Purpose:
To compare changes in the corneal endothelium after deep lamellar endothelial keratoplasty (DLEK) with changes after penetrating keratoplasty (PK).
Methods:
Patients with endothelial dysfunction and corneal edema were randomized to DLEK (n=11) or PK (n=14). In vivo confocal microscopy was used to examine the transplanted corneal endothelium at 1, 3, and 6 months after surgery. Endothelial cell density (ECD), coefficient of variation of cell area (CV), and the percentage of hexagonal cells (%Hex) were measured by using the "corners method" on digital images of the endothelium. Preoperative donor ECD was obtained from the eye bank and the percentage loss in ECD from preoperative was calculated for each transplant. Metrics at each observation after surgery were compared between groups by using rank–sum tests adjusted for 3 comparisons (Bonferroni). Minimum detectable differences between groups (MDD, α=0.05/3, ß=0.2) were calculated for non–significant differences.
Results:
Preoperative ECD did not differ between DLEK (2747±388 cells/mm2) and PK (2858±322 cells/mm2, p=0.45) groups (mean±SD). ECD after surgery decreased from preoperative, but the percent loss did not differ between DLEK and PK at any time (p = 1.0, Table). CV and %Hex did not differ between the groups at any postoperative time. Three subjects within the DLEK group and none within the PK group required graft repositioning; cell losses in repositioned grafts and those not repositioned are given in the table (p > 0.33).
Conclusions:
Endothelial cell loss does not occur at grossly different rates during the first six months after DLEK or PK. Cell loss may be increased after a DLEK graft is repositioned.
Keywords: cornea: endothelium • transplantation • cell survival