Effects of MSC-HO-1 on retinal histology at 21 days after I/R injury. (a) Representative retinal section images of control, I/R + PBS, I/R + MSC, or I/R + MSC-HO-1 group were achieved by H&E-staining. (b) The thickness of total retina (from the inner limiting membrane to the pigment epithelium), the inner plexiform layer (IPL), the inner nuclear layer (INL), and the outer nuclear layers (ONL) was investigated in the eyes of control, I/R + PBS, I/R + MSC, or I/R + MSC-HO-1 group, respectively (n = 5). aaP < 0.01 compared with control group; bbP < 0.01 compared with IR + PBS group; ccP < 0.01 compared with IR + MSC group; cP < 0.05 compared with IR + MSC group.