Rabbit eye irritation

Rabbit Eye Irritation. Instillation of the chlorodibenzodioxins into the conjunctival sac caused slight, transient pain and conjunctival inflammation, initially. Treatment with 2,3,7,8-TCDD was associated with delayed conjunctival chemosis 13-22 days later. By day 27, the chemosis had subsided, but the rim of the eyelid was thickened and encrusted. 

If the results of the rabbit eye irritation test can be extrapolated to man, accidental contact of these chlorodibenzodioxins with the eyes... 

Occupational toxicologists from several companies initiated a program to evaluate several experimental models as alternatives to the rabbit eye irritation test... 

HDI Toxicology Newsletter (1987). HDI develops rabbit eye irritation model. No. 6 (Enslein, K., Ed.) Health Designs, Inc., Rochester, New York. 

Jester, J.V, Ling, J., HarbeU, J. Measuring depth of injury (DOI) in an isolated rabbit eye irritation test (IRE) using biomarkers of cell death and viability. Toxicol In Vitro 24(2), 597-604 (2010). Epub 2009 Oct 24... 

For the rabbit eye irritation tests, the rabbits are placed in ventilated boxes with only the head free. Solutions of local anesthetics in 0.9 % saline are prepared and a volume of 0.2 ml is instilled into the conjunctival sac of one eye, leaving the other as control. The lower lid is retracted gently and held away from the cornea fro 1 min, thus insuring exposure to the solution. 

In the absence of any other relevant information, it is essential to obtain this via an internationally recognized corrosion/irritation test before proceeding to a rabbit eye irritation test. This must be conducted in a staged manner. If possible, this should be achieved using a validated, accepted in vitro skin corrosivity assay. If this is not available, then the assessment should be completed using animal tests (see the skin irritation/ corrosion strategy, section 3.2.2). 

Rabbit Eye Irritancy Testing Widely Used Study Design... 

To assess the adequacy of the currently employed eye irritation tests in fulfilling the objectives behind their use, we must evaluate them in terms of (1) their accuracy (how well they predict the hazard to humans) (2) whether comparable results can be obtained by different technicians and laboratories and (3) what methods and designs have been developed and are being employed as alternatives to rabbit eye irritation tests. Assessing the accuracy of rabbit eye irritation tests - or indeed, of any predictive test of eye irritation - requires that the results of such tests be compared to what happens in humans. Unfortunately, the human database for making comparisons is not large. The concerns, however, have been present almost as long as the tests have been performed. 

A number of alternatives have been proposed and adapted for the performance of rabbit eye irritation tests. These alternatives have been directed at the twin objectives of making the tests more accurate in predicting human responses and reducing both the use of animals and the degree of discomfort or suffering experienced by those that are used. 

Marzulli FN, Ruggles DI (1973) Rabbit eye irritation test collaborative study. J Assoc Off Anal Chem 56 905-914... 

Over the years a numbo of alternative test systems have been described in the literature. These include the use of tissue culture, excised animal organs, bactoial systems, computer modeling, protozoan mortality inhibition, chorioallantoic membrane inflammation, and specific biochemical reactions [23]. Most of these alternative test procedures have been proposed or developed with the objective of reducing or replacing animal LDjg toxicity tests and the controversial Draize rabbit eye irritancy test [24]. 

The Draize rabbit eye irritation test [175] has been used for decades as an animal model to predict eye irritation in humans. However, because the rabbit eye does not tear, and of course the human eye does, this model is imperfect for predicting irritation to human eyes. Obviously, the rabbit eye test cannot be used to evaluate no more tears shampoo claims. A large number of laboratory models have been examined over the past decade to provide a predictive tool to be used either in place of or to minimize the use of animals for eye testing. Among these models, the HET-CAM test and the CAM-VA assay show the most promise [176]. 

Bruner, L.H., Kain, D.J., Roberts, D.A., Parker, R.D., Cbrien, K.A.F., Uttley, M. and Walker A.P., 1991, An evaluation of five potential alternatives in vitro to the rabbit eye irritation test in vivo, Fundam. Appl Toxicol 17 136. 

No significant adverse health effects have been reported for Butvar or Formvar. In acute toxicity studies with rats and rabbits, polyvinyl butyral resin is practically nontoxic by oral ingestion (LD50 > 10,000 mg/kg) or dermal application (LD50 > 7,940 mg/kg). Butvar had only slight rabbit eye irritation (2.80n a scale of 0-110) and did not irritate the skin. These resins are not considered carcinogenic. 

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