Workshop on eye irritation testing: practical applications of non-whole animal alternatives

In November 1993, over 200 people from 14 nations participated in an IRAG workshop on eye irritation testing. The goal of the workshop was to set a course for the scientific approval and acceptance of non-whole animal alternatives to the Draize eye test. Through a retrospective review of existing in vitro and in vivo data by expert working groups, the endeavour examined the current status of practical application of in vitro alternatives used to predict eye irritation. Over 74 data sets from 59 laboratories were reviewed for approximately 26 different test methods. The submissions were illustrative of varied approaches and broad applications of in vitro assays. It was concluded that: (1) data are insufficient to support the total replacement of in vivo ocular irritancy testing with in vitro methods; (2) alternative methods to the in vivo standard (Draize) are currently being used extensively by industry as screens in the risk assessment process for product development, and (3) based on current practices for ocular irritancy testing, it appears that some models exist that may have the potential to reduce the need for new animal testing, provided they are validated and conducted under well defined conditions. Several recommendations are proffered to facilitate scientific review of in vitro and in vivo data sets in parallel: for example, basic research is encouraged to further identify mechanistic endpoints targeting human ocular injury; a chemical test bank is necessary for testing standards; an international data bank should be established; test batteries need to be identified that adequately test novel substances for safety; a third party needs to take the lead to identify promising tests and to facilitate validation studies; and international harmonization of method development, validation and acceptance should be given high priority. Grateful appreciation is conveyed to the many contributors to this complex endeavour.