The human eye is a very complex organ. Some of its talents lie in its complexity, but it is the source of problems and examining eyes is no easy task. This means, for example, that the eye is one of the organs that we cannot transplant. That may one day change, and a group of scientists has achieved that the retinal cells of a deceased person can “see” light. The new study, published in the journal Nature, gives us new clues about life and death in and outside of this unique organ.

Origin: Pig brain.
The origin of the study was related to a previous experiment in which scientists managed to keep pig brains alive after death. The scientists leading this experiment explain that it inspired them to try something similar on the human eye.

Human retina.
And human retinas are part of both the eye and the central nervous system, so what was learned in the first experiment could be very useful. Ocular work was carried out specifically in the photoreceptor cells of the macula, the part of the retina associated with central vision and the vision of colors and details. According to the study’s author, University of Utah biomedical expert Fatima Abbas, the experiment achieved its goal of “waking up” these cells after death.

What happens after death (in the eyes)?
Initial tests were able to reactivate these photoreceptors, but the team wanted to go further, they wanted these cells to communicate. For this, they had to ask themselves what is it that does not allow cells to function after death.

They found that the phenomenon affecting the experiment was hypoxia, or lack of oxygen. Therefore, they tried to minimize the time between the death of the donors and the study. With this, they were able to record, for the first time, the so-called “Wave b” signal emitted by these photoreceptors in the eye of a deceased person.

Between life and death.
In short, resurrected photoreceptors are neurons that add a new dimension to working outside the visual field. The authors not only note that the work may have applications in other areas of the central nervous system, but also question the current concept of death as a process triggered by irreversible loss of neuronal activity.

I give you my eyes.
Eye transplants are not possible today, but this research could help improve retinal transplants, which are currently a very limited procedure. However, there is still a long way to go to get there. Perhaps these advances will alleviate the intriguing barriers that patients with vision problems may face.

Improve the work of the eyes.
For now, the study’s authors point out that it will allow for progress in the study of the eye and vision. One problem faced by researchers in this field stems from the differences between the human eye and the animal eye, which are often used in medical studies. In addition, brain death affects existing neurons in the eye, making it difficult to study the retina in the human eye. It may even help us understand a little better what is on the border between life and death.

Image | Victor Freitas