The Role of Decorin in the Ocular Surface: Structure, Function, and Therapeutic Potential

The ocular surface, comprising the cornea, conjunctiva, and sclera, relies on a complex extracellular matrix (ECM) for structural support and functional integrity. Decorin (DCN), a small leucine-rich proteoglycan, a key ECM component involved in collagen fibrillogenesis, growth factor modulation, and cellular regulation, is essential for maintaining corneal transparency, wound healing, and preventing pathological fibrosis. DCN interacts with various target molecules, including transforming growth factor-beta (TGF-β), vascular endothelial growth factor (VEGF), and epidermal growth factor receptor (EGFR), influencing critical processes, such as cell proliferation, inflammation, and angiogenesis. These interactions underscore DCN's therapeutic potential in ocular disorders like corneal scarring, pterygium, and keratoconus. This review explores the structure, expression, and functions of DCN in the ocular surface, emphasizing its regulatory mechanisms and therapeutic potential. Recent advancements include gene therapy approaches, sustained release systems, and topical applications, each demonstrating significant promise in treating ocular surface diseases. Additionally, the review highlights the importance of DCN in ocular disorders, including congenital stromal corneal dystrophy (CSCD), KC, and pterygium. This review aims to elucidate the multifaceted roles of DCN, paving the way for innovative therapeutic strategies in ocular surface therapy. Future directions for DCN research involve advanced delivery mechanisms, gene editing technologies, and expanded studies on other ocular surfaces.