Figure 2. The increased number of macrophages in the choroid was associated with the at-risk variants of the CFH Y402H polymorphism. The macrophages in the postmortem human eye sections were immunoreacted with CD68, a known marker for macrophages. The immunoreactivity for CD68 was developed with AEC (red) and counterstained with Mayer’s hematoxylin (blue; scale bar: 20 μm). A: A representative picture of CD68 immunoreactivity in the outer retina from a donor eye with the at-risk CC variant. B: A representative picture of CD68 immunoreactivity from a donor eye with the heterozygous CT variant. C: A representative picture of CD68 immunoreactivity from a donor eye with the protective TT variant. D: Negative control by primary antibody omission. E: The number of CD68-positive cells per 0.1 mm² choroid area differed significantly among donors with CC, CT, or TT variants of the CFH Y402H polymorphism (mean ± SEM, one-way ANOVA, p<0.05). There are more CD68-immunoreactive cells in the choroid of the CC eyes (3.44±0.77 per 0.1 mm², n=4) compared to the TT eyes (1.12±0.20 per 0.1 mm², n=6; post hoc Bonferroni multiple comparison test, *p<0.05).