Brockmann Tobias, Brockmann Claudia, Maier Anna-Karina, Schroeter Jan, Pleyer Uwe, Bertelmann Eckart, Joussen Antonia M, Torun Necip
Department of Ophthalmology, Charité - University Medicine Berlin, Berlin, Germany.
Acta Ophthalmol. 2014 Nov;92(7):e556-61. doi: 10.1111/aos.12419. Epub 2014 Apr 13.
To investigate pathomechanisms involved in graft detachment after Descemet's membrane endothelial keratoplasty (DMEK) and its clinical implications.
In a prospective case series, 30 eyes with Fuchs' endothelial dystrophy underwent DMEK. Intraoperatively obtained recipients' endothelium-Descemet's membranes (EDMs) were investigated histologically and immunohistochemically. The postoperative donor graft status was categorized as attached or detached. Clinical and morphological parameters were analysed between the study groups.
The detachment rate was 40% (12/30). There was no significant difference in postoperative visual acuity between the groups, but visual recovery was delayed in eyes with initially detached grafts. Gender, age, preoperative central corneal thickness or best corrected visual acuity did not influence the detachment rate. However, separation and disruption of the anterior banded layer (ABL) were frequently observed in patients with graft detachment, and ABL thickness was identified as a significant predictor for graft detachment. The ABL thickness was 2.5 ± 0.9 μm and 3.5 ± 1.6 μm in patients with attached and detached grafts, respectively. Immunohistologically, a deficiency of fibronectin and cytokeratin was observed within the ABL of patients with detached grafts. In contrast, a complete removal of the EDM with residual stromal collagen fragments was observed in patients with adherent grafts.
Incomplete removal of the EDM, with residual ABL fragments on the recipients' corneal stroma, may be a risk factor for graft detachment after DMEK. The separation and disruption of the ABL might be promoted by a deficiency of matrix proteins, stronger biomechanical properties and a firm adherence to the posterior corneal stroma.
探讨Descemet膜内皮角膜移植术（DMEK）后植片脱离的发病机制及其临床意义。
在一项前瞻性病例系列研究中，30例患有Fuchs内皮营养不良的患者接受了DMEK手术。对术中获取的受体角膜内皮-Descemet膜（EDM）进行组织学和免疫组织化学研究。术后将供体植片状态分为附着或脱离。对研究组之间的临床和形态学参数进行分析。
脱离率为40%（12/30）。两组术后视力无显著差异，但最初植片脱离的患者视力恢复延迟。性别、年龄、术前中央角膜厚度或最佳矫正视力均不影响脱离率。然而，在植片脱离的患者中经常观察到前弹力层（ABL）的分离和破坏，并且ABL厚度被确定为植片脱离的一个重要预测因素。附着和脱离植片的患者ABL厚度分别为2.5±0.9μm和3.5±1.6μm。免疫组织化学研究显示，脱离植片患者的ABL内观察到纤连蛋白和细胞角蛋白缺乏。相比之下，附着植片的患者观察到EDM完全去除，伴有残留的基质胶原片段。
受体角膜基质上残留ABL片段，EDM未完全去除，可能是DMEK术后植片脱离的一个危险因素。基质蛋白缺乏、更强的生物力学特性以及与后角膜基质的牢固附着可能会促进ABL的分离和破坏。
