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

Abstract

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).

Factors associated with endothelial cell density loss post Descemet membrane endothelial keratoplasty for bullous keratopathy in Asia

“…Although patients with BK should have few healthy endothelial cells in the peripheral cornea, most patients with FECD might have some healthy endothelium in the peripheral cornea [21]. This difference of healthy endothelium distribution between BK and FECD may be one of the reasons why the results of the current study differed from those of Schrittenlocher et al [17]. Although detailed knowledge regarding the migration of corneal endothelial cell is lacking, it is considered that corneal endothelial cells close the wound gap mainly via migration and increased cell spreading [22].…”

“…In contrast, Schrittenlocher et al reported that postoperative ECD was not significantly associated with DMEK graft diameters in the range of 8-10 mm in FECD eyes. [17]. Although many studies have evaluated graft size, no study has evaluated the ratio of graft to cornea area.…”

Outcomes of Descemet Membrane Endothelial Keratoplasty in Bangkok, Thailand

“… 14 Conversely, the study from Europe reported that postoperative ECD was not significantly associated with DMEK graft sizes in the range of 8–10 mm in FECD cases with healthy peripheral host endothelium. 36 This is likely due to smaller eyeballs with shallower anterior chambers in Asians, causing smaller graft sizes used in our study (7.0–8.5 mm) and Japanese study (5.0–8.5 mm). 14 More importantly, advanced FECD and bullous keratopathy account for higher proportion of EK cases in Asia.…”

Tips, Tricks, and Guides in Descemet Membrane Endothelial Keratoplasty Learning Curve

“…Corneal endothelial cell density (ECD) is higher in the periphery compared to the central cornea, especially beyond 9.00 mm [27,28]. Delivering larger grafts could theoretically not only provide a higher number of transplanted cells but also include an area containing cells with high proliferative potential, which could potentially increase graft survival [29][30][31].…”