THE USE OF IN-VITRO METHODS IN THE OCULAR IRRITATION ASSESSMENT OF COSMETIC PRODUCTS

The ocular tissue is a complex system consisting of corneal and conjun ctival epithelial cells, the underlying corneal stroma and associated endothelial cells. Exposure to chemicals may result in responses rangi ng from mild, slight redness and itching, to severe injury with loss o f corneal epithelium, damage to stroma, inflammatory infiltration and loss of vision. This complexity hinders the development of in vitro me thods able to replace animal testing. Various in vitro techniques have been proposed and subsequently developed as potential replacements fo r ocular toxicity screening on animals. Over the past 2 years, eight m ethods have been evaluated in these laboratories. The endpoint of thes e methods could be linked to one or to several clinical events occurri ng in the in vivo eye irritancy process described above. Using these s ystems, a battery of four complementary in vitro assays has been devel oped. For the categories of ingredients and cosmetic products investig ated, the promising results obtained suggest that in vitro methods of ocular risk assessment may be used increasingly in the future.