EPO and Hyperglycemia: Hyperglycemia induces hypoxia in retinal tissue, which attracts growth factor (VEGF), erythropoietin (EPO), adhesion molecules [intercellular adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM-1)], cytokines [vascular adhesion protein (VAP-1)], and inflammatory genes [tumor necrosis factor-α (TNF-α), interleukin-1β (IL- 1β), and interleukin-8 (IL-8)].