Corneal epithelium and stroma

The corneal epithelium and stroma are the primary structural and functional layers of the anterior eye. The corneal epithelium is a non-keratinized stratified squamous layer that serves as a critical physical and immunological barrier, preventing the entry of pathogens and maintaining a smooth surface for the tear film to ensure proper light refraction (StatPearls, 2023). Beneath the epithelium and its basement membrane lies the corneal stroma, which accounts for approximately 90% of the total corneal thickness. The stroma is composed of a highly organized extracellular matrix of type I collagen fibrils and specialized fibroblasts called keratocytes, which are essential for maintaining corneal transparency and mechanical strength (NIH, 2022). While these layers are the site of various ocular pathologies and the destination for topical drug delivery, they represent anatomical compartments containing diverse molecular structures rather than a single therapeutic target. Clinical interventions often focus on preserving the integrity of these layers, such as using riboflavin-mediated collagen cross-linking to stabilize the stroma in keratoconus or using anti-inflammatory agents to protect the epithelium in chronic dry eye disease (PubMed, PMID: 25703474).

Other names

Corneal layersAnterior corneal tissueCorneal parenchyma

Not applicable as these are anatomical tissue layers rather than a specific molecular target. Drugs interacting with these layers typically target specific receptors (e.g., integrins), enzymes, or metabolic pathways within the resident cells (keratocytes and epithelial cells) or modify the extracellular matrix (e.g., collagen cross-linking).