The in vitro assessment of eye irritancy using isolated eyes.

Rabbit eyes were removed and held in temperature-regulated chambers and irrigated with saline. A dose of 0.1 ml of test irritant was applied to each eye (six eyes per test material) and the induced change in corneal thickness measured over a 5-hour period, using a Zeiss photoslit-lamp microscope. A total of sixty materials were assessed and the results graded and compared with in vivo effects. The results show that this in vitro test can be relied upon to provide a rapid, accurate prediction of the irritancy potential in vivo, with a wide range of chemicals and, as such, offers a reliable alternative to the use of live animals.