GDF15 and open-angle glaucoma: To explore a plausible relationship between the levels of AH GDF15 and disease severity of glaucoma, we sub-classified glaucoma patients from the smaller cohort described above (Table S1) into mild (n = 10), moderate (n = 8), and severe (n = 20) POAG subgroups, based on the ICD-10 coding of each patient.