Chorioallantoic membrane vascular assay

The CAMVA assay assesses the possible detrimental effects which potential eye irritants have on the blood vessels of the embryo's CAM (chorioallantoic membrane).

In preparation of the test a small opening is cut into the shell of the egg four days after fertilization and a small amount of albumen is removed to allow optimal growth of the CAM. The opening is resealed and the eggs are incubated for a further 6 days. The age of the CAM used in the test has been limited to 10 days in order to comply with the legislation in the EU countries which prohibits experiments on chick embryos that are older than 10 days (Bagley et al., 1992, 1994).

On day 10 the test substance is applied directly onto a small area of the CAM. After exposure for 30 minutes the eggs are examined for any vascular change in the CAM, e.g. haemorrhaging, hyperaemia (capillary injection) or the occurrence of vessels devoid of blood flow (ghost vessels). The concentration of test materials eliciting such damaging effects in 50 % of the eggs is calculated as toxicological endpoint.