EDN1 and open-angle glaucoma: The concentration of ET-1 was significantly higher in the aqueous humor from patients in the POAG (7.8 ± 5.1 pg/mL; p = 0.002) and NTG cohorts (6.1 ± 3.0 pg/mL; p = 0.030) compared to the control (4.0 ±1.9 pg/mL; two-tailed Welch’s t-Test).