[Allogenic heterotopic cartilage transplantation for primary corneal replacement in a rabbit model]

Aim of the present study was to investigate woundhealing after allogen heterotopic cartilage transplantation in a rabbit model.

Cartilage discs were transplanted by central lamellar keratoplasty (diameter 5.0 mm) in eleven New Zealand White Rabbits. Cartilage was harvested of the ears of rabbits at the day of transplantation. The cartilage discs 0.5-0.6 mm thick were prepared with 5.2 mm diameter and transplanted within 12 hours. Fixation was performed by eight 10-0 nylon sutures. Postoperatively, dexamethasone ointment containing gentamicin was applied three times a day for three weeks. Clinical course was documented by photographs. For histological examinations the transplanted eyes were enucleated after one day or three days, and after 3, 6 or 12 months.

Allogen cartilage healed firmly in the cornea within two months. During the course of observation the cartilage grafts thinned and were replaced by normal appearing collagen fibrills. In one case neovascularisation of the cornea occurred and reached the cartilage graft, but did not invate. Histologically, in all cases no leukocytes could be seen in the cartilage or its neighbourhood. The cartilage grafts did not proliferate and remained avascular. The intraocular structures showed no inflammatory reaction.

Allogen cartilage grafts to a clear corneal pounch do not induce an inflammatory reaction. Therefore, autologous cartilage prepared of ears seems to be useful biological material in ophthalmologic surgical procedures, for example to fill up corneal defects. To investigate if cartilage grafts will be helpful to stop neovascularisation in keratoplasty further studies with vascularisized corneas are necessary.