DETERMINATION OF THE INTRALABORATORY AND INTERLABORATORY REPRODUCIBILITY OF THE LOW-VOLUME EYE TEST AND ITS STATISTICAL RELATIONSHIP TO THEDRAIZE-EYE-TEST

The reproducibility of toxicologic test methods, including alternative tests, is a key scientific and regulatory concern. In the present wor k, historic rabbit eye irritation data were used to determine the intr a- and interlaboratory reproducibility of the low volume eye test (LVE T). The standard Draize eye irritation test was used as the basis for comparison. The LVET and Draize tests had similar degrees of intra- an d interlaboratory reproducibility as determined by examination of thei r coefficients of variation, although the variability in LVET results was directionally lower. Results from 70 parallel Draize and LVET test s indicated a strong positive association between results from the two tests, for corneal, iridial, conjunctival, and maximum average scores (MAS). Correlation coefficients were 0.60, 0.73, 0.69, and 0.73, resp ectively (P less than or equal to 0.0001). The linear relationship bet ween LVET and Draize MAS values was examined by regression analysis an d found to follow the relationship LVET MAS = 0.522 (Draize MAS). Thus , the LVET is at least as reproducible as the Draize test and gives re sponses that are (linearly) correlated to the Draize. The previous fin dings that the LVET is more predictive of human eye responses than the Draize test lends additional support for its use as a refined alterna tive to the Draize test. (C) 1996 Academic Press, Inc.