AN IN-VITRO HEMOLYSIS TEST AS AN ALTERNATIVE TO THE DRAIZE TEST FOR OCULAR IRRITATION

A haemolysis test has been evaluated as an alternative to the Draize eye test (Draize et al. 1944) for ocular irritancy. Haemolysis was seen with corrosive/severe and severe/moderate eye irritants but was negligible with non-irritant substances. Although not quite as sensitive as dog blood to irritants, human blood gave comparable results and was also more easily available in quantity. As with other in vitro tests, some false-positive results were given by the haemolysis test and also a few false-negative results. However, in all cases these were explicable given the physical and chemical properties of the materials. pH of test solutions did not seem to be a complicating factor. There was good correlation between the results of this test and published in vivo data. Although it may not yet entirely replace the in vivo model, the haemolysis test is a valuable preliminary stage in a tiered approach to eye irritancy screening.