Aqueous humor levels of RBP3 were significantly reduced from 5.26 ± 2.0 ng/mL in cataract patients to 4.05 ± 1.0 ng/mL (p = 0.009) in PEX patients; levels of RBP4 were reduced from 93.07 ± 61.95 ng/mL to 45.17 ± 22.27 ng/mL (p = 0.02), and levels of TTR were reduced from 10.11 ± 5.45 μg/mL to 5.68 ± 1.19 μg/mL (p = 0.01) (Figure 4A). Here, TTR is linked to cataract.