Applicability of a sheep model for training in plastic surgery of eyelids and orbit

Objective To test the applicability of a fresh tissue model for teaching facial plastic techniques and approaches to the eyelids and orbit. Design Observational animal experiments. Subjects Ten prepubescent sheep heads harvested following humane euthanasia at the completion of unrelated live animal research. Methods Young sheep were saline perfused at the end of an in vivo protocol. Head and neck tissues were harvested and refrigerated for 3-7 days. An experienced oculoplastic surgeon and an otolaryngologist explored the feasibility of common oculoplastic procedures in the ovine model. Results The model has potential for teaching basic principles in eyelid surgery including upper lid blepharoplasty, aponeurotic ptosis repair, upper lid gold weight lid loading for facial paralysis, lateral canthotomy and inferior limb cantholysis, lower lid tightening, and transconjunctival approach to the orbital floor. Eye muscle advancement, optic nerve sheath fenestration, and enucleation also accurately simulated human surgery. Anatomic variations limit the sheep model for orbital floor reconstruction and lacrimal drainage procedures. Conclusions The sheep head and neck provide an inexpensive, safe model for developing skills in several oculoplastic procedures. Formal simulation testing is needed to confirm these expert opinions.