A new cell-based method for assessing the eye irritation potential of chemicals: an alternative to the Draize test

Using a human corneal cell line (HCE-T cells) and 2 evaluation criteria, we developed a new alternative method to assess the eye irritation potential of chemicals. We exposed HCE-T cells to different concentrations of 38 chemicals for 1h and measured relative cell viability (RCV) as an endpoint at each concentration. Using the RCV values, we calculated the RCV50. We also exposed HCE-T cells to 3 fixed concentrations of the 38 chemicals (5%, 0.5%, and 0.05%) for 1h and measured the RCV at each concentration. Using the RCV values at 5%, 0.5%, and 0.05%, we developed a new criterion for eye irritation potential (total eye irritation score, TEIS) and estimated the ocular irritancy. We then assessed the correlation of the results of RCV50 and TEIS with those of the Draize rabbit eye irritation. Both the RCV50 and TEIS results exhibited good positive correlations (sensitivity: 80.77%, specificity: 83.33%, and accuracy: 81.58% for TEIS; sensitivity: 73.08-76.92%, specificity: 75.00%, and accuracy: 73.68-76.32% for RCV50). We conclude that the new in vitro model using HCE-T cells is a good alternative evaluation model for the prediction of the eye irritation potential of chemicals.