Eye from organ donor ‘brought back to life’ by scientists

Breakthrough discovery gives scientists hope for future therapies for sight loss, reports Aisha Rimi

Scientists onducted experiments in the dark as she exposed donor eye tissue to different kinds of light and recorded photoreceptor responses (John A. Moran Eye Center at the University of Utah)

Scientists have managed to wake up light-sensing cells in eyes from dead organ donors, a discovery which could help the development of treatments to improve vision.

Photosensitive neuron cells in the retina were able to respond to light and communicate with each other up to five hours after death, sending signals “resembling those recorded from living subjects”.

These neurons form part of the central nervous system (CNS), which includes the brain and spinal cord, suggesting that other cells in the CNS could be similarly restored and could bring back consciousness.

Scientists designed a special transportation unit that could restore oxygen and other nutrients to the eyes as soon as they were removed from the donor. Initial experiments saw scientists being able to revive the light-sensing cells, but they couldn’t get them to talk to each other due to a lack of oxygen.

The authors of the study, writing in the journal Nature, said: “We were able to wake up photoreceptor cells in the human macula, which is the part of the retina responsible for our central vision and our ability to see fine detail and colour.

“In eyes obtained up to five hours after an organ’s death, these cells responded to bright lights and even very dim flashes of light.”

The new findings go a step further than a 2019 Yale University study, in which scientists restarted the brains of 32 decapitated pigs slaughtered hours earlier.

Dr Frans Vinberg, an assistant professor of ophthalmology and visual sciences at the University of Utah, said: “In Yale’s case, coordinated population activity of neurons in pig brains could not be revived.

“In our case, we were able to revive population responses from photoreceptor cells even up to five hours after death in the human central retina, an important part of our central nervous system.

“We were able to make the retinal cells talk to each other, the way they do in the living eye. Past studies have restored very limited electrical activity in organ donor eyes, but this has never been achieved in the macula, and never to the extent we have now demonstrated.

“Retina is part of our central nervous system so we think similar things might be seen also in the other parts of the brain.”

Researchers are hopeful the breakthrough will speed up new therapies for sight loss and improve the understanding of neurodegenerative diseases.