Validation of porcine corneal opacity and permeability assay as an alternative to eye irritation tests

Abstract

The Draize eye irritation test has been changed to alternative methods based on 3 Rs (Replacement, Reduction, Refinement) of animal experiments. The bovine corneal opacity and permeability (BCOP) assay is well established as one of the alternative methods to the Draize test but the supply of bovine eyes from a slaughterhouse is not sufficient in actuality. The porcine corneal opacity and permeability(PCOP) assay have been proposed as a reliable alternative to the BCOP assay and the Draize test because porcine corneas have numerous advantages including structural similarities with human corneas and the stable capacity for a corneal supply. In this study, three cosmetics and seven chemicals that are already known as irritants at Draize score and the bovine corneal opacity(BCO) assay were tested by the PCOP assay for the first time in Korea. The porcine corneal opacity was measured by quantifying the ability of light to pass through a cornea using an opacitometer. The permeability was measured at 10 and 30 min time points after chemical exposure. The PCOP assay showed the high correlation with the Draize score and BCO assay. These results showed that the PCOP assay can be used as an alternative method for the BCO assay and the Draize test although it needs further studies about insoluble chemicals and others to increase reliability.