PRS AAPS Oral Proofs 2016
Kia M. Washington, MD,* Yang Li, MD, PhD,* Chiaki Komatsu, MD,* Edward H. Davidson, MA, MBBS,* Maxine R. Miller, MD,* Bo Wang, BS,† LiWei Dong, MD,* Lin He, MD,* Yolandi van de Merwe, BA,* Leon Ho, BA,* Mario G. Solari, MD,* Eric W. Wang, MD,* Vijay S. Gorantla, MD, PhD,* Dawn J. Wang, MD,* Jenny Y. Yu, MD,* Juan C. Fernandez-Miranda, MD,* Joel S. Schuman, MD,* Kevin C. Chan, PhD*
From the *University of Pittsburgh, Pittsburgh, Pa.; and †University of Pittsburgh School of Medicine, Pittsburgh, Pa.
PURPOSE: Development of a reliable animal model for testing immunomodulation and neuroregeneration strategies and development of human surgical protocols are vital in realizing eye transplantation.
METHODS: Syngeneic orthotopic transplants were performed in Lewis rats (n = 20). Anastomoses between common carotid arteries and external jugular veins and optic nerve coaptation were performed. Slit lamp examination, optical coherence tomography, histology, and magnetic resonance imaging confirmed structural integrity, viability, and aqueous humor dynamics. Human cadaveric heads (n = 8) donor procurement involved an orbital, endonasal, and transcranial approach. Sequential arterial and venous anastomoses and cranial nerve II to VI coaptations to recipients were performed.
RESULTS: Rat survival was 75% (15/20), graft survival 87% (13/15), mean ischemia time 1.98 hours, mean donor 1.15 hours, and mean recipient 2.28 hours. Slit lamp examination, histology, and OCT revealed structural integrity. There was retinal blood flow, normal blood-aqueous barrier, and blood-retinal barrier. Transplants had normal intraocular pressures. Feasibility of cadaveric transplantation was established. Mean donor ophthalmic artery length and caliber were 13.5 and 1 mm, respectively, but with a stem of paraclival internal carotid artery were 33 and 2 mm. Mean optic nerve length was 25 mm from apex to annulus of Zinn and 14 mm from annulus of Zinn to chiasm. Cranial nerves III to VI lengths were 10 to 14 mm. Candidate recipient vessels required vein grafting.
CONCLUSIONS: This animal model and surgical protocol serve as a benchmark for ongoing investigation, ultimately potentiating the possibility of vision restoration transplantation surgery.