Figure 6.

(a–c) White arrows: typical interimage incongruencies for three twin pairs with feature 23, representing the area covered by drusen, and the intertwin incongruency for feature 23 between the individuals in each twin pair. (a) MZ twin pair with similar feature 23 (drusen area) values for all four eyes, and an intertwin incongruency of 0.977; (b) DZ twin pair had a larger feature 23 for both eyes of individual A than for individual B, but contralateral eyes for each individual had similar values and an intertwin incongruency of 1.68; (c) DZ twin pair with drusen in both eyes of individual A but not in those of individual B and an intertwin incongruency of 6.26 with respect to this feature.