SEVERAL investigators* have observed regressive nerve changes of the Wallerian type, followed by progressive changes, after experimental keratotomies and keratoplasties. It is true that one has more material for the histologic demonstration of what happens with the corneal nerves in experimental keratoplasty, but when one tests the rabbit for return of sensitivity, one can obtain little information of value. The experimental grafting can be suitably timed to study the condition of the nerves of the graft at different periods after the operation, an investigation which is of value.
With human keratoplasty, on the other hand, morphologic studies are limited to those cases in which there is eventual need of repeating the operation, and this is done at a time, not when it is desirable for the study of the nerves, but when it is convenient and necessary for the patient. Most retransplants are made several months after the first operation,
ESCAPINI H. NERVE CHANGES IN THE HUMAN CORNEAL GRAFT. AMA Arch Ophthalmol. 1955;53(2):229-235. doi:10.1001/archopht.1955.00930010231010