Zhang Huina, Zhou Hongjie, Zhu Tiepei, Ye Juan
Department of Ophthalmology, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
Hangzhou Hospital for the Prevention and Treatment of Occupational Diseases, Hangzhou, Zhejiang, China.
BMC Ophthalmol. 2018 Sep 5;18(1):239. doi: 10.1186/s12886-018-0897-9.
To investigate changes in corneal elevation, pachymetry, and keratometry in discriminating between normal and blepharospasm eyes, as measured by the Pentacam rotating Scheimpflug camera.
This was a prospective, cross-sectional study. A total of 47 consecutive patients with a range of blepharospasm severity and 40 age- and sex- matched healthy subjects were included, one eye of each subject was randomly chosen for data analysis. Blepharospasm severity was evaluated using the Jankovic scale and categorized as mild, moderate, or severe. Corneal parameters were measured by the Pentacam rotating Scheimpflug camera to derive corneal tomography information. Various parameters regarding keratometry, elevation at the anterior and posterior corneal surface, pachymetric data, final D value, and topometric indices from the Pentacam software were recorded, and the relationship between the blink rate and corneal parameters was analyzed. Intraclass correlation coefficients (ICCs) were assessed to evaluate the repeatability of intraobserver.
Increased topographic asymmetry was observed in moderate and severe blepharospasm. Front K1and front Km were significantly higher in cases of mild (P < 0.05), moderate (P < 0.0001), and severe (P < 0.0001) blepharospasm as compared with controls. Front K2, back K1, back K2, and back Km were significantly higher in cases of moderate (P < 0.01) and severe (P < 0.001) blepharospasm as compared with controls. For corneal topometric indices, both ISV and IVA were significantly increased in severe blepharospasm (P < 0.05). Radii minimum were significantly increased in cases of moderate and severe blepharospasm (P < 0.05).There were no differences in corneal elevation and corneal pharcymetric parameters among the four groups, except for front BFS, which was significantly different in blepharospasm groups (P < 0.05). Final D values were significantly higher in the severe blepharospasm (P < 0.01) group than that among controls. There were significant correlations between the blink rate and most corneal tomographic parameters. All parameters showed high reproducibility (ICC: 0.921-0.996) for normal and blepharospasm subjects.
Blepharospasm may lead to a redistribution of the pressure applied by the lids over the cornea and, consequently, may result in corneal shape changes, which can be documented through corneal topography.
通过Pentacam旋转式Scheimpflug相机测量，研究角膜高度、角膜厚度测量和角膜曲率测量在鉴别正常眼和眼睑痉挛眼中的变化。
这是一项前瞻性横断面研究。纳入了47例连续的不同程度眼睑痉挛患者以及40名年龄和性别匹配的健康受试者，每个受试者随机选择一只眼睛进行数据分析。使用扬科维奇量表评估眼睑痉挛的严重程度，并分为轻度、中度或重度。通过Pentacam旋转式Scheimpflug相机测量角膜参数以获取角膜断层扫描信息。记录来自Pentacam软件的关于角膜曲率测量、角膜前表面和后表面高度、角膜厚度数据、最终D值和地形测量指数的各种参数，并分析眨眼频率与角膜参数之间的关系。评估组内相关系数（ICC）以评估观察者内的重复性。
在中度和重度眼睑痉挛中观察到地形不对称增加。与对照组相比，轻度（P < 0.05）、中度（P < 0.0001）和重度（P < 0.0001）眼睑痉挛患者的前表面K1和前表面Km显著更高。与对照组相比，中度（P < 0.01）和重度（P < 0.001）眼睑痉挛患者的前表面K2、后表面K1、后表面K2和后表面Km显著更高。对于角膜地形测量指数，在重度眼睑痉挛中ISV和IVA均显著增加（P < 0.05）。在中度和重度眼睑痉挛中最小半径显著增加（P < 0.05）。除了前表面BFS在眼睑痉挛组中有显著差异（P < 0.05）外，四组之间的角膜高度和角膜厚度测量参数没有差异。重度眼睑痉挛组的最终D值显著高于对照组（P < 0.01）。眨眼频率与大多数角膜断层扫描参数之间存在显著相关性。所有参数在正常和眼睑痉挛受试者中均显示出高重复性（ICC：0.921 - 0.996）。
眼睑痉挛可能导致眼睑施加在角膜上的压力重新分布，因此可能导致角膜形状改变，这可以通过角膜地形图记录下来。
