Cytotoxicity assay to assess eye irritation - A comparison with other methods and possible strategies for use

Many in vitro methods can be used to classify eye irritation or damage caused by exposure to a substance. In this study, a recently described method called the Cytotoxicity Assay to Assess Eye Irritation (CEI) was compared with other selected in vitro methods adopted in the OECD guidelines. Furthermore, the influence of combining more than one in vitro method was investigated. Basic performance indices were considered and a risk assessment based on the number of correct and incorrect results (overestimated or underestimated) was performed. The CEI results were similar to those of other in vitro tests, however, the CEI can also directly classify substances irritating to the eyes. When the CEI preceded an eye irritation test based reconstructed human corneal-like epithelium, there were fewer underestimates compared with other method combinations. This combination can better protect human health and provides results comparable to those obtained in animal tests.