Descemet membrane endothelial keratoplastydonor tissue preparation and clinical outcomes

Resumen

Corneal transplantation is being performed for treating corneal diseases, for relieving or taking away the pain and more important, for improving the clinical outcomes like visual acuity. In the past, patients with endothelial disorders were treated with penetrating keratoplasty by which the whole cornea, with all five tissue layers, was transplanted. This technique often presented some disadvantages like high astigmatism, long term unstable refraction, suture-related problems and ineffective wound healing. Furthermore, the visual rehabilitation was slow and the final outcome often disappointing. These disadvantages stimulated the development of other keratoplasty techniques like lamellar keratoplasty. With this technique it¿s possible to selectively replace the affected tissue layer of the cornea, improving the technique itself as well as the clinical outcomes. Although these (endothelial) keratoplasty (EK) techniques like ¿deep lamellar endothelial keratoplasty¿ (DLEK), ¿Descemet stripping (automated) endothelial keratoplasty¿ (DS(A)EK) and ¿femtosecond laser-assisted Descemet stripping endothelial keratoplasty¿ (FS-DSEK) improved the outcomes and reduced the undesired postoperative inconveniences and complications compared to the full thickness- or penetrating keratoplasty, visual results were still suboptimal. With previously described (endothelial) keratoplasty techniques a donor transplant, consisting from endothelium, the Descemet membrane AND part of the stromal tissue layer is transplanted. The extra stromal tissue may interfere with optimal visual results. This induced more research on the refinement in donor preparation and surgical techniques in endothelial keratoplasty, leading to the development of a new technique, named Descemet Membrane Endothelial Keratoplasty (DMEK). In DMEK only the affected two layers are replaced and this may provoke better and more optimal clinical results and offers a complete anatomical restoration. The focus of this thesis will be on DMEK, a new transplantation technique, of which the donor preparation technique, the clinical outcomes like visual rehabilitation, endothelial cell density, refractive change and stability, complications and new perspectives are described and compared to the earlier EK techniques.