The Bovine Corneal opacity and Permeability (BCOP) assay can be used for predicting mild, moderate, and severe ocular irritation through quantitative assessment of the changes in opacity and permeability of the bovine cornea. In addition, histological evaluation of the corneas can be performed to assess the depth of damage. The BCOP assay with histology was used to determine the ocular irritation potential of prototype cleaning products with antimicrobial claims according to the guidance provided by the EPA-Office of Pesticide Program (OPP). Several prototype cleaners with similar formulation were evaluated along with a reference material. The results of the BCOP assay showed noticeable differences among the products. The in vitro score, determined by changes in opacity and permeability, of the corneas treated with products ranged from ~15 to 80. These scores indicate mild, moderate, and severe irritation according to the guideline provided in the EPAOPP document. In addition, the histological evaluation of the corneas showed differences in the depth of damage between moderate and severe category products, confirming the in vitro score.
The assay distinguished ocular irritation potential among similar prototypes demonstrating its effectiveness during product development. Additionally, the results demonstrate the utility of the BCOP assay with histology as a stand-alone assay for eye irritancy evaluation in the EPAOPP program.