Intraoperative Cell Death Signs In Corneal Graft With Subsequent Graft Detachment And Rebubbling Procedure After Triple Dmek Surgery

To report the occurrence of apoptosis signs in a corneal graft during preparation for Descemet Membrane Endothelial Keratoplasty and intraocular lens implantation (triple DMEK) in a 65-year-old woman with Fuchs' Endothelial Dystrophy (FED) who developed graft detachment in the postoperative course with the necessity of rebubbling two weeks after surgery.

University Hospital, Ludwig-Maximilians-University (LMU), Department of Ophthalmology, Munich, Germany.

We describe the case of a 65-year-old phakic woman with FED who received a triple DMEK. No other ocular disease was known and initial best corrected distance visual acuity (BCVA) was 0.20 logMAR.  

Graft preparation was conducted by the surgeon immediately before transplantation using a corneal transplant from an external tissue bank with an endothelial cell density (ECD) of 2360 cells/mm². The graft was prepared using a no touch liquid bubble dissection technique and subsequently loaded into a glass cartridge. At the beginning of preparation, the graft was stained with trypan blue which was also used for bubble dissection. The stain unmasked subtle signs of apoptosis which appeared fine and linear running radially from the periphery to the centre of the graft. Towards the end of preparation, those apoptotic areas presented as clear visible staining streets. During triple DMEK, the graft was then transplanted into the anterior chamber and stretched out with a no-touching technique by manipulating the cornea from the outside. SF6 gas tamponade was applied. There were no intraoperative complications.

Within two weeks after surgery, the patient developed relevant graft detachment including the central 4 mm zone and BCVA dropped down to 1.3 logMAR. Rebubbling was conducted using SF6 gas tamponade and full graft attachment was achieved with BCVA increasing to 0.10 logMAR. Three months after triple DMEK, BCVA was 0.10 logMAR and ECD was 977 cells/mm² with complete graft attachment.

Transplant quality and in particular an intact donor endothelium is a key requirement for successful DMEK surgery. In our case, the donor endothelium showed very subtle cell death signs at bare sight through the surgical microscope when first staining it at the beginning of preparation. Those apoptosis signs were enhanced by repeated trypan blue staining and clearly visible by the end of preparation. Since cell death only occurs after certain time and graft preparation consumes solely some minutes, the apoptotic areas must have already been in place. To what extend the described intraoperative apoptosis signs might represent a relevant indicator for postoperative transplant issues like graft detachment remains subject of further studies.