Figure 18. Strain differences in solidity. The solidity of RPE cells in three genotypes, one wild type (WT), C57Bl/6J, and two models of retinal degeneration, IRBP^−/− and rd8, at postnatal day (P)30 and P720. Group sizes were four to five animals for each genotype at P30 and three animals at each genotype at P720. At P30, neither the IRBP^−/− nor the rd8 differed significantly in cell solidity from the WT. However, at P720, RPE cells of the rd8 were significantly less solid than those of the rd8 at P30 and the WT at P720.