A sheep whole-eye autotransplantation model

Abstract

Background: The aim of this study is to establish an in vivo large mammalian model that can form the basis for future immunosuppression research, nerve recovery research, surgical applicability, and training studies. Materials and Methods: An 18-month-old, 40 kg, curly breed sheep was used. A whole-eye autotransplantation was planned, including the upper and lower eyelids, lacrimal gland, and extraocular muscles. Intracranial intervention and inclusion of the bone segment were not considered. The frontozygomatic approach was used in the operation. Circulation was established by anastomoses of the internal ophthalmic vein and artery with elongated superficial temporal artery and vein with vein grafts. The optic nerve was repaired last. Blood circulation and the retina were checked by means of postoperative bleeding and indirect ophthalmoscope. Results: Using the internal carotid system, circulation of the entire eye and its appendages was achieved in the early period. The frontozygomatic approach facilitated nerve and vessel repairs and therefore shortened the ischemia time (16 min). Although circulation was established in the retina, local bleeding foci were detected. Pupillary, corneal, and palpebral reflexes could not be obtained from the animal. The animal died on the 10th day. Circulation of the autotransplanted tissue was present at this time, including the eyelids and appendages of the eye. Conclusion: The composite whole-eye autotransplantation model was successfully planned in vivo in a large mammal, the sheep, without the need for intracranial intervention, and by including all of the eye attachments based on the internal ophthalmic artery.