Rabbit retinal ganglion cells survive optic nerve transection and entubulation repair with type I collagen nerve guide tubes.

The major objective of the experiments reported in this paper was to qualitatively test the hypothesis that rabbit retinal ganglion cells survive optic nerve transection and entubulation repair of the proximal optic nerve stump. The optic nerve of rabbits was transected immediately behind the globe, and a 1-cm length of a Type I collagen nerve guide tube was sutured onto the short proximal stump. The nerve guide was either left empty or was filled with a Type I collagen gel (Vitrogen, Collagen Corp.). Following 8-12 weeks survival time, the animals were sacrificed and the retinae were prepared as whole mounts and processed for immunocytochemistry using an antibody which selectively labels the retinal ganglion cells. Although no formal cell counts were carried out, the animals which received Vitrogen within the nerve guide showed a qualitative enhancement of retinal ganglion cell survival compared to the group with the nerve guide alone. The results suggest that specific manipulations of the central nervous system microenvironment may enhance neuronal survival following axonal transection.