Descemet Membrane Endothelial Keratoplasty: Comparison of Endothelial Cell Loss of Re-Bubbled Donor Grafts Versus Grafts Not Re-Bubbled
Purpose
To determine if the endothelial cell loss postop is different between Descemet membrane endothelial keratoplasty (DMEK) grafts that received an injection of air (re-bubble) post op compared to those grafts that did not.
Methods
Single center, single standardized technique of DMEK surgery performed for Fuchs’ dystrophy. (glass injector, SF6 gas bubble, eye bank pre-stripped tissue) All eyes with 6-month postop specular measurements of central endothelial cell density (ECD) were analyzed. Percentage endothelial cell loss (ECL) was determined by subtracting 6 months ECD from donor preop ECD and dividing by preop ECD. ECL was compared between eyes that were re-bubbled and eyes that did not receive a re-bubble with statistical analysis by students t-test.
Results
69 DMEK cases had cell counts available at 6 months. There were 63 cases without re-bubble and 6 cases that had a re-bubble of air for partial graft separation. No case required two re-bubbles. Re-bubble cases had a mean ECD at 6 months of 1709 +/- 329 representing a cell loss of 33+/- 14%. Cases that did not require a re-bubble had a mean ECD at 6 months of 2012 +/- 483 representing a cell loss of 26 +/- 16%. There was no statistical difference between the percentage cell loss of DMEK cases re-bubbled and those that were not. (p=0.32)
Conclusion
Unlike DSAEK where a re-bubble is usually done for a free floating graft and results in higher cell loss at 6 months postop, a re-bubbling event in DMEK surgery is done for partial separations and does not appear to result in a greater loss of endothelial cells.