.0 μg/mL, = 0.0012). The ten participants with six linked-variants had higher RBP4 than those without (37.8 ± 7.7 vs. 32.4 ± 7.9 μg/mL; = 0.026), and eight of them had severe AMD. Univariate analyses showed that severe AMD was related to older age (OR, 1.26; 95% CI, 1.13-1.40; < 0.0001) and to higher RBP4 levels (OR, 1.12; 95% CI, 1.04-1.20; = 0.003), whereas the linked variants had no associations. After adjustment, however, only age remained significantly associated with severe AMD. This pilot study shows a trend of higher plasma RBP4 levels in severe AMD or the -linked variants, and further age-matched studies are warranted.