New Research Supports the Safety and Efficacy of Corneal Transplants (Keratoplasty) Irrespective of Donor Diabetes Status

UH Research & Education Institute

New research led by investigators at the Vision Research Coordinating Center (VRCC) and the Cornea Image Analysis Reading Center (CIARC) at University Hospitals Eye Institute and Case Western Reserve University (CWRU) potentially widens the donor pool for corneal transplant patients.

The research published October 17, 2025 in JAMA Ophthalmology and presented at the national meetings in Orlando, FL at the Cornea and Eye Banking Forum of the Cornea Society and Eye Bank Association of America and the Cornea Subspecialty Day of the American Academy of Ophthalmology, found that one- year outcomes for patients who received corneas from donors with diabetes did not differ significantly from those without disease.

“Many eye banks do not accept corneas from donors with diabetes, fearing they could compromise transplant outcomes,” says Jonathan Lass, MD, the Charles I Thomas Professor in the Department of Ophthalmology and Visual Sciences at CWRU School of Medicine, Distinguished Attending Surgeon in the University Hospitals Eye Institute, and the study’s lead researcher. “Our research strongly implies that the number of corneas available for transplant worldwide could be significantly increased with these findings.”

Transformative Eye Research Lays the Groundwork for Helping More Patients

Funded by the National Eye Institute (NEI), part of the National Institutes of Health, the randomized clinical trial, the Diabetes Endothelial Keratoplasty Study (DEKS), involved 1,097 patients who underwent Descemet Membrane Endothelial Keratoplasty (DMEK), a partial corneal transplant surgery that replaces diseased innermost layers of the cornea, the Descemet's membrane and endothelium, with healthy donor tissue to restore clarity and reduce blurry or distorted vision.

One third of the patients received corneas from donors with diabetes and two thirds from individuals from donors without the disease. The outcomes for patients who received transplants from donors with or without diabetes were comparable, without any significant differences noted between the patient groups one year after the DMEK surgery was completed.

According to Dr. Lass, the severity of a donor’s diabetes also did not affect transplant outcomes and the corneal structure remained healthy across all patient groups.

With these findings eye banks can offer the full spectrum of diabetes donors for transplant, if they otherwise meet all other donor eligibility requirements, says Dr. Lass. In the past, many eye banks did not use diabetic donors for DMEK, the leading keratoplasty procedure now in the United States representing more than 18,000 procedures in 2024, according to the Eye Bank Association of America Annual Statistical report.

The DEKS study involved donated corneas from 13 eye banks in the United States, representing 1,154 donors for 1,421 DMEK procedures, 28 clinical testing sites and 46 surgeons.  The study was coordinated by the UH VRCC led by Loretta Szczotka-Flynn, OD, PhD, Searle-Huang Professor of Ophthalmology, CWRU and Director of the Contact Lens Service at University Hospitals Cleveland Medical Center.  Ahmed Omar, MD, PhD, Clinical Assistant Professor, CWRU and head of the Cornea Service at UH served as the PI enrolling UH patients in the study at UH.

Simultaneously, researchers tracked what happened to the transplanted corneal endothelial cells following the DMEK procedure. These cells are vital to pumping fluid out of the cornea and keeping it clear, but once they are lost, they cannot be replaced naturally.

In their study, they found that endothelial cell loss one year after surgery was 28%, whether a donor had diabetes or not, says Beth Ann Benetz, MA FOPS, CWRU Professor of Ophthalmology and Scientific Director of the CIARC.

The findings provide data that reassures eye banks that individuals with diabetes can be cornea donors, increasing the number of patients who can benefit from corneal transplants. Moving forward, the NEI has agreed to support studying participants out five years from their surgeries to validate the findings of the DEKS long term.

Leveraging Center Expertise and Transforming the Ophthalmology Field Worldwide

Image analysis for the NEI study was completed by the CIARC at UH and CWRU. The center has a long history of delivering expert, standardized image grading and analysis support to assess the effects of drugs, devices, diseases and procedures on the anterior segment.

Including the DMEK study, the CIARC has led and served as a reading center exploring important questions in keratoplasty and eye banking including three NEI-funded randomized controlled trials since 2000 including the Cornea Donor Study (CDS), the Cornea Preservation Time Study (CPTS), and now the DEKS, the Descemet Endothelial Thickness Comparison Trial (DETECT) with investigators at Stanford, and the Department of Defense funded study, Ex Vivo Corneal Crosslinking for Vascularized High-Risk Keratoplasty (ExCrossV), a collaborative study with Harvard investigators.. These studies have established a vast amount of clinical evidence, addressing donor and donor tissue characteristics, donor tissue storage and operative and post-operative factors supporting endothelial cell health and optimal patient outcomes, thereby directly impacting and advancing eye banking and keratoplasty (corneal grafting) practices globally.

The CIARC with their collaboration with David Wilson, PhD in the Biomedical Engineering Department at CWRU was recently awarded a High Impact Grant from the Eye Bank Association of America to advance their work on developing software for the automated analysis using AI analysis methods of the number of donor endothelial cells to be transplanted provided by the eye bank, a key parameter for donor tissue eligibility. If successful, this software could provide a more efficient, accurate and comprehensive determination of the number of endothelial cells with the donor tissue advancing keratoplasty outcomes.