3D-CCM – Three-dimensional in vivo microscopy of the cornea for the diagnosis of Ocular Surface Diseases

角膜、结膜、角膜缘之间的功能关系以及它们与泪膜和眼睑器官的相互连接维持着角膜表面--尤其是角膜上皮--的完整性。由这种平衡失调引起的疾病统称为眼表疾病(OSD)。OSD可由泪液分泌障碍、感染性或非感染性炎症或热/化学创伤后的瘢痕形成引起，也可由糖尿病、角膜缘干细胞缺陷或眉腺功能障碍引起。OSD的诊断在制定针对病因和患者的治疗策略中起着至关重要的作用。目前建立的方法允许对角膜变化进行宏观描述，但由于分辨率不够高，无法在细胞水平上进行定量表征。唯一提供非侵入性接触这些细胞区域的方法是活体角膜共焦显微镜(CCM)。然而，细胞变化的量化目前仅限于小视场的2D分析，几乎不是特定位置的，并且通常需要大量的人工后处理。此外，表面平行成像与眼科医生日常使用的裂隙灯检查的轴向图像不对应。由于这些限制，CCM很少在临床常规中应用。拟议的项目解决了这些方法上的缺陷，并开发了高分辨率、广域3D成像技术和方法，用于上皮细胞结构的体积形态计量表征。自动化3D成像技术确保可靠地采集扩展体积，同时最大限度地缩短采集持续时间。在任意图像平面上的在线可视化将使眼科医生能够实时定性地评估角膜组织或角膜缺损的尺寸。在成像过程之后，将从2D图像数据集中重建整个记录组织区域的高精度体积表示，为可靠的角膜组织形态计量分析提供基础。根据重建的体积，将计算具有3D位置信息的上皮组织和相邻的基底下神经丛的体积特征。拟议的项目建立在DFG项目Biomarker的基础上，并为在细胞水平上的角膜组织的体积特征提供了一种新的方法，可以提高临床诊断水平，并进一步开发针对原因和患者的OSD治疗策略。新的三维成像技术和任意方向像面的可视化将为高分辨率定量裂隙灯显微镜奠定基础。

The integrity of the corneal surface – particularly the epithelium – is maintained by the functional relations between cornea, conjunctiva, limbus, and their interconnections with the tear film and lid apparatus. Disorders arising from disturbances of this balance are collectively termed Ocular Surface Diseases (OSD). OSD may be caused by tear secretion malfunctions, scar formation following infectious or non-infectious inflammation or thermal/chemical trauma, but also by diabetes mellitus, limbal stem cell deficiencies or Meibomian gland dysfunction.Diagnosis of OSD plays an essential role in the development of cause- and patient-specific treatment strategies. Currently established methods allow for the macroscopic description of corneal alterations, but not for quantitative characterization on a cellular level due to insufficient resolution. The only available method that provides non-invasive access to these cellular areas is in vivo corneal confocal microscopy (CCM). However, quantification of cellular alterations is currently restricted to 2D analyses with small fields of view, hardly location-specific, and often requires extensive manual postprocessing. Furthermore, the surface-parallel image formation does not correspond to the axial images of slit lamp examinations that ophthalmologists use on a daily basis. With these constraints, CCM is rarely implemented in clinical routines.The proposed project addresses these methodical deficits and develops high resolution, wide-field 3D imaging technologies and methods for the volumetric morphometric characterization of epithelial cell structures. Automated 3D imaging techniques ensure the reliable acquisition of an extended volume while simultaneously minimizing acquisition duration. Online visualization in arbitrary image planes will enable the ophthalmologist to qualitatively assess the corneal tissue or the dimension of corneal defects in real-time. Following the imaging process, a high-precision volume representation of the entire recorded tissue region will be reconstructed from the 2D image datasets, providing the basis for a reliable morphometric analysis of the corneal tissue. From the reconstructed volumes, volumetric features with 3D location information will be calculated for the epithelial tissue and the adjacent subbasal nerve plexus.The proposed project builds on the DFG project Biomarker and offers a novel approach for a volumetric characterization of the corneal tissue on a cellular level that can advance clinical diagnostics and further the development of cause- and patient-specific treatment strategies for OSD. The novel 3D imaging techniques and visualization of arbitrarily oriented image planes will lay the foundations for high-resolution quantitative slit lamp microscopy.