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

ed from identified articles to determine ocular viability in each of the above three categories and for factors that improve ocular viability. For evidence of visual function, only articles in which the eye was completely enucleated and reimplanted were included. Articles in which the optic nerve was transected but the eye was not enucleated were excluded. We relied on each identified article’s conclusion to assess evidence of visual function. Outcome of whole-eye transplantation in cold-blooded vertebrate was compared with outcome in mammals. In total, 17 articles regarding whole-eye transplantation in both coldblooded vertebrate and mammals satisfied our inclusion criteria. For evidence of preserved outer retina function, only articles that evaluated outer retina function (with ERG) at greater than one time point were included. Articles, in which an enucleated eye was perfused, but maintenance of ocular viability at greater than one time point was not evaluated, were excluded. Articles in which there was no attempt to evaluate retina function were also excluded. In total, eight articles regarding ex vivo perfused eyes satisfied our inclusion criteria. For RGC survival, articles were divided into two categories based upon the location of optic-nerve transection—intraorbital or intracranial. Articles that evaluated RGC survival at (at least) two of the following three time points were included: 1–3 days post-transection, 10–15 days post-transection and 26–30 days post-transection. Only articles in which complete optic-nerve transection (one optic-nerve crush article was included) was performed and in which quantification of RGC survival at more than one time point was assessed were included. In total, 12 articles regarding survival of RGC after optic-nerve transection satisfied our inclusion criteria. Finally, articles that demonstrated factors that improved RGC survival were included. The effect of the positive factors is reported as the percentage difference of RGC survival between the eye that was treated with the factor, and the eye that was not treated. This percentage difference was calculated by subtracting the percentage (of healthy control) of RGC survival in the untreated eye from the percent (of healthy control) of RGC survival in the treated eye. The result of this calculation yielded the ‘‘percentage survival difference.’’ In total, 45 articles regarding factors that increase RGC survival satisfied our inclusion criteria. A total of 82 articles were included in the study, and a total of 93 articles are referenced. A total of 60 articles were excluded based on our exclusion criteria.