The regeneration of corneal nerve in the graft after penetrating partial homo-keratoplasty had been observed histologically in the experimental rabbits and also the influence of thiamine hydrochloride on nerve regeneration had been studied.
Cornea-grafts obtained from the central portion of the cornea by 6mm trephine were transplanted each other among the rabbits and given 8 sutures in situ under deep sodium pentobarbital anesthesia.
Thiamine hydrochloride were given daily does of 5mg/kg body weight to the grouped rabbits intramuscularly.
Enuculeations were done in 5 days, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,14,18, 20,22, 24,.26, and 27 weeks after transplantation.
Preparations were made with 10-15m paraffine serial sections, both of cross and flat, and modified Romanes´ silver stain was applied.
The results were as follows:
1) Control group: In 5 days after operation, fine nerve fiber were regenerated from the cutted nerve stumps of the host-cornea. After 1 week, nerve plexus were formed in the host-cornea around scar tissue and few fibers penetrated into the scar tissue. After 2 weeks, fine regenerating nerve fibers were found in the transplanted cornea-grafts. Thereafter, numbers and size of the regenerated nerve fibers increased gradually. In 9 weeks after transplantation, nerve innovation in the transplanted cornea-graft was similar to normal cornea.
2) Thiamine hydrochloride treated group: In 5 days after operation, fine regenerating nerve sprouts from the cutted nerves tumps in the host-cornea formed loose nerve plex us and few fibers penetrated into the scar tissue. After 1. Week, regenerating nerve fibers were already found in the periphery of the transplanted cornea-grafts. In process of experimental time, nerve fibers in the cornea-grafts more actively regenerated compared with control group. In 7 weeks after homo-corneal transplantation, nerve innervation in the grafts was the same as normal cornea.
3) Thiamine hydrochloride remarkably accelerated nerve regeneration in the transplanted cornea-grafts after penetrating partial homo-keratoplasty.
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