Descemet membrane endothelial keratoplasty (DMEK) seems to be the most promising technique for treating endothelium-related disorders of the cornea. However, graft detachment is a frequent complication. It often can be treated by rebubbling procedures. Unfortunately, this increases the risk of subsequent graft failure. It is therefore essential to define risk factors for graft detachment in DMEK. In this study, postoperative intraocular pressure (IOP) is investigated in this regard.
In total, 1047 DMEK procedures in patients with Fuchs endothelial dystrophy or bullous keratopathy were reviewed. All rebubbling procedures were recorded as well as postoperative IOP values (first measure 2 hours postoperatively and highest and lowest value within 3 days after surgery), donor factors (donor age, organ culture time, and endothelial cell count), and whether DMEK surgery had been combined with cataract surgery (triple-DMEK). Incidence rates were estimated with the Kaplan–Meier method. Cox regression was used to assess statistical significance.
The overall rebubbling rate was 24% after 8 weeks. Relative dips in IOP may be associated with a higher risk for graft detachment (hazards ratio = 0.41; P < 0.001). Graft detachment was neither significantly influenced by donor factors, first or maximum IOP, nor by simultaneous cataract surgery (triple-DMEK).
Avoiding dips in IOP may reduce the risk for graft detachment after DMEK. To prevent lowering of IOP values in the early postsurgical period, it may be advisable to achieve tight surgical wounds at the end of DMEK surgery and optimal filling of the anterior chamber with air and optionally with gas.