Barrier function in the ocular surface: from conventional paradigms to new opportunities

Area of Science:

• Ophthalmology
• Cell Biology
• Immunology

Background:

• The ocular surface acts as a critical physical and immunological barrier, protecting the eye.
• Its barrier function maintains corneal hydration and transparency, essential for vision.
• Dysfunction of this barrier is linked to various ocular diseases, including dry eye and infectious keratitis.

Purpose of the Study:

• To review the components of the ocular surface epithelial barrier, including transcellular and paracellular pathways.
• To describe methodologies for measuring ocular surface barrier function in vitro, animal models, and clinical studies.
• To discuss recent findings on the regulation of tight junction proteins and potential therapeutic interventions.

Main Methods:

• Review of existing literature on ocular surface barrier components and function.
• Description of in vitro, animal, and clinical study methodologies for barrier assessment.
• Analysis of studies on tight junction proteins (occludins, zonula occludens, claudins).

Main Results:

• Detailed examination of transcellular and paracellular pathways constituting the epithelial barrier.
• Evaluation of the utility and limitations of various barrier function measurement techniques.
• Overview of recent research on the regulation of key tight junction proteins.

Conclusions:

• A comprehensive understanding of the ocular surface barrier is crucial for diagnosing and treating related diseases.
• Methodologies for assessing barrier function vary in applicability and limitations.
• Knowledge of tight junction protein regulation offers potential avenues for therapeutic strategies.