The Vitrigel-Eye Irritancy Test (EIT) method is an in vitro test method that allows the identification of test chemicals not requiring classification and labelling for eye irritation or serious eye damage. This test measures the eye irritation potential of a test chemical based on its ability to induce damage to the barrier function of the human corneal epithelium (hCE) models used in the Vitrigel-EIT method. It is known that chemicals that are irritating to the eye first destroy tear film and epithelial barrier function of the eye, subsequently induce epithelial cell death, and finally produce stromal degeneration and endothelial cell death, resulting in corneal opacity. Therefore, the change of the epithelial barrier function is a relevant endpoint for detecting eye irritation. In the Vitrigel Eye Irritancy test method , time-dependent changes in the Transepithelial Electrical Resistance (TEER) values are indicative of damage to the barrier function of the corneal epithelium following exposure to a test chemical; this situation is similar to the observed damage of the rabbit cornea following exposure to a test chemical, which is an important mode of action leading to damage of the corneal epithelium and eye irritation. The Vitrigel-Eye Irritancy Test (EIT) method can be used within the limited applicability domain of test chemicals having pH > 5.0 (based on 2.5% weight/volume (w/v) preparation).
