Long-Term Cryoprotectant-Augmented Deep Freezing of the Animal Whole Globe for the Maintenance of Corneal Clarity

Purpose: Round-the-clock on-demand availability and corneal cloudiness are the two major problems with animal eyes for surgical practice. The purpose of this investigation is to assess the usability of long-term deep freezing for the preservation of enucleated sheep eyes and the adjunctive role of intracameral cryoprotective agent on corneal clarity. Methods: Thirty-two enucleated fresh sheep eyes were obtained from the slaughterhouse. With an insulin syringe, 0.5 mL of aqueous was tapped from the 16 right globes; it was replaced by an equivalent intracameral cryoprotection solution. Treated eyes were kept in receptacles filled with 1 cc of the same cryoprotectant and stored in a deep freezer (-80˚C). Left eyes were served as controls (untreated globes) and stored in the same condition. Six months later, globes were defrosted and corneal clarity was compared in a paired and masked fashion. Results: All treated globes had clearer corneas as compared with untreated globes and they were all successfully applied for anterior segment surgical practice. Conclusion: Long-term deep freezing with adjuvant intracameral cryoprotectant is effective for the preservation of corneal clarity of animal whole globe. This allows round-the-clock on-demand availability of animal eyes with clear corneas for surgical practice in ophthalmology skill labs.