Figure 2.

Box plots illustrating group differences in arteriole-to-venule ratio (AVR), mean fractal dimension (mean-D), and tortuosity index (TI) of the retinal vessels. Both AVR and mean-D of the subjects with hypertensive retinopathy (HR) (a) or CADASIL (b) were lower than age- and gender-matched controls. The increment of TI was significant in HR and uncertain in CADASIL group. Statistically significant differences between the groups are indicated as ∗ for P values ≤ 0.05 and as ∗∗ for P values ≤ 0.01. The boxes include data between 25th and 75th percentiles. Horizontal line in the box represents the median. The whiskers indicate the minimum and maximum values.