MMP9 and Corneal opacity: In conclusion, using alkali burn injury and LPS treatment as models of DAMP- and PAMP-induced sterile corneal inflammation, respectively, we found a pro-inflammatory role of the NLRP3 inflammasome in corneal inflammation, as evidenced by NLRP3-dependent development of corneal opacity, neutrophil infiltration, and up-regulation of IL-1β and MMP-9 expression.