These findings include: (i) Th1 cells undergo functional reprogramming in the early phase of glaucoma, enabling them to target the retina; (ii) infiltrated Th1 cells fostered a pro-inflammatory milieu through intricate interplay with retinal microglia, thus leading to RGC loss; (iii) retinal endothelial cells were affected by peripheral Th1 cells and upregulated VCAM-1 expression in glaucomatous mice, in turn facilitating Th1 cell invasion. Here, VCAM1 is linked to glaucoma.