A team at the Centre for Genomic Regulation in Barcelona has built a sealed, perfused chamber that keeps a removed eye supplied with oxygenated fluid through its main artery, in an attempt to slow the retinal degeneration that has, so far, made whole-eye transplantation a procedure that restores an eye’s appearance and blood flow but not a patient’s sight. The device, which the team calls the Eye-in-a-Care-Box, or ECaBox, has been tested mainly on pig eyes obtained from a slaughterhouse, along with a small number of human donor eyes.
The work, led by Pia Cosma at the Centre for Genomic Regulation, part of the Barcelona Institute of Science and Technology, is described in a preprint posted to bioRxiv on 25 June 2026. It has not yet been peer-reviewed. This is one preprint from one laboratory, not a validated finding, and the distinction matters more here than usual, because the practical stakes, real eye transplants, are high enough that the gap between a promising preprint and a working clinical procedure is worth keeping in view throughout.
What the device does
The problem ECaBox is built to address is specific: the retina, the light-sensing tissue lining the back of the eye, begins deteriorating almost as soon as its blood supply is cut, and once that deterioration progresses far enough, the eye loses the ability to respond to light at all, regardless of how well the rest of the organ is preserved. Reporting by MIT Technology Review describes the device as working through perfusion, a technique already used to preserve other transplant organs by supplying them with some of the oxygen and nutrients they would normally receive from circulating blood. In the ECaBox, the eye rests on a bed inside a sealed chamber that controls temperature and pressure, fluid is pumped in through the ophthalmic artery and drained away, and a viewing window lets researchers monitor the tissue without opening the chamber.
Cosma’s team first compared perfused pig eyes against two alternatives: pig eyes left at room temperature, and pig eyes refrigerated at 4 degrees Celsius, a standard cold-storage approach used for some donor tissue. Neither alternative held up. Cells in the room-temperature eyes shrank and the tissue lost structure quickly; the refrigerated eyes degenerated within 24 hours despite the cold. Eyes maintained in the ECaBox were, in the team’s own assessment reported to MIT Technology Review, “significantly more viable” after the same 24-hour window.
The light response, and its limits
The more striking result concerns electrical activity. Of 36 pig eyes perfused in the device, 15 continued producing electrical responses to light for up to ten hours after death, according to Vice’s coverage of the preprint. Untreated pig eyes lost the ability to respond to light as soon as they were removed from the animal; in perfused eyes, that response returned after roughly 15 minutes on the device, and faded again once the oxygenated flow was switched off. The researchers characterise this as evidence that perfusion keeps retinal tissue functionally alive, at least in the narrow sense of retaining the capacity to convert light into an electrical signal.
Fifteen out of 36 is worth sitting with. Less than half of the perfused eyes sustained a light response out to the ten-hour mark, and the preprint, as reported, does not appear to establish why some eyes responded for that long while others did not. This is a real effect in a specific experimental setup, not a demonstrated reliability rate for any future clinical use of the device.
What happened with human eyes
The team also tested the ECaBox on 12 eyes recovered from six human donors after death, using a paired design: one eye from each donor went into the device, the other did not. The perfused human eyes showed better retinal preservation than their unperfused counterparts, mirroring the pig result. The researchers did not, however, measure whether the perfused human eyes retained a light response, which means the central finding from the pig experiments, sustained electrical activity for hours after death, has not yet been replicated in human tissue. What has been shown in humans so far is structural preservation of the retina, not functional light responsiveness.
Why an eye responding to light is not the same as an eye that can see
Shannon Tessier, a researcher at Massachusetts General Hospital who studies organ perfusion and was not involved in the work, told MIT Technology Review the result “could be a new frontier for retina preservation,” while also cautioning that the practical question, whether an ECaBox-treated eye would actually restore vision once transplanted, cannot be answered by preservation data alone. “We won’t know whether eyes treated in the ECaBox could do any better until they have been transplanted,” she said.
That caution lines up with the field’s recent clinical experience. In May 2023, a team at NYU Langone performed the first whole-eye and partial face transplant, on a man who had lost the left side of his face, including his left eye, in a high-voltage accident. The transplanted eye retained blood flow and the patient recovered well overall, but he did not regain sight in the transplanted eye. Restoring circulation and structural viability to a donor eye, in other words, has already been achieved surgically, and it did not produce a seeing eye. The obstacle that remains, connecting a functioning retina back to the optic nerve and, through it, to the brain’s visual processing, is not something a perfusion device addresses by itself.
What the researchers say comes next
Cosma and her colleagues describe plans, in the preprint, to build a portable, surgery-room version of the ECaBox, intended to begin perfusing donor eyes as soon as possible after death, including eyes from heart-beating donors when they become available, to minimise the degradation that sets in during the gap between death and laboratory perfusion. That is a stated intention rather than a completed step, and the preprint has not yet gone through peer review. The team’s stated aim for the device is twofold: a research tool that could reduce researchers’ reliance on animal experimentation for studying eye disease and treatments, and, further off, a step toward donor eyes that might be viable for whole-eye transplantation.
Whether either goal is reached will depend on work well beyond what a sealed box of oxygenated fluid can do on its own. The retina responding to light in a chamber in Barcelona is a necessary condition for a transplanted eye to see again. On the evidence published so far, it is not yet a sufficient one.