EDN1 and glaucoma: It showed higher ET-1 levels for glaucoma patients by a pooled mean difference of 0.42 pg/mL of ET-1 (95% CI: 0.26–0.59, p < 0.001), after funnel plot evaluation and 8 outlier studies removals, with moderate heterogeneity among studies (I2 = 70%, p < 0.001) (Figure 2, Panel B).