Endothelial Cell Density to Predict Endothelial Graft Failure After Penetrating Keratoplasty

Objective: To determine whether preoperative and/or postoperative central endothelial cell density (ECD) and its rate of decline postoperatively are predictive of graft failure caused by endothelial decompensation following penetrating keratoplasty to treat a moderate-risk condition, principally, Fuchs dystrophy or pseudophakic corneal edema. Methods: In a subset of Cornea Donor Study participants, a central reading center determined preoperative and postoperative ECD from available specular images for 17 grafts that failed because of endothelial decompensation and 483 grafts that did not fail. Results: Preoperative ECD was not predictive of graft failure caused by endothelial decompensation (P=.91). However, the 6-month ECD was predictive of subsequent failure (P<.001). Among those that had not failed within the first 6 months, the 5-year cumulative incidence (+/- 95% confidence interval) of failure was 13% (+/- 12%) for the 33 participants with a 6-month ECD of less than 1700 cells/mm(2) vs 2%(+/- 3%) for the 137 participants with a 6-month ECD of 2500 cells/mm(2) or higher. After 5 years' follow-up, 40 of 277 participants (14%) with a clear graft had an ECD below 500 cells/mm(2). Conclusions: Preoperative ECD is unrelated to graft failure from endothelial decompensation, whereas there is a strong correlation of ECD at 6 months with graft failure from endothelial decompensation. A graft can remain clear after 5 years even when the ECD is below 500 cells/mm(2).