The role of corneal epithelial thickness in ocular surface health

Abstract

Abstract The corneal epithelium (CE), which is made up of five to seven layers, is crucial for maintaining the integrity of the cornea and the health of the ocular surface. The present review delves into the importance of corneal epithelial thickness (CET) in the identification and treatment of a range of ocular surface diseases (OSDs), such as keratoconus (KCN), dry eye disease (DED), and the aftermath of refractive procedures. Spectral-domain optical coherence tomography (SD-OCT) can be used to provide reliable and precise CET values, providing valuable insights into epithelial remodeling patterns and their correlation with disease severity. In DED, CE irregularities correlate with clinical symptoms, revealing a distinctive thinning pattern in the superior epithelium, especially in severe cases. This is attributed to mechanical friction from frequent blinking. Contrasting studies on overall CET in DED patients highlight the need for standardized assessment protocols. In KCN, epithelial thickness mapping (ETM) demonstrates specific thinning patterns, aiding in early detection and management. Postrefractive surgery, epithelial remodeling contributes to residual refractive errors, emphasizing the epithelium’s role in compensating for stromal irregularities. This review underscores the importance of CET analysis in clinical practice, advocating for the integration of advanced imaging technologies like SD-OCT. Understanding the dynamic changes in CET can enhance early diagnosis, guide surgical decisions, and improve treatment outcomes for various OSDs, ultimately contributing to better ocular health maintenance.