Collagen IV and laminin-1 as key macromolecules in ocular structure and pathology: A review.

The extracellular matrix (ECM), particularly the basement membrane (BM), is critical for the structural organization and functionality of ocular tissues. Among its core components, type IV collagen and laminin-1 play central roles in cell adhesion, polarity, differentiation, and survival. These macromolecules are ubiquitously expressed in the cornea, lens, retina, and optic nerve, forming tissue-specific BMs that support development and homeostasis. In this review, findings on the spatial distribution and molecular roles of collagen IV and laminin-1 in the eye under physiological and pathological conditions, are summarized. Mutations in COL4A1, COL4A2, and laminin-encoding genes (LAMA1, LAMB1, LAMC1) are associated with a range of ocular disorders, including anterior segment dysgenesis, lens dystrophy, optic nerve hypoplasia, and retinal abnormalities. Furthermore, autoimmune responses targeting these BM proteins have been implicated in systemic diseases such as rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, and Sjögren's syndrome, often leading to serious ocular complications. This review emphasizes the importance of ECM macromolecules in maintaining ocular integrity and highlights their potential as diagnostic biomarkers and therapeutic targets in both inherited and immune-mediated eye diseases.