The world’s first partial face and whole eye transplant has yielded important insights towards the development of functional eye transplants.
Over one year ago, a surgical team at NYU Langone Health transplanted part of a donor face onto a 46-year old power line worker who had suffered extensive facial injuries and the loss of his left eye. They also transplanted a complete eye into the patient, connecting it up to blood vessels and nerves, to see whether it was possible for an eye to survive. Now, findings on the health of the transplanted eye published in JAMA reveal that the eye is healthy but no light has been seen from it.
For the roughly 40 million people around the world without sight in either eye, stem cell research has been the most recent hope for regaining vision in many cases of trauma and disease.
In the eye transplant, the optic nerve was attached and immunosuppression used. Fluorescein angiography showed that perfusion of the globe and retinal were maintained throughout the immediate postoperative period. Optical coherence tomography revealed atrophy of inner retinal layers and attenuation and disruption of the ellipsoid zone.
Crucially, the retina of the transplanted eye responded to light as confirmed by serial electroretinography. MRI scans demonstrated the integrity of the transplanted visual pathways and potential occipital cortical response to light stimulation of the transplanted eye. However, after one year, no light in the eye was observed by the patient.
As discussed in an accompanying editorial published in JAMA Network, whole eye transplantation (WET) has been regarded as one of the most difficult yet important transplant procedures to attempt developing. In 1978, a report from the National Eye Institute advisory stated that “[a]t present, any effort to transplant a mammalian eye is doomed to failure by the ganglion cell axon’s inability to withstand cutting, by the difficulty of insuring adequate circulation of blood to the transplanted eye during or shortly after operation, and lastly by immune rejection of foreign tissue.”
With this transplant case, the issues of adequate circulation and immune rejection have now been shown to be surmountable, the authors point out. Other issues to address concern connecting the cranial nerves to enable opening of the eyelid.
