Vision scientists revive light-sensing cells in organ donor eyes

Scientists have revived light-sensing neurons in eyeballs acquired from post-mortem organ donors and restored their ability to interact in a succession of findings that could alter brain and vision research.

Many human organs can be transplanted from deceased donors, but central nervous system tissues quickly lose viability when circulation is interrupted and oxygen is depleted. This limits their potential utility.

The researchers utilised the retina as a model of the human central nervous system, which contains billions of neurons that carry sensory information as electrical signals, to investigate how neurons die and possible new treatments.

Lead author Fatima Abbas, a scientist at the John A. Moran Eye Centre at the University of Utah in the US, explains lead author Fatima Abbas, "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 donor’s death, these cells responded to bright light, coloured lights, and even very dim flashes of light."

The researchers were able to restore the photoreceptors in these early trials by restoring normal pH and oxygenation, but they appeared to have lost their ability to communicate with other retinal cells due to oxygen deprivation.

They devised a specific transportation unit to restore oxygenation and other nutrients to organ donor eyes in under 20 minutes after death, as well as another gadget that stimulates the retina and detects the electrical activity of its cells.

The researchers was able to recover an unique electrical signal seen in living eyes, known as the "b wave," using this method, and this is the first b wave recording obtained from the central retina of post-mortem human eyes.