International Vision Correction Research Centre (IVCRC), Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany.
Eye (Lond). 2024 Oct;38(15):2968-2975. doi: 10.1038/s41433-024-03199-7. Epub 2024 Jul 13.
To develop and test a parameter for early keratoconus screening by quantifying the localized epithelial thickness differences in keratoconic eyes.
The cross-sectional study included 189 eyes of 116 subjects in total: 86 eyes of 54 keratoconus patients with bilateral ectasia and 40 eyes of 20 healthy subjects in the parameter-development dataset and 42 eyes of 21 keratoconus patients with asymmetric ectasia and 21 eyes of 21 healthy subjects in the parameter-validation dataset. Epithelial thickness maps were obtained using anterior segment optical coherence tomography and the inter-zonal epithelial thickness differences were calculated. The developed parameter was tested in keratoconus patients with asymmetric ectasia.
Compared to healthy controls, the inferior-temporal and global inter-zonal epithelial thickness differences were higher not only in eyes with tomographically significant keratoconus (median [interquartile range] of 4.42 [3.13] µm vs. 0.78 [0.42] µm, p < 0.001, and 3.05 [1.51] µm vs. 1.07 [0.26] µm, p < 0.001, respectively), but also in tomographically normal keratoconus fellow eyes (1.36 [0.85] µm vs. 0.78 [0.42] µm, p = 0.005, and 1.31 [0.32] µm vs. 1.07 [0.26] µm, p = 0.01, respectively). The inferior-temporal inter-zonal epithelial thickness differences had an area under the receiver operating characteristic curve (95% confidence interval) of 0.991 (0.972-1) for detecting tomographically significant keratoconus and 0.749 (0.598-0.901) for differentiating between tomographically normal keratoconus fellow eyes and healthy controls.
The inter-zonal epithelial thickness differences are increased in keratoconus fellow eyes which still have a normal Scheimpflug corneal tomography, and therefore may serve as a useful parameter to detect early ectatic changes.
通过量化圆锥角膜眼中局部上皮厚度差异，开发并测试一种用于早期圆锥角膜筛查的参数。
这项横断面研究共纳入 116 名受试者的 189 只眼：参数开发数据集包括 54 名双侧扩张性圆锥角膜患者的 86 只眼和 20 名健康受试者的 40 只眼，参数验证数据集包括 21 名单侧扩张性圆锥角膜患者的 42 只眼和 21 名健康受试者的 21 只眼。使用眼前节光学相干断层扫描获得上皮厚度图，并计算各区域间上皮厚度差异。在单侧扩张性圆锥角膜患者中对开发的参数进行测试。
与健康对照组相比，不仅在具有明显角膜地形图特征的圆锥角膜眼中（中位数[四分位距]分别为 4.42[3.13]μm 和 0.78[0.42]μm，p<0.001，以及 3.05[1.51]μm 和 1.07[0.26]μm，p<0.001），而且在具有正常角膜地形图的圆锥角膜对侧眼中（中位数[四分位距]分别为 1.36[0.85]μm 和 0.78[0.42]μm，p=0.005，以及 1.31[0.32]μm 和 1.07[0.26]μm，p=0.01），下颞部和全眼球各区域间上皮厚度差异均更高。下颞部各区域间上皮厚度差异的受试者工作特征曲线下面积（95%置信区间）为 0.991（0.972-1），用于检测具有明显角膜地形图特征的圆锥角膜，为 0.749（0.598-0.901），用于区分具有正常角膜地形图的圆锥角膜对侧眼和健康对照组。
即使圆锥角膜对侧眼的角膜地形图仍正常，各区域间上皮厚度差异也会增加，因此可能是一种有用的参数，可用于检测早期扩张性改变。
