In order to elucidate whether the mechanism underlying the protective effect of PGZ on diabetic mice is antihyperglycemic-dependent or not, we fed C57BL/6 mice with a regular diet without STZ and counted the Brn3A+ RGCs in the retinal whole mount of non-diabetic eyes harvested at 4 weeks after AION induction. The gene discussed is POU4F1; the disease is anterior ischemic optic neuropathy.