GNRH1 and keratoconus: Specifically, GnRH plasma concentration in both male and female KC subjects (67.3 ng/mL, IQR 53.4–89.8 ng/mL and 67.8 ng/mL, IQR 47.4–85.4 ng/mL, respectively) had lower GnRH plasma concentrations than sex-matched control subjects (159.9 ng/mL, IQR 80.0–202.0 ng/mL and 80.3 ng/mL, IQR 68.8–166.4 ng/mL, respectively, male p < 0.0001, female p = 0.0064, Figure 1B).