Impact of donor tissue diameter on postoperative central endothelial cell density in Descemet Membrane Endothelial Keratoplasty.

PURPOSE: To assess the effect of donor tissue diameter in Descemet Membrane Endothelial Keratoplasty (DMEK) on postoperative endothelial cell density (ECD) mainly in Fuchs Endothelial Corneal Dystrophy (FECD) patients.

METHODS: Retrospective review of 693 consecutive DMEK surgeries from the prospective Cologne DMEK database performed between 07/2011 and 07/2016 at the Department of Ophthalmology, University of Cologne. Eight- versus ten-millimetre large donor DMEK grafts of two different surgeons using identical surgical techniques were compared.

RESULTS: A total of 693 consecutive DMEK surgeries were included. Two groups (8 versus 10 mm DMEK graft diameter) were compared: 23% of eyes received 8-mm grafts (group 1, n = 160) and 77% 10-mm grafts (group 2, n = 533). Mean preoperative ECD (±SD) of donor tissue was 2736 ± 224 cells/mm2 in group 1 and 2714 ± 232 in group 2. Group 1 showed a mean ECD of 1740 ± 439 cells/mm2 (mean ± SD; n = 67) 12 months after DMEK compared to 1664 ± 404 cells/mm2 (mean ± SD; n = 344) in group 2. The difference between the 6- and 12-month ECD of both groups was not significant (p = 0.675; p = 0.161). Total decrease in ECD 6- and 12-months postoperatively was 38 ± 14 (n = 128) and 36 ± 16% in group 1 (n = 66) versus 37 ± 15% (n = 398) and 38 ± 15% in group 2 (n = 342; p = 0.414; p = 0.198, respectively).

CONCLUSION: Our data suggest that postoperative central endothelial cell density is not significantly associated with DMEK graft diameters in the range of 8-10 mm in cases with healthy peripheral host endothelium (such as FECD).