A human donor retina has been shown to respond to light up to five hours after death, providing scientists with a new way to study retinal function outside the body. The advance is intended for research and does not restore sight or represent an eye transplantation procedure.
Researchers also recorded a B wave from the human macula after death, an electrical signal associated with retinal activity. The result offers a closer look at how light signals are processed in human retinal tissue.
The work was conducted by a team at the John A. Moran Eye Center at University of Utah Health and was published in Nature. The researchers examined data from more than 40 human donor eyes.
A System Designed to Preserve Retinal Function
The research relies on a dedicated transport unit that maintains oxygen and nutrient supplies for donor eye tissue. A separate stimulation device then delivers light while recording electrical responses from retinal cells.
Eyes were collected less than 20 minutes after death, allowing the tissue to be handled while it remained in a better-preserved condition. This rapid process was important for evaluating how long the retina could retain its responsiveness.
| Research Step | Reported Condition | Research Significance |
|---|---|---|
| Donor eye collection | Less than 20 minutes after death | Supports better tissue preservation |
| Macular photoreceptor response | Up to five hours after death | Responses remained detectable under several light stimuli |
| B wave recording | After oxygen and nutrients were supplied | Shows electrical activity in the human macula |
Oxygen Restored Cell-to-Cell Communication
In early experiments, the team could reactivate photoreceptors, the cells that detect light. Those cells initially did not communicate with one another as they would in living retinal tissue.
The researchers identified insufficient oxygen as the main reason for the loss of communication between cells. Once oxygenation and nutrient delivery were improved, the retina showed electrical activity resembling that of living tissue.
The human donor retina was able to respond to bright light, colored light, and very dim flashes in the macular region. Fatima Abbas, PhD, the study’s lead author, highlighted these responses as an opportunity to examine human light processing more directly.
Why the Macula Matters
The macula is a central area of the retina and a major focus of vision research. Its preserved responses may help scientists investigate cellular changes linked to retinal disease using human tissue rather than relying only on animal models.
The method could support research into age-related macular degeneration and other retinal conditions. However, it remains a laboratory approach for studying tissue function, not a treatment that patients can receive.
Researchers also believe the strategy of sustaining oxygen and nutrients could be useful for studying other tissues in the central nervous system. That possibility may broaden research into neurodegenerative disease while keeping the immediate focus on retinal biology.
