Purchase this article with an account.
Norma Allemann, Daoud Fahd, Wallace Chamon, Jin-Hong Chang, Sandeep Jain, Dimitri T. Azar; Impediment to Whole Eye Transplantation: An Animal Model and Surgical Techniques. Invest. Ophthalmol. Vis. Sci. 2012;53(14):293.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We have previously described the ocular viability impediment to whole eye transplantation. In this report, we describe and attempt to overcome the impediment relating to an animal model. Specifically, we describe the post mortem surgical exposure and feasibility of retro-orbital optic nerve and vascular anastomosis in a porcine model.
Fifty (50) pigheads from the slaughter house were dissected to elucidate the porcine orbital anatomy and enumerate the steps for total eye transplantation. Mercox dye was injected into main arteries and veins to trace the vascular anatomy of the orbit. The external ophthalmic artery (EOA) was identified and cannulated. Fluorescein sodium or Mercox dye was injected into the cannulated EOA which was then anastomosed to the external carotid artery. Fundus photos and fluorescein angiograms were taken. Retinas were mounted and imaged.
The EOA was successfully cannulated and anastomosed to the external carotid artery using a specially-designed cannula for a long extraorbital course. EOA anatomy was elucidated and its course around the ON head before entering the globe was noticed. Dye was recovered in the retina: the vascular tree is similar to that of humans with both superior and inferior vascular arcades and a temporal area devoid of blood vessels. The retina lacks a tapetum and a central retinal artery was not seen. The ON is covered with meninges up to the lamina cribrosa with the extraocular muscles enveloping it. It was accessed without cutting any muscles, the meningeal sheath was opened, the ON totally transected, and the meninges resutured. Both sections of the transected ON were correctly apposed without suturing the ON.
Adequate surgical exposure for visualization and retro-orbital optic nerve and vascular anastomosis is feasible in the porcine model. Main anatomic landmarks in the pig have been elucidated to properly address vascular and neural anastomosis. Future work is needed to prove its feasibility in living animals.
This PDF is available to Subscribers Only