Return of Vision and Other Observations in Transplanted Amphibian Eyes.

Abstract

Return of vision and various other observations were reported by Stone and Ussher 1 on replanted eyes in Amblystoma punctatum larvae. The present paper gives a report of similar observations based on 126 transplanted larval eyes in the same species. The methods of technique in operation were similar to those employed by the above mentioned authors. In nearly all cases right eyes were exchanged between pairs of larvae 22 mm. in length. Animals were killed at intervals of a few days from the time of operation until long after metamorphosis. Observations obtained of eyes in the animals while living have been correlated with those obtained from a microscopic examination in 62 cases.

Very little hemorrhage was encountered. Resorption of the eye, when it took place, could usually be correlated with known injuries to the bulb at the time of operation, or to prolonged use of anesthesia, or to too strong anesthesia. Slight reduction in the size of the transplanted eye was noted in most cases after operation, but usually the normal size appeared to be regained within 5 weeks. In fact the general macroscopic appearance of the transplanted eyes was so similar to that of the normal eyes in most cases that it was often difficult to differentiate between them. Shortly after operation the pupil of the transplanted eye showed some dilatation, but later approached normal size.

Return of circulation was first noted within the superficial vessels of the iris as early as 24 hours after operation in one case. The average time, however, was about the 4th day. Return of some ocular movement was observed as early as 7 days after operation, but in most cases this occurred much later. Pupillary and corneal reactions did not occur in any transplanted eyes until the animals had begun metamorphosis. This is always true of normal Amblystoma punctatum eyes.