Comparison Of Diabetes Mellitus And Healthy Eye Donors On The Outcomes And Complications Of Corneal Transplantation: A Systematic Review

Corneal transplantation is a treatment noted for its high success rate. The success of the procedures may depend on several factors, including the donor status, surgical procedure, and underlying disease. Due to the growing population of diabetic patients, It is estimated approximately 30% of corneal transplant donors will be diabetic patients. Diabetes mellitus (DM) alters all layers of the cornea, including the epithelium, stroma, endothelium, and the nerve. As diabetic and healthy donors have varied corneal quality, this systematic review was conducted to determine how the diabetic donor status affects the outcomes and complications of corneal transplantation.

A systematic review from databases including PubMed, Ovid Embase, Cochrane, and Web of Science.

We systematically searched PubMed, Ovid Embase, Cochrane, and Web of Science databases up to January 2025, for studies comparing outcome and complications of diabetic versus non-diabetic donors. We included English-language clinical trials and randomized control trial studies investigating corneal transplantation procedures including penetrating keratoplasty (PKP), descemet membrane endothelial keratoplasty (DMEK) and descemet stripping automated endothelial keratoplasty (DSAEK). The main outcome parameters were endothelial cell density (ECD), 3-year graft survival, rebubbled graft numbers, air injection rate, best corrected visual acuity (BCVA) and tissue preparation success rate. 

A total of  7226 eyes from six studies were included, with three trials evaluating DSAEK, two DMEK, and one PKP.  33.6% of included eyes were those of diabetic donors. The age was between 12-90 years old with 52.77% female patients and follow up ranging from 1 day to 10 years. The most common underlying condition diagnosed in recipients was Fuchs Keratopathy. In DSAEK trials, recipients with DM donors had significantly lower ECD and 3-year graft survival. In DMEK trials, statistical significance was not shown with regards to rebubbled graft numbers, air reinjection rate and BCVA. In the PKP trial, ECD was evaluated which was not statistically different in DM donors.

The results for DM donors differed from those for healthy eyes following corneal transplant operations. Compared to normal donors, DM donors resulted in a shorter graft survival and a greater loss of endothelial cells.