Evidence of Donor Corneal Endothelial Cell Migration From Immune Reactions Occurring After Descemet Membrane Endothelial Keratoplasty

Purpose: The migratory capacity of donor corneal endothelial cells after Descemet membrane endothelial keratoplasty (DMEK) is not fully understood. We report 2 patients who developed immune reactions after DMEK with endothelial precipitates detectable not only on the grafts but also on host corneal areas stripped off the host Descemet membrane during surgery and initially not covered by the donor Descemet membrane and endothelium (naked stroma), strongly suggesting that migration of donor-derived endothelial cells had occurred. Methods: Observational case series of 2 patients. Results: A 71-year-old man (case 1) and an 84-year-old man (case 2)with Fuchs endothelial dystrophy underwent successful DMEK surgery. Postoperatively, the peripheral corneal stroma showed a denuded area that was not covered by the DMEK graft or by the patients' residual Descemet membrane (because of large descemetorhexis and slight graft decentration). After 18 (case 1) and 6(case 2) months, a diffuse endothelial immune reaction with precipitates on the graft and, surprisingly, also on peripheral corneal areas that were initially denuded of the host Descemet membrane and not covered by the donor Descemet membrane was observed. The outermost corneal parts covered by the patients' own residual Descemet membrane showed no precipitates. Under treatment with topical corticosteroids, the precipitates rapidly disappeared. Visual acuity, central corneal thickness, and endothelial cell counts were not significantly affected. Conclusions: The immune reaction episodes in our patients with endothelial precipitates detectable on adjacent host areas initially stripped off and not covered by donor Descemet membrane provide direct in vivo evidence of donor corneal endothelial cell migration after DMEK, filling areas of naked stroma.