The fate of scleral grafts in the cornea.

There have been reports of the clearing of sclera that has been grafted into the cornea. This clearing was studied in the rabbit by transplanting full-thickness scleral buttons or by implanting slivers of sclera, both autografts and allografts, into the cornea. Some clearing around the edges of the implanted scleral tissues was observed to take place slowly over the following months. Electron microscopic observation of the borders of either type of graft showed that the collagen fibrils of the sclera were breaking down either by unraveling into smaller fibrils similar in diameter to those of the cornea by fraying into microfibrils. Attracting blood vessels over the scleral slivers did not appear to accelerate the changes. Both active macrophages and fibroblasts could be found in the transitional area.