Performance of the Hen's Egg Test - Chorioallantoic Membrane (HET-CAM) test method in detecting ocular corrosives and severe irritants NY Choksi1, DG Allen1, BC Blackard1, CJ Inhof1, RR Tice1,
JF Truax1, WS Stokes2
1. Integrated Laboratory Systems, Inc./NICEATM, RTP, NC, USA
Ethical (animal welfare), economic (development of
higher throughput testing), and scientific (development of mechanistic
studies) concerns have led researchers to develop in vitro alternatives
for the current in vivo rabbit eye test. NICEATM evaluated four in vitro
f test methods for their ability to identify substances that cause
ocular corrosion or severe irritation. One of these test methods,
HET-CAM, was developed to mimic the mucosal eye tissues. The ability of
HET-CAM to correctly identify ocular corrosives and severe irritants
using available HET-CAM and corresponding in vivo rabbit eye test data
was evaluated according to current hazard classification schemes for the
U.S. Environmental Protection Agency, the European Union, and the UN
Globally Harmonized System. Results from an interim analysis suggest
that HET-CAM has a high false positive rate. However, the assay may
still be useful in a weight-of-evidence tiered testing strategy, where a
positive substance could be either retested with a modified method to
confirm the result or used to classify and label a substance.
Substances with negative results would undergo additional testing. This
approach would reduce the number of animals used for eye irritation
testing and the number of animals experiencing pain and distress. A
proposed standardized test method protocol and a proposed list of
reference substances have been developed for use in future validation
and/or testing studies to further characterize the accuracy, the
reliability, and the applicability domain of HET-CAM for the detection
of ocular corrosives and severe irritants. ILS staff supported by NIEHS
contract N01-ES 35504. P160 Date: Tuesday, August 23, 2005, 13.00-14.00 h 5.5 Session: Advancements and Needs for Developing and Validating Alternatives for Ocular Irritancy and Corrosivity Testing. This page was last updated May 9, 2007 Contact the webmaster Return to the NICEATM/ICCVAM Home Page |