Figure 2. Change of oxidative stress and antioxidant enzymes in cultured GO orbital fibroblasts in response to exogenous H₂O₂ . After treatment of orbital fibroblasts with 200 μM H₂O₂, the amplitude of increase in H₂O₂ and Mn-SOD activity and the amplitude of decrease in catalase activity, GPx activity, and GSH/GSSG ratio were exacerbated in GO fibroblasts as compared with controls.