FSM protects diabetic rat retinal morphometric structure after 42-d treatment (72 d of total duration of diabetes). (a) The thickness of ILM & NFL; (b) the thickness of GCL + IPL; (c) the thickness of INL; (d) the thickness of OPL; (e) the thickness of ONL; (f) the thickness of RPE; (g) the thickness of EML + IS/OS; (h) the thickness of entire retina. ILM+NFL: internal limiting membrane and nerve fiber layer; GCL + IPL: ganglion cell layer and inner plexiform layer; INL: inner nuclear layer; OPL: outer plexiform layer; ONL: outer nuclear layer; RPE: retinal pigment epithelium; IS/OS + ELM: photoreceptor inner segment/outer segment and external limiting membrane. Values are presented as mean ± SD, n=8. ∗p < 0.05, ∗∗p < 0.01: untreated diabetic model group, CaD group, FSM high-dose, FSM medium-dose, and FSM low-dose group vs normal group; #p < 0.05, ##p < 0.01: CaD group, FSM high-dose, FSM medium-dose, and FSM low-dose group vs untreated diabetic model group.