Corneal epithelial basement membrane

The corneal epithelial basement membrane is a specialized extracellular matrix between basal epithelial cells and the corneal stroma, composed principally of collagens, laminins, heparan sulfate proteoglycans (e.g., perlecan), and nidogens, with other components such as thrombospondin-1, matrilin-2/4, and sometimes fibronectin[1][3]. It anchors epithelium to stroma, supports epithelial migration and differentiation, and functions as a selective barrier and growth-factor reservoir that shapes homeostasis and wound healing[1][3]. Defective regeneration after injury allows epithelial- and tear-derived TGF-β and PDGF to persist in the stroma, driving myofibroblast development and corneal fibrosis/haze until the BM is fully restored and profibrotic signaling abates[3]. An intact BM also limits microbial translocation; disruption by injury or bacterial proteases facilitates penetration in infections such as Pseudomonas keratitis[4]. Epithelial reattachment involves reassembly of hemidesmosomes and anchoring fibrils; if the BM is damaged, firm adhesion can take months to re-establish[2].

Other names

Corneal epithelial basement membrane (EBM)Corneal basement membraneEpithelial basement membrane of the corneaOcular surface epithelial basement membraneBasement membrane of corneal epithelium

Restoration of BM integrity reduces stromal penetration of TGF-β/PDGF, depriving myofibroblasts of profibrotic cues and promoting apoptosis, which clears haze[3] Maintaining an intact BM provides a physical size-exclusion and matrix barrier that reduces microbial translocation across epithelium[4]