Cornea Research Foundation of America, Indianapolis, IN 46260, USA.
Curr Opin Ophthalmol. 2013 Jul;24(4):329-35. doi: 10.1097/ICU.0b013e32836229ab.
Descemet's stripping endothelial keratoplasty (DSEK) is the most popular treatment for endothelial dysfunction, but Descemet's membrane endothelial keratoplasty (DMEK) now provides better vision with lower risk of immunologic rejection. Although DMEK is more challenging, advances in instrumentation and techniques are reducing the learning curve.
In contrast to DSEK, which includes posterior donor stroma, DMEK consists merely of donor endothelium and Descemet's membrane, so DMEK does not create a stromal interface and induces significantly less posterior surface aberrations, resulting in better vision. Furthermore, multiple centers report remarkably low (<1%) cumulative probability of immunologic graft rejection episodes through 2 years after DMEK. Initially, the biggest challenges were tissue loss in preparation and ensuring attachment. Subsequent improvements have reduced complication rates to levels experienced with DSEK. DMEK/DSEK hybrids and 'thin' DSEK also can provide better vision than standard DSEK; randomized controlled comparisons with DMEK are needed.
DMEK provides an anatomically exact replacement of dysfunctional host endothelium and has set new benchmarks for rejection risk and visual outcomes following endothelial replacement. DMEK is providing new insights into how different corneal layers contribute to immunogenicity and immune tolerance and into the key factors that limit vision after endothelial keratoplasty.
Descemet 膜内皮角膜移植术（DSEK）是治疗角膜内皮功能障碍的最常用方法，但现在 Descemet 膜内皮角膜移植术（DMEK）提供了更好的视力，免疫排斥的风险更低。尽管 DMEK 更具挑战性，但仪器和技术的进步正在缩短学习曲线。
与包括后供体基质的 DSEK 相反，DMEK 仅包含供体内皮细胞和 Descemet 膜，因此 DMEK 不会形成基质界面，并引起明显较少的后表面像差，从而获得更好的视力。此外，多个中心报告称，DMEK 术后 2 年内免疫移植物排斥事件的累积概率<1%，这一比例非常低。最初，最大的挑战是在准备和确保附着时组织丢失。随后的改进将并发症发生率降低到与 DSEK 相同的水平。DMEK/DSEK 杂交和“薄”DSEK 也可以提供比标准 DSEK 更好的视力；需要与 DMEK 进行随机对照比较。
DMEK 提供了功能失调的宿主内皮细胞的解剖学精确替代，为免疫排斥风险和内皮角膜移植术后的视觉结果设定了新的基准。DMEK 为不同的角膜层如何导致免疫原性和免疫耐受以及限制内皮角膜移植术后视力的关键因素提供了新的见解。
