Graphs showing morphometric differences between RPE subpopulations. (A–H) Morphometric data for each individual RPE cell in each of the five RPE subpopulations (P1 to P5) were collected using the REShAPE Selection Tool and quantified for cell area in square micrometers.(A), AR in arbitrary units 1 to 3 (C), hexagonality in arbitrary units 1 to 10 (E), and neighbors 1 to 14 (G) (box limits represent the first and third quartile, the central line shows the median and the whiskers indicate the 5th and 95th percentile). (B, D, F, and H) Corresponding statistical analysis of each RPE subpopulation and shape metric is presented as pairwise comparisons tables performed using Tukey test. (A linear mixed-effects model and a Tukey test for multiple comparisons were performed, n = 17; ***P < 0.001, **P < 0.01, *P < 0.05; SI Appendix, Tables S6–S9). (I–P) Shape-metric comparison of P4 with the three known macular populations—fovea, parafovea, and perifovea—and P2 for cell area (I), AR (K), hexagonality (M), and neighbors (O) (box limits represent the first and third quartile, the central line shows the median and the whiskers indicate the 5th and 95th percentile. ***P < 0.001). (J, L, N, and P) Corresponding statistical analysis of each RPE subpopulation and shape metric is presented as pairwise comparisons tables performed using Tukey test. (A linear mixed-effects model and a Tukey test for multiple comparisons were performed, n = 17; ***P < 0.001, **P < 0.01, *P < 0.05; SI Appendix, Tables S10 and S11). HSD, honest significant difference; ns, not significant.