Eye Transplantation Could Become a Reality

Researchers have developed a 3D-printed device called Eye-in-a-Care-Box (EcaBox) that preserves whole eyeballs by circulating an oxygen-rich solution around the eye. The system pumps the solution into the eye through a flexible tube inserted into the main artery and uses sensors to continuously regulate flow and pressure, according to IFLScience.

Experiments have shown that the new device can dramatically extend the survival of eyes outside the body. It even enabled pig eyes to continue transmitting electrical signals for more than 10 hours after death. Scientists believe that Eye-in-a-Care-Box could one day help make functional eye transplantation a reality.

Unlike heart, lung, or kidney transplants, a successful transplant of a functioning eye has never been achieved in humans, Focus reports. One of the main challenges is the retina, an extremely delicate tissue that is highly vulnerable to even brief interruptions in oxygen supply.

In 2024, surgeons performed a groundbreaking operation in which they transplanted part of a man's face along with a new left eye after he suffered a severe electrical injury. Although vision could not be restored, the transplanted retina responded to light and regained blood flow through a process known as reperfusion.

Inspired by this progress, researchers at the Barcelona Institute of Science and Technology in Spain developed the new preservation device. They initially tested it using pig eyes that were removed, placed on ice, and transported to the laboratory within 2.5 hours after death. Some of the eyes were preserved in the Eye-in-a-Care-Box, while others were stored in open air at 4°C. After 24 hours, the eyes kept in the device remained significantly more viable than those stored under conventional conditions.

During the experiments, the researchers observed fluid flowing through the blood vessels in 90% of successfully cannulated eyes. Microscopic examination confirmed that circulation reached not only larger vessels but also capillaries and tiny microvessels.

The team also used electroretinography (ERG), which measures the retina's electrical response to light. The results showed that 15 of the 36 perfused pig eyes continued responding to light while inside the device, in some cases for up to 10 hours after death. When perfusion was stopped, the electrical signals weakened, indicating that the oxygen supply was essential for maintaining retinal viability and light sensitivity.

The researchers also conducted several experiments on 12 human eyes obtained from six deceased donors. As with the pig eyes, the perfused human eyes were preserved significantly better than the control samples. However, it remains unclear whether they retained the light responses observed in the pig experiments.

The scientists hope their breakthrough will eventually make eye transplantation possible. In addition, they believe the Eye-in-a-Care-Box could serve as a valuable research platform for studying eye diseases and developing treatments for degenerative retinal disorders.

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