A landmark clinical investigation has determined that corneas from donors with diabetes are just as effective for transplantation as those from non-diabetic donors, a finding that could significantly expand the global pool of available tissue for sight-restoring surgeries. The federally funded study challenges long-held conventions in tissue selection and promises to reduce waiting times for patients suffering from diseases of the corneal endothelium.
Published in JAMA Ophthalmology, the research dispels persistent concerns that tissue from diabetic donors could lead to accelerated cell loss or lower success rates for transplants. By providing strong evidence to the contrary, the study encourages eye banks to revise their donor eligibility criteria, potentially making thousands of additional corneas available for transplant procedures annually and increasing access to care for patients worldwide.
Addressing a Global Need
Corneal disease is a leading cause of blindness, affecting millions of people globally. The primary treatment for restoring vision is a corneal transplant, which relies entirely on tissue from deceased donors. However, there is a significant international shortage of donor corneas, with an estimated 10 million people in need of this sight-saving surgery. This scarcity is compounded by restrictive donor eligibility criteria that often disqualify tissue based on a donor’s medical history or age.
In many countries, including the United States, eye banks have historically set arbitrary upper age limits, often around 65 years, due to surgeons’ reluctance to use tissue from older donors. Similarly, tissue from individuals with systemic diseases like diabetes has often been excluded over fears of inferior quality. These practices have limited the number of available grafts, leaving many patients with prolonged vision loss. The new research directly confronts these paradigms by providing robust scientific evidence that many of these exclusions are unnecessary.
The Diabetes Endothelial Keratoplasty Study
The Diabetes Endothelial Keratoplasty Study (DEKS), funded by the National Eye Institute, was a large-scale clinical trial designed to resolve the debate over using corneas from diabetic donors. The study was led by researchers at Case Western Reserve University and involved a collaborative effort across numerous medical centers and eye banks. It represents a significant step forward in evidence-based standards for tissue donation.
Methodology and Scope
Investigators in the DEKS trial tracked the outcomes of more than 1,400 corneal transplant procedures. These surgeries were performed by 46 different surgeons at 28 medical centers throughout the United States, ensuring a broad and diverse dataset. The study included tissue sourced from 13 separate eye banks, which provided clinical expertise and donor corneas from individuals both with and without a history of diabetes. The primary outcome measured was the success rate of the transplant one year after surgery, with a focus on the health and density of the crucial endothelial cells that keep the cornea clear.
Key Findings
The results of the study were decisive: investigators found no statistically significant difference in transplant success rates at the one-year mark between patients who received corneas from diabetic donors and those who received tissue from non-diabetic donors. This outcome demonstrates that a donor’s diabetes status does not negatively impact the short-term viability of the corneal graft. The findings provide the first large-scale, clinical evidence to support a policy change, affirming that these corneas are safe and effective for transplantation procedures such as Descemet membrane endothelial keratoplasty (DMEK).
Implications for Patients and Practitioners
The conclusions drawn from this research have transformative potential for clinical practice. By scientifically validating the use of corneas from diabetic donors, the study paves the way for eye banks to confidently and immediately expand their donor criteria. Michael Titus, Senior Vice President of Clinical Operations at Eversight, an organization that participated in the study, noted that the evidence “has the potential to expand access to sight-restoring surgery for thousands of people around the world.” This expansion is critical for reducing patient wait times and addressing the backlog of individuals needing treatment for conditions like Fuchs’ endothelial dystrophy.
For surgeons, the study offers assurance that they can use tissue from a wider range of donors without compromising patient outcomes. This flexibility is especially important for advanced, selective-layer transplantations where the quality of the endothelial cell layer is paramount. By removing a long-standing barrier to donation, the research empowers both eye banks and surgeons to serve a larger patient population more efficiently.
Expanding Age Limits and Future Research
The re-evaluation of donor criteria is not limited to diabetes. Other recent research has explored expanding the upper age limit for cornea donors. A retrospective case series published in the journal Cornea found that tissues from donors aged 76 to 80 were safe and effective for transplantation. The study reported a suitability rate of 57% for this older group, which was not significantly different from the 59% rate for donors aged 71 to 75. Such findings, combined with the DEKS results, signal a broader shift toward more inclusive donation standards based on tissue quality rather than arbitrary demographic limits.
While the DEKS study provides a definitive one-year analysis, further research may follow to confirm long-term outcomes beyond the initial post-operative period. Researchers also continue to explore innovative solutions to the donor shortage, such as tissue engineering. Scientists are developing methods to grow corneal endothelial cells in a laboratory, potentially using a patient’s own cells or stem cells to create custom grafts. This technology could one day eliminate the need for human donor tissue entirely, offering a nearly unlimited supply for transplants and overcoming the challenge of immune rejection.
