Figure 4. Amplitude (AP1-N2) of flash visual evoked potential (F-VEP) before and after optic nerve injury. The AP1-N2 obviously decreased immediately after the optic nerve injury, and was then restored very slowly. At 2 weeks, the AP1-N2 of the OEC+GDNF group were obviously restored compared with the Control, OEC, and GDNF groups. At 4 weeks and 8 weeks after injury, the AP1-N2 of the OEC+GDNF, OEC, and GDNF groups increased significantly compared to the Control group. #: p<0.01 versus Control group; *: p<0.05 versus Control group. Data were shown as mean±SD (n=5).