The Ex Vivo Eye Irritation Test as an Alternative Test Method for Serious Eye Damage/Eye Irritation

Abstract

Ocular irritation testing is a common requirement for the classification, labelling and packaging of chemicals (substances and mixtures). The in vivo Draize rabbit eye test (OECD Test Guideline 405) is considered to be the regulatory reference method for the classification of chemicals according to their potential to induce eye injury. In the Draize test, chemicals are applied to rabbit eyes in vivo, and changes are monitored over time. If no damage is observed, the chemical is not categorised. Otherwise, the classification depends on the severity and reversibility of the damage. Alternative test methods have to be designed to match the classifications from the in vivo reference method. However, observation of damage reversibility is usually not possible in vitro. Within the present study, a new organotypic method based on rabbit corneas obtained from food production is demonstrated to close this gap. The Ex Vivo Eye Irritation Test (EVEIT) retains the full biochemical activity of the corneal epithelium, epithelial stem cells and endothelium. This permits the in-depth analysis of ocular chemical trauma beyond that achievable by using established in vitro methods. In particular, the EVEIT is the first test to permit the direct monitoring of recovery of all corneal layers after damage. To develop a prediction model for the EVEIT that is comparable to the GHS system, 37 reference chemicals were analysed. The experimental data were used to derive a three-level potency ranking of eye irritation and corrosion that best fits the GHS categorisation. In vivo data available in the literature were used for comparison. When compared with GHS classification predictions, the overall accuracy of the three-level potency ranking was 78%. The classification of chemicals as irritating versus non-irritating resulted in 96% sensitivity, 91% specificity and 95% accuracy.

Retinal Organ Cultures as Alternative Research Models

“…The Ex Vivo Eye Irritation Test (EVEIT), which is used to determine the potential of substances to cause irritation to the cornea, is a great example of a replacement method that uses rabbit eyes as a source of tissue. [7][8][9] A combination of tests, such as the EVEIT and the bovine corneal opacity and permeability assay, offers the advantage of creating even more realistic conditions for preclinical drug testing, and for toxicity testing, which could accelerate the approval and registration of chemicals . 10,11 A comparison between the Draize rabbit eye irritation test, which used to be the standard in vivo acute toxicity test (and was initially used for cosmetics testing), and the Isolated Rabbit Eye (IRE) test showed that the IRE test could successfully be used for the in vitro testing of eye irritation potential, thus representing a good alternative to the Draize test.…”

“…The Ex Vivo Eye Irritation Test (EVEIT), which is used to determine the potential of substances to cause irritation to the cornea, is a great example of a replacement method that uses rabbit eyes as a source of tissue. 7 –9 A combination of tests, such as the EVEIT and the bovine corneal opacity and permeability assay, offers the advantage of creating even more realistic conditions for preclinical drug testing, and for toxicity testing, which could accelerate the approval and registration of chemicals . 10,11…”

An in vitro depth of injury prediction model for a histopathologic classification of EPA and GHS eye irritants

“…In this regard, it is noted that a recent alternative model, the Ex Vivo Eye Irritation Test (EVEIT), which uses O.C.T. imaging, has proven valuable for the categorization of ocular irritation based on both early and later responses (64–72 h) (Frentz et al, 2008; Spoler et al, 2010; Spoler et al, 2015). While the EVEIT cannot be used to detect a difference in stromal DoI using O.C.T., this is most likely due to the limitation in O.C.T.…”

Development of a novel ex vivo equine corneal model

“…In physician ophthalmology, there is a move to eliminate the Draize test due to animal welfare concerns . As a result, there is a rise in the use of ex vivo corneal models used to study the effects of different compounds on the eye . Our goal is to utilize the best possible equine corneal ex vivo model to study equine corneal disease.…”

“…Ex vivo models have been used to study a variety of different ocular diseases in different species . One important benefit of an ex vivo model is that it allows for a more adequate representation of in vivo conditions.…”