[Morphological and functional studies on nerve regeneration after corneal nerve injuries]

Using gold chloride impregnation of nerves and horse-radish peroxidase (HRP) axoplasma retrograde tracing technique, we monitored nerve regeneration over a period of 6 months following penetrating perilimbal incisions and penetrating keratoplasties (PKP) in rabbits. Post-operatively, at 1 month after a 180 degrees perilimbal incision, loose unconnected subepithelial plexus were present in the limbus, at 2 months 1-2 bundles of deep stromal nerve were seen in the stroma and by 6 months only a few stromal nerves regenerated. There was no difference in nerve regeneration between post-operative autograft and allograft PKP. By 6 months, the quantity of HRP-labelled cells in the trigeminal ganglia was less than the normal level. The results indicated that nerve regeneration by 6 months after corneal nerve injuries was inadequate to restore a normal corneal nerve extent and function.