Grafted Eyes of Adult Triturus Viridescens with Special Reference to Repeated Return of Vision

Abstract

The present experiments are part of a series of investigations which have already been reported 1 ,²,³,⁴ on grafted larval and adult amphibian eyes. Over 600 grafts of functional eyes have been studied in various types of operations. All eyes while living have been observed daily and the findings have been correlated with closely staged histological preparations.

This report is based on the observations of 140 reimplanted and transplanted eyes in the adult Triturus viridescens. In all cases the eye has been placed in the orbit, i. e., in its normal environment. In some cases the eyes have been regrafted as many as 2 and 3 times involving reimplantation and transplantation in different orders of sequence.

Following operation some reduction in the size of the eye takes place as in the case of larval eyes. The latter recover their original size after the return of circulation and soon become equal to that of the normal control. In adult eyes the reduction in size is maximally attained at a time (20–25 days) when the degeneration of the retina has reached its height. In most cases there is no complete recovery in the size of the eye although in other respects it may appear normal except for slight histological changes.

Observed return of circulation in the superficial vessels of the iris usually occurred within the first week after operation, the earliest being on the fifth day. However, temporary opacities of the cornea in some cases prevents the observation of the earliest movement of blood cells within the vessels.