The Isolated Chicken Eye test to replace the Draize test in rabbits : from development to implementation: “The long and winding road”

Dit proefschrift beschrijft de ontwikkeling, optimalisatie, validatie (binnen TNO) en toepassing van een alternatieve test met geïsoleerde ogen van kippen (de Isolated Chicken Eye, kortweg de ICE test) en in bredere zin de internationale validatie en acceptatie van de ICE test door overheidsinstanties

The chicken enucleated eye test (CEET) : a practical (pre)screen for the assessment of eye irritation/corrosion potential of test materials

The enucleated eye test with chicken eyes (CEET) obtained from an abattoir proved to be a valuable and practical alternative for the 'traditional' enucleated eye test with eyes of laboratory rabbits. Since 1992, the CEET has been incorporated in standard contract toxicity testing at the Toxicology Division of the TNO Nutrition and Food Research Institute as a (pre)screen for the Draize eye test with rabbits. The results of the first 44 compounds tested showed excellent correlation with the in vivo results. The CEET identified non-irritating or severely irritating compounds, and predicted (slightly to moderately) irritating compounds. Statistical analysis of the CEET and the rabbit in vivo scores showed high linear correlations between the critical values of both tests and confirmed the relevance of this assay with respect to ocular effects. In general, tiered in vitro/in vivo testing was considered a meaningful approach for further validation of alternative methods and for reducing the use of suffering of laboratory animals to a minimum. Tiered testing of compounds in cases of eye irritation hazard assessment should be incorporated in the legislation of the European Community. Chemicals/CAS: Irritant

Human volunteer study with PGME: Eye irritation during vapour exposure

The objective of this study was to establish the possible occurrence of eye irritation and subjective symptoms in human volunteers exposed to propylene glycol monomethyl ether (PGME) vapour at concentrations of 0, 100 and 150 ppm. Testing was conducted in 12 healthy male volunteers using a repeated measures design. Each subject was exposed for 2.5 h to each of the three exposure conditions that were spaced 7 days apart. The exposure sequences were counterbalanced and the exposure to the test substance and the effect measurements were conducted in a double-blind fashion. During all exposure sessions, 20 ppm diethyl ether was used as a 'masking agent' for vapour exposure. Measurements of pre- and post exposure eye redness, corneal thickness, tear film break-up time, conjunctival epithelial damage, blinking frequency, and subjective ratings on discomfort were used to evaluate the possible irritating effects of PGME. The results indicated no significant treatment effects for any of the objective parameters. Results of the subjective ratings indicated very slight effects on the eyes in the 150 ppm PGME condition only. No significant effects of treatment were found for the remaining questions concerning the perceived intensity of the smell in the room, the (un)pleasantness of the smell, the perceived effects on the skin, effects on the throat, shivering, muscle aching, and intestinal cramps. In conclusion, the results of the present study indicated minimal subjective eye effects at 150 ppm only, and no impact on the objective measures of eye irritation at either of the two exposure levels. It was concluded that the no adverse effect concentration for eye irritation due to PGME vapour was at least 150 ppm. © 2003 Elsevier Science Ireland Ltd. All rights reserved

The isolated chicken eye test as a suitable in vitro method for determining the eye irritation potential of household cleaning products

Eye irritation is an important endpoint in the safety evaluation of consumer products and their ingredients. Several in vitro methods have been developed and are used by different industry sectors to assess eye irritation. One such in vitro method in use for some time already is the isolated chicken eye test (ICE). This investigation focuses on assessing the ICE as a method to determine the eye irritation potential of household cleaning products, both for product safety assurance prior to marketing and for classification and labeling decisions. The ICE involves a single application of test substances onto the cornea of isolated chicken eyes. Endpoints are corneal swelling, corneal opacity and fluorescein retention. The ICE results were compared to historic LVET data in this study due to availability of such in vivo data and the ability to correlate LVET to human experience data on the outcome of accidental exposures to household cleaning products in general. The results of this study indicate that the ICE test is a useful in vitro method for evaluating the eye irritation/corrosion potential and establishing classification and labeling for household cleaning products. For new product formulations, it is best used as part of a weight-of-evidence approach and benchmarked against data from comparable formulations with known eye irritation/corrosion profiles and market experience. © 2009 Elsevier Inc. All rights reserved