Although this test method is still in development, we welcome collaborations with interested parties. In addition, we provide customized “research-level” depth of injury testing services.
New laws are currently in the process of being implemented in the United States and the European Union to ban the use of animals in product testing and labeling for potential ocular irritation. Despite this fact, there is currently no single nonanimal test or combination of nonanimal tests that can accurately identify reversible ocular irritants. This deficiency has the potential to severely impact our ability to adequately advise and protect consumers and inform manufactures of potentially harmful and/or dangerous products.
Past studies by various groups (see references below) have focused on assessing and correlating the irritation potential of chemicals with the initial extent of injury in live rabbit eyes. The results of these studies identified that the irritation potential of a material is dependent on the acute depth of injury (DoI), such that nonirritants damage only the superficial corneal epithelium, reversible irritants damage the epithelium and anterior stroma, and irreversible irritants damage the epithelium and deep stroma. Overall, these findings suggest that there is a fundamental mechanistic relationship between the initial injury, regardless of the chemical process, and the final outcome that involves both the corneal epithelium and underlying corneal stroma (see references 1-6 below). If this hypothesis is correct, a major limitation of alternative tests is the lack of the assessment of stromal damage needed to detect reversible irritants. To address this limitation, we have developed prediction models that can be applied to an in vitro food source tissue test used measure depth of injury.
As recently reported in our publication An in vitro depth of injury prediction model for a histopathologic classification of EPA and GHS eye irritants we developed an IVD prediction model to measure and classify the toxic effects of ocular irritants. This approach uses food-source, otherwise discarded eyes ("ex vivo"), that are exposed to potential ocular irritants for 1 minute using a dosing ring. Following the subsequent rinsing of the eyes and 24 hours of organ culture, the DoI to the cornea is measured histopathologically using proprietary methods. The data are then quantified and related to a prediction model that results in an ocular irritancy classification, including the GHS 2A/2B reversible irritant classification.
1. Jester JV, Maurer JK, Petroll WM, Wilkie DA, Parker RD, Cavanagh HD: Application of in vivo confocal microscopy to the understanding of surfactant-induced ocular irritation. Toxicol Pathol 1996, 24:412-428.
2. Jester JV, Li HF, Petroll WM, Parker RD, Cavanagh HD, Carr GJ, Smith B, Maurer JK: Area and depth of surfactant-induced corneal injury correlates with cell death. Invest Ophthalmol Vis Sci 1998, 39:922-936.
3. Jester JV, Petroll WM, Bean J, Parker RD, Carr GJ, Cavanagh HD, Maurer JK: Area and depth of surfactant-induced corneal injury predicts extent of subsequent ocular responses. Invest Ophthalmol Vis Sci 1998, 39:2610-2625.
4. Jester JV: Extent of corneal injury as a biomarker for hazard assessment and the development of alternative models to the Draize rabbit eye test. Cutan Ocul Toxicol 2006, 25:41-54.
5. Maurer JK, Li HF, Petroll WM, Parker RD, Cavanagh HD, Jester JV: Confocal microscopic characterization of initial corneal changes of surfactant-induced eye irritation in the rabbit. Toxicol Appl Pharmacol 1997, 143:291-300.
6. Maurer JK, Molai A, Parker RD, Li L, Carr GJ, Petroll WM, Cavanagh HD, Jester JV: Pathology of ocular irritation with bleaching agents in the rabbit low-volume eye test. Toxicol Pathol 2001, 29:308-319.
We welcome interested parties and stakeholders to partner and collaborate with us as well as use our IVD research-level testing services.
Collaboration requests should be directed to:
Lebrun Labs LLC
Phone (714) 345-4689