Additionally, the plasma ET-1 level of patients with glaucoma correlated significantly with reduced superior RNFL thickness (p = 0.049 Table 2), while no correlation was found with reduced inferior RNFL thickness (Table 2), nor between AqH ET-1 level and superior/inferior RNFL thickness loss (Table 2, Supplemental Table 3). This evidence concerns the gene EDN1 and glaucoma.