Evaluation of the HET-CAM-TSA method as an alternative to the draize eye irritation test.

The Hen's Egg Test-Chorioallantoic Membrane (HET-CAM) method was modified in our laboratory by means of microscopic evaluation, a clear description of the three in vitro endpoints (haemorrhage, lysis and coagulation) and the use of a test substance applicator (TSA). A previous study on 46 chemicals demonstrated the usage of the HET-CAM-TSA assay as a screening test for eye irritancy. In order to extend our database and to come to a more reliable conclusion concerning the use of the HET-CAM-TSA method, a second set of 60 test substances was tested.

Evaluation of a modified HET-CAM assay as a screening test for eye irritancy.

The hen's egg test-chorioallantoic membrane (HET-CAM) assay, an alternative to the Draize eye irritation test, was developed by Luepke and has been improved on by means of a microscopic examination and the use of a test substance applicator (TSA). The TSA is a double teflon ring in which a perlon mesh is locked, and has several advantages over conventional protocols, reducing subjectivity of the method and avoiding the need for rinsing after treatment. It was confirmed by statistical analysis that the HET-CAM-TSA method can reproduce potentialin vivo irritant effects on the conjunctiva.