Impediments to eye transplantation: ocular viability following optic-nerve transection or enucleation

Abstract

Maintenance of ocular viability is one of the major impediments to successful whole-eye transplantation. This review provides a comprehensive understanding of the current literature to help guide future studies in order to overcome this hurdle. A systematic multistage review of published literature was performed. Three specific questions were addressed: (1) Is recovery of visual function following eye transplantation greater in cold-blooded vertebrates when compared with mammals? (2) Is outer retina function following enucleation and reperfusion improved compared with enucleation alone? (3) Following optic-nerve transection, is there a correlation between retinal ganglion cell (RGC) survival and either time after transection or proximity of the transection to the globe? In a majority of the studies performed in the literature, recovery of visual function can occur after whole-eye transplantation in cold-blooded vertebrates. Following enucleation (and reperfusion), outer retinal function is maintained from 4 to 9 h. RGC survival following optic-nerve transection is inversely related to both the time since transection and the proximity of transection to the globe. Lastly, neurotrophins can increase RGC survival following optic-nerve transection. This review of the literature suggests that the use of a donor eye is feasible for whole-eye transplantation.

Total Human Eye Allotransplantation: Developing Surgical Protocols for Donor and Recipient Procedures

“…12–16 Previously, the concept of eye transplantation had been thought of as unfeasible because of the inability of retinal ganglion cells to recover from injury, inadequate restoration of circulation, and immune rejection. 17 Now, with success in other modalities of vascularized composite allotransplantation, together with animal models of eye transplantation, 6,18 and emerging nerve regeneration strategies, 7–9 the need to elucidate the technical details of the surgical procedures for eye transplantation is also an important forerunner to a clinical eye transplant program.…”

Traumatic optic neuropathy: a review of the current literature

“…Ellenberg et al [23 ] and Koppanyi [24] have explored ways to perform successful whole-eye transplantation. This could provide additional treatment for direct TON.…”

“…This could provide additional treatment for direct TON. Potentially, whole-eye transplantation can provide a recipient with viable RGCs capable of regeneration, as well as the optical system necessary for forming a retinal image [23 ]. Currently, whole-eye transplantation is unsuccessful in mammals because of the ganglion cell axons inability to withstand transection, the inability to maintain circulation to the axons, and finally immune rejection of the transplant [23 ].…”

Ophthalmic transplantology: Anterior segment of the eye – Part I

“…At present, it is impossible to transplant the whole eyeball in humans for several reasons [4]. One is the viability of the donor’s eyeball, which is thought to sustain the functions of the photoreceptors shown in electroretinography.…”