Incidence of Early Allograft Rejection After Descemet Membrane Endothelial Keratoplasty

Purpose: To report the incidence of early allograft rejection after Descemet membrane endothelial keratoplasty (DMEK), that is, transplantation of isolated Descemet membrane with its endothelium. Methods: The first series of 120 eyes of 105 patients operated on for Fuchs endothelial dystrophy or pseudophakic bullous keratopathy, with an average 2 years of follow-up after 9.0- to 10.0-mm-diameter DMEK, enrolled in our study. Results: During the entire study period, only 1 of the eyes showed any signs of a cellular immune response to the Descemet graft. A 76-year-old patient presented with discomfort, reduced visual acuity to counting fingers, corneal decompensation, and a Khodadoust line in the central cornea 4 months after (decentered) DMEK. Intensified topical corticoid therapy resulted in a complete visual recovery to 20/25 (0.8) within weeks. Conclusions: A classic allograft rejection (with an appearance similar to that after penetrating keratoplasty) can occur after DMEK. However, compared with the earlier (endothelial) keratoplasty procedures, DMEK may be associated with a lower rejection rate of <= 1%, despite transplant diameters of 69.5 mm. The apparent immune tolerance in DMEK may result from either less upregulation or more downregulation of the immune system.