<i>In vivo</i> C57BL/6 mouse models of A. fumigatus keratitis, the effects of isoimperatorin on inflammatory signaling, neutrophil infiltration, macrophage polarization, and cell apoptosis were assessed using quantitative real-time polymerase chain reaction (qRT-PCR), western blotting and immunofluorescence.<h4>Results</h4>Isoimperatorin inhibited TLR4/MyD88 complex formation and IKK/NF-κB phosphorylation, downregulated pro-inflammatory cytokines, reduced neutrophil infiltration, and promoted macrophage polarization from the M1 to the M2 phenotype. Here, TLR4 is linked to keratitis.