The cornea is a transparent tissue with significant refractive and barrier functions. Corneal epithelium constitutes the first line of defense against foreign pathogens. Corneal epithelial cells interact to form a functionally selective permeability barrier. Dysfunction of this barrier leads to corneal impairment followed by a series of ocular surface diseases and even blindness. Tight junctions (TJ), located at the top of the intercellular space of corneal epithelial superficial cells, play a critical role in establishing and maintaining the barrier function. Previous studies have shown that destruction of the TJ acts as a crucial step of the occurrence and progression of multiple ocular surface diseases. Understanding the fundamental features and functions of the TJ, noticing the risk factors of TJ disruption, and clarifying the key role of TJ in the pathogenesis of various ocular surface diseases will help to better understand and treat ocular surface diseases.

Epithelium, corneal; Tight junctions; Corneal diseases