Retinal discoloration test.

There are considerable variations in the size and the origin of internal carotid arteries (ICAs) of New Zealand white rabbits. A simple test that could correctly identify the ICA could facilitate intracarotid delivery of drugs and embolic material for research in these animals. Five conventional methods for identifying the ICA proved inferior to a novel retinal discoloration test (RDT). A positive RDT implies a change in color of the retinal reflex after injection of 0.2 mL of indigo-carmine blue (ICB). We conclude that RDT is a useful test for correctly identifying and isolating the ICA in this animal species.