DESCEMET MEMBRANE ENDOTHELIAL KERATOPLASTY WITHOUT INTRAOPERATIVE FLUID/AIR EXCHANGE AFTER A 100% AIR TAMPONADE

At the end of Descemet Membrane Endothelial Keratoplasty (DMEK), some surgeons leave a 100% air tamponade for about 30-60 minutes in the anterior chamber to promote graft attachment to the recipient’s corneal stroma (known as ´waiting time´). Thereafter, a fluid/air exchange is performed to reduce the air bubble to 30-50% before the patient leaves the operating room.

The aim of this study was to investigate the postoperative outcome after DMEK when no waiting time was performed, and air removal/reduction – if required - was considered at the slit lamp.

The study was performed as a retrospective analysis of the surgical cases at the Department of Ophthalmology of the University Hospital Muenster. 

In this retrospective analysis, 30 consecutive DMEK eyes of 30 patients were included, all of whom underwent DMEK without a waiting time and fluid/air exchange. All patients received a YAG-laser iridotomy one day prior to DMEK. If a pupillary block or increased intraocular pressure was observed on the day of surgery, air was removed from the anterior chamber through a paracentesis. The patients were monitored for signs of infection and graft detachment up to one month postoperatively.

Of the 30 eyes, 24 had Fuchs Endothelial Corneal Dystrophy, 4 had Pseudophakic  Bullous Keratopathy, one case was operated for DMEK failure and one for failure after Penetrating Keratoplasty (PK). Cataract surgery was combined with DMEK in 11 eyes, whereas 17 eyes were pseudophakic, and 2 eyes were phakic before surgery. All patients were examined at the slit lamp between 2 and 4 hours after DMEK. Air removal at the slit lamp was required in 50% of the eyes (n=15). This was due to a pupillary block (n=8), or an almost completely filled and deep anterior chamber with an elevated intraocular pressure (n=4) or normal intraocular pressure (n=3). A significant graft detachment requiring rebubbling, occurred in 3 eyes (10%). No intraocular inflammation could be detected within one month after DMEK.

Maintaining a 100% air tamponade at the end of DMEK increases the risk of pupillary block or an elevation in the intraocular pressure. Both can be resolved through timely air removal at the slit lamp without inducing an infection and without increasing the incidence of a significant graft detachment. A shorter intraoperative waiting period can reduce surgery time and may allow a more efficient utilization of surgical capacities.