A) Retinal sections from mice of the C1qtnf5 wild-type, Ser163 Arg heterozygous (Het) and homozygous (Mut) genotypes at the ages indicated, stained and examined by light microscopy. B) Ultrastructures of the basal site of the RPE and Bruch's membrane of retinas from wild-type (Wt) and C1qtnf5 Ser163Arg KI (Het, Mut) mice at the ages of 6 months and 20 months, respectively. C) The thickness of Bruch's membrane increased with age (Pearson correlation Wt: n = 6, p = 0.103, r2 = 0.526; Het: n = 22, p = 0.0005, r2 = 0.459; Mut: n = 21, p = 0.0039, r2 = 0.362) but no significant difference between wild-type and C1qtnf5 Ser163Arg KI mice was found.