Inhouse Fabrication of a Reconstructed Human Corneal Epithelium Model for Use in Testing for Eye Irritation Potential

Introduction: In the last decade, a variety of in vitro eye irritation test (EIT) methods have been developed and validated as an alternative to animal testing to assess the ocular toxicity of chemicals. Among these in vitro test methods, that using reconstructed human corneal epithelium (RhCE) is considered to be most useful, but RhCE is expensive and cannot be purchased at any time in Japan. Thus, we undertook this study to establish a method for in house fabrication of RhCE using the immortalized human corneal epithelial cell lines. Materials and Methods: An RhCE fabricated from the immortalized human corneal epithelial cell line (iHCE-NY1) was evaluated in accordance with the performance standards of Test Guideline 492 issued by the Organization for Economic Cooperation and Development (OECD). Results: Histological analysis of the iHCE-NY1 model showed a complete corneal epithelium containing three corneal epithelial layers and the corneal epithelial marker, Mucin-16, was expressed in the appropriate regions. Prediction of eye irritation potential of the 30 reference chemicals based on performance standards using the iHCE-NY1 model correlated well with in vivo test results for eye irritation potential, with a sensitivity of 100%, a specificity of 60.0%, and an accuracy of 80.0%. Discussion and Conclusion: This development successfully established a simple and inexpensive method for in house fabrication of RhCE at laboratories, thereby providing a promising alternative to animal testing for assessing eye irritation potential using the iHCE-NY1 model.