That is, M2-like microglia were activated only at the early stages of IOP elevation, while M1-like type microglia were sustainably activated during the whole period of IOP elevation (Figs. 5, 6), similar to the reports in mouse COH model, rd1 mouse model of retinal degeneration, and oxygen-induced retinopathy model [37, 48, 49]. This evidence concerns the gene PDE6B and retinal degeneration.