Structural and Viability Assessment of Bovine Corneas Preserved at an Accessible Low-Temperature (−20 °C) for Eye Irritation Models

In vitro ocular irritation testing requires the use of freshly excised bovine corneas, which limits broader adoption in laboratories with restricted access to slaughterhouse material. This study investigated a practical and accessible low-temperature preservation strategy focused on maintaining structural and cellular integrity. Bovine corneas were stored at −20 or −80 °C using two commonly available cryoprotective agents: dimethyl sulfoxide (DMSO) and ethylene glycol (EG). Preservation outcomes were assessed through corneal transparency, histological architecture, and endothelial viability. Among the tested conditions, storage at −20 °C with 10% DMSO provided the most consistent preservation of structural morphology and transparency. This protocol provides a cost-effective foundation for extending the usability of excised corneas and supports future efforts to expand the accessibility of in vitro eye irritation models in laboratories with limited infrastructure.