Ultrastructural findings in graft failure after Descemet membrane endothelial keratoplasty (DMEK) and new triple procedure

摘要

To investigate factors that influence graft failure after Descemet membrane endothelial keratoplasty ( DMEK ) based on transmission electron microscopy results. Retrospective observational case series. This single center study included 16 eyes of 16 patients with penetrating keratoplasty (n = 14) or repeat DMEK (n = 2) following graft failure after DMEK . The main outcome measures were ultrastructural changes in the explanted graft on transmission electron microscopy , best-corrected visual acuity, and central corneal thickness. The mean preoperative and postoperative best-corrected visual acuity was 1.01 ± 0.54 logMAR and 0.56 ± 0.37 logMAR. The mean central corneal preoperative and postoperative thickness was 667 ± 187 μm and 511 ± 42 μm. Visual acuity and central corneal thickness improved significantly ( P = .001/ P = .003) after repeat surgery. Electron microscopy showed that 3 of 14 corneas showed upside down transplantation, and 3 corneas had pigmented cells or pigment granules at the Descemet–stroma interface. Further, 9 of 16 specimens showed a posterior collagenous layer deposited onto the Descemet membrane (average thickness 5.1 ± 6.2 μm; ranged 0.65–20 μm); this did not correlate significantly with the time between the original and repeat keratoplasty. Of 16 original grafts, 7 showed ultrastructural anomalies of the Descemet membrane , but one excised cornea showed no Descemet membrane pathologies. The majority of eyes with graft failure after DMEK showed ultrastructural changes in the Descemet membrane . It is crucial to assess donor tissue quality and to conduct graft marking before surgery to avoid immediate or delayed graft failure after DMEK . Nevertheless, repeat keratoplasty provided significant improvement in central corneal thickness and visual acuity.