Department of Ophthalmology, University Medicine Rostock, Rostock, Germany.
Institute of Medical Biochemistry and Molecular Biology, University Medicine Rostock, Rostock, Germany.
Invest Ophthalmol Vis Sci. 2020 Dec 1;61(14):1. doi: 10.1167/iovs.61.14.1.
To elucidate the collagen structure in the Descemet membrane (DM) of the human cornea and to characterize its rearrangement in patients with endothelial corneal dystrophies.
Corneas from nine human donors and dystrophic DMs removed from 16 affected eyes of 13 patients by endothelial keratoplasty (DMEK) were investigated using a correlative RT-qPCR and label-free two-channel multiphoton microscopy (MPM) setup. Although collagen formation was visualized by second harmonic generation, the cellular structure was determined by autofluorescence.
The DM of the human donor cornea was characterized by a consistent pattern of fine hexagonal collagen structures that form a supportive scaffold for the endothelial cells. Accordingly, network-forming collagens (8A1 and 8A2) but less fibrillar collagens (only 1A2) were expressed. DMEK resulted in significant (P < 0.0001) improvement of best-corrected visual acuity. In the removed dystrophic DMs, MPM analyses revealed collagen rearrangement in addition to loss of endothelial cells and the development of guttae. MPM analyses of the whole patient's DM demonstrated this collagen remodeling in its entirety and facilitated correlation to Scheimpflug corneal tomography. In most DMs a unique honeycomb collagen network was identified, with distinct bundles surrounding the guttae and correlating with expression of fibrillar collagens (1A1). Conversely, some DMs showed either reduced collagen on MPM and RT-qPCR analysis or diffuse thickening and storage of extracellular matrix.
The collagen structure of the DM and its adaptive remodeling in endothelial corneal dystrophies has been characterized for the first time here and will facilitate individual therapeutic approaches.
阐明人眼角膜内皮层（Descemet 膜，DM）中的胶原结构，并对其在角膜内皮营养不良患者中的重排进行特征描述。
采用相关的 RT-qPCR 和无标记双通道多光子显微镜（MPM）设置，研究了 9 位人类供体角膜和 13 位患者通过内皮角膜移植术（DMEK）去除的 16 只病变眼的病变 DM。虽然通过二次谐波产生观察到胶原形成，但细胞结构是通过自发荧光确定的。
人供体角膜的 DM 表现为一致的精细六边形胶原结构模式，为内皮细胞形成支持性支架。因此，表达了网络形成胶原（8A1 和 8A2），而较少表达纤维状胶原（仅 1A2）。DMEK 导致最佳矫正视力显著（P < 0.0001）改善。在去除的病变 DM 中，MPM 分析除了内皮细胞丢失和出现胶滴外，还揭示了胶原重排。对整个患者 DM 的 MPM 分析全面揭示了这种胶原重塑，并促进了与 Scheimpflug 角膜断层扫描的相关性。在大多数 DM 中，鉴定到独特的蜂窝状胶原网络，其特征是围绕胶滴的明显束，与纤维状胶原（1A1）的表达相关。相反，一些 DM 显示 MPM 和 RT-qPCR 分析中的胶原减少，或弥漫性增厚和细胞外基质的储存。
首次对 DM 的胶原结构及其在角膜内皮营养不良中的适应性重塑进行了特征描述，这将有助于个体化的治疗方法。
