DKK1 and retinal ischemia: It is hypothesized that paeoniflorin may protect against retinal ischemia through its neuroprotective and antioxidative, and anti-inflammatory effects via the downregulation of pro-angiogenic β-catenin, HIF-1α, VEGF, and inflammatory Ang-2 biomarkers with similar effectiveness to Wnt/β-catenin inhibitor dickkopf-related protein 1 (DKK1), anti-angiogenic PEDF, and anti-VEGF therapy.