Fig. 9.

Sustained riboflavin supplementation rescue of the functional and structural degenerations of the retina and the RPE. (A-C) Gradual improvements in scotopic-a wave (A) and b-wave (B) and in photopic b-wave (C) responses were observed in RDC mice switched back to RC at P240 for 30 (P270) and 60 (P300) days (RDC > RC group, grey). (D-F) Implicit time (D), OPL (E), and IPL (F) were measured from RC, RDC, and RDC > RC mice at P300. RDC > RC mice exhibit significant recovery in IPL thickness. (G) RPE flatmounts were stained for β-catenin (green). Flatmounts from RDC and RDC > RC groups both exhibited some cytoplasmic accumulation of β-catenin (green, arrowheads) as well as multinucleated enlarged RPE cells (asterisks). (H) RPE cell numbers were quantified from 6 regions each of a 0.0256 mm² window in any one of 3 independent samples and plotted from three independent animals per cohort. At P300, RDC mice have reduced number of RPE cells, but this is partially rescued in RDC > RC mice. One-way ANOVA (A-C, H) with Holm-Sidak post hoc comparison and two-way ANOVA with Bonferroni's post-hoc test (D) were used to evaluate the statistical significance between groups. In A-C differences at P240 were assessed by t-test since only two groups were present. (* = p < 0.05, ** = p < 0.01, *** = p < 0.001, **** = p < 0.0001). Graphs plot mean ± SEM. Number of samples for A-C, 4–10, each symbol represents the averaged value from one animal (two eyes). Number of samples for E-F, n = 3. OPL, Outer plexiform layer, IPL, inner plexiform layer. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)