Figure 4

Heatmap of Pearson’s correlation coefficients between all possible combinations of variables, which were adjusted by multiple regression with the explanatory variables in Table 1, in the diffractive bifocal IOL group. The asterisk * in this figure indicates a significant correlation between two parameters at p < 0.00002 after Bonferroni’s correction. The t test (two-sided) was applied to evaluate the significance of differences between the two groups. The sample size for each parameter is shown in Supplementary Table 3(C). The illustration was performed using a commercially available software program (R, version 3.6.1; R Core Team, 2019, Vienna, Austria.)³⁸ (https://cran.r-project.org/web/packages/pheatmap/pheatmap.pdf).