FIGURE 2.

Impact of shear stress. The flow of the tear film and aqueous humor potentially results in shear stress on the anterior and posterior surfaces of the cornea and predominantly affects the epithelium and endothelium of the cornea. For corneal epithelial cells (CEpCs), steady flow maintains limbal epithelial stem cell (LESC) stemness, whereas intermittent flow induces their differentiation. Shear stress is crucial for spontaneous renewal and exfoliation of superficial epithelial cells, while it also promotes cell–cell contacts to strengthen barrier function. In the wound healing process, shear stress can mediate migration of CEpCs to facilitate wound healing, while suppressing proliferation of CEpCs to delay wound repair. Corneal endothelial cells (CEnCs) are more likely to be detached from the corneal endothelium with higher shear stress (>0.1 dyn/cm²). Also, the expressions of the corneal endothelium-related markers, such as ZO-1, N-cadherin, and Na⁺-K⁺-ATPase, could be upregulated with shear stress in a dose-dependent manner.