EVALUATION OF THE EYTEX(R) SYSTEM AS A SCREENING METHOD FOR THE OCULAR IRRITANCY OF CHEMICAL-PRODUCTS

The EYTEX(R) method is an in vitro test used to predict ocular irritat ion, based on alterations in a protein matrix. We have evaluated this method with the aim of using it to screen chemicals. One hundred and f orty-two products (commodities and specialities), having a wide range of chemical properties and ocular irritation potential in the rabbit, were tested with either the standard, MPA, AMA, RMA or UMA protocols. The results were compared with in vivo data obtained previously for ea ch chemical and with the EEC labelling of eye irritation for dangerous substances. Intralaboratory repeatability and interlaboratory reprodu cibility were evaluated with seven other laboratories. Ninety-three pe r cent of the chemicals tested were qualified with the EYTEX method. T he coefficients of the linear correlation between the EYTEX score and the maximal Draize score an the one hand and the maximal corneal score on the other hand, were 0.69 and 0.65, respectively. Compared to the EEC classification, the labelling of dangerous substances and for the prediction of severe irritants, sensitivity, specificity and equivalen ce were 94%, 89% and 78%, respectively We observed nine false positive s (22%) and two false negatives (2%) for the identification of R41-, R 34- and R35-labelled, products. The predictive values, for identifying R41, R34 and R35 products and non-irritants or R36 products were 78% and 97%, respectively. Repeatability (6.3) and reproducibility (8.9) w ere quite satisfactory. The EYTEX system exhibits the characteristics of a goad screening method: compatibility with a large range of chemic als; a simple and rapid procedure; good intralaboratory and interlabor atory reproducibility; cost effectiveness; high sensitivity, specifici ty and predictive value; and a low incidence of false negative and fal se positive results. Based on these results, we consider the EYTEX met hod to be a valuable tool for the screening of eye irritancy.