This study reports the first characterization of the intracellular proteome of peripheral blood mononuclear cells (PBMC) isolated from subjects diagnosed with primary open angle glaucoma (POAG)by shot-gun proteomics. Glaucoma is a chronic optic neuropathy and among the first causes of irreversible blindness on a global scale. Several recent data have pointed out alterations of immune system processes in glaucoma subjects. Very recently, oxygen consumption rate (OCR) and NAD levels have been proposed as biomarkers of disease severity.