The Role of Insulin-like Growth Factor (IGF) System in the Corneal Epithelium Homeostasis—From Limbal Epithelial Stem Cells to Therapeutic Applications.

Simple Summary: The corneal epithelium is a protective barrier and refractive structure in the eye maintained through a complex regenerative process involving the lacrimal gland, tear film, and corneal nerves. This review explores the insulin-like growth factor (IGF) system and its role in corneal epithelium homeostasis. Emphasis is placed on the significance of limbal epithelial stem cells and potential therapeutic applications targeting the system components. The corneal epithelium, comprising three layers of cells, represents the outermost portion of the eye and functions as a vital protective barrier while concurrently serving as a critical refractive structure. Maintaining its homeostasis involves a complex regenerative process facilitated by the functions of the lacrimal gland, tear film, and corneal nerves. Crucially, limbal epithelial stem cells located in the limbus (transitional zone between the cornea and the conjunctiva) are instrumental for the corneal epithelium integrity by replenishing and renewing cells. Re-epithelialization failure results in persistent defects, often associated with various ocular conditions including diabetic keratopathy. The insulin-like growth factor (IGF) system is a sophisticated network of insulin and other proteins essential for numerous physiological processes. This review examines its role in maintaining the corneal epithelium homeostasis, with a special focus on the interplay with corneal limbal stem cells and the potential therapeutic applications of the system components. [ABSTRACT FROM AUTHOR]