MMP9 and Keratoconjunctivitis sicca: Dry eye disease is characterized by ocular inflammation; clinical studies have reported elevated levels of IL-1, IL-6, TNF-α, and TGF-β1 [26–28], along with MMP-9 in the tear film of dry eye patients [29, 30]. In vitro and in vivo studies on HCE cells and mouse corneal epithelium cells have shown increased expression of IL-6, IL-8, TNF-α, MMP's, and IL-8 levels on exposure to desiccation stress [31, 32].