fig2

Figure 2. The vicious cycle in the pathogenesis of dry eye disease. CNFD: Corneal nerve fiber density; CNFL: corneal nerve fiber length; DED: dry eye disease; ER: endoplasmic reticulum; IL-20: interleukin 20; IL-1β: interleukin-1beta; MAPKs: mitogen-activated protein kinases; MMPs: matrix metalloproteinases; NF-κB: nuclear factor kappa-light-chain-enhancer of activated B cells; THO: tear hyperosmolarity; TLRs: Toll-like receptors; TNF-α: tumor necrosis factor alpha; TRPV1: transient receptor potential vanilloid 1.