Purpose: Intraocular pressure (IOP) elevation and post-keratoplasty glaucoma occur commonly after penetrating keratoplasty (PK), but also after Descemet stripping endothelial keratoplasty (DSEK). In this study, we evaluated the risk after Descemet membrane endothelial keratoplasty (DMEK) to develop IOP elevation and post-DMEK glaucoma.
Methods: The 12-month incidence of IOP elevation and post-DMEK glaucoma was analyzed retrospectively in the first 117 consecutive eyes that underwent DMEK between September 2011 and December 2012 at the Universitätsmedizin-Charité, Berlin. IOP elevation was defined as IOP ≥ 22 mmHg, or ≥10 mmHg from preoperative baseline. The assessment included the pre-operative history of corneal disease and glaucoma. Furthermore, the response to anti-glaucoma treatment, the graft failure, the IOP, the visual acuity, and the endothelial cell count were evaluated.
Results: The 12-month incidence of IOP elevation was 12.10 % [95 % confidence interval (CI): 0.94 %, 18.37 %], post-DMEK glaucoma 2.7 % (95 % CI: -0.44 %, 5.84 %). The most frequent cause remained steroid-induced IOP elevation, with an 12-month incidence of 8.0 % (95 % CI: 7.95 %, 8.05 %). In all cases, IOP elevation was treated effectively by tapering down steroid medication and initiating or increasing anti-glaucoma medication. The incidence of postoperative postoperative pupillary block IOP elevation was 15.40 % (95 % CI: 8.93 %, 21.87 %). The number of eyes with iridocorneal contacts after surgery was low (4.2 %). Only the preoperative increased IOP is a significant risk factor for IOP elevation (p = 0.005). Visual acuity improved significantly after surgery (p < 0.001), and clear grafts were achieved in all eyes. Mean endothelial cell count did not differ between patients with and without IOP elevation.
Conclusion: Incidence of IOP elevation and post-keratoplasty glaucoma after DMEK were low, but regular IOP measurements, especially in eyes with pre-existing glaucoma and bullous keratopathy, are necessary. Steroid-induced IOP elevation was the most frequent reason, and could be treated effectively by tapering down steroid medication or changing the steroid drug. Development of peripheral anterior synechiae after DMEK occured rarely. Therefore, the risk for IOP elevation and especially post-DMEK keratoplasty was reduced compared to PK and DSEK. In all cases, successful management by medical treatment was possible, and resulted in good visual acuity.