Department of Ophthalmology, Medical Faculty Carl Gustav Carus, Technische Universität, Fetscherstrasse, Dresden, Germany.
J Glaucoma. 2019 Jun;28(6):540-545. doi: 10.1097/IJG.0000000000001231.
PRéCIS:: Optical and ultrasound pachymetry cannot be used interchangeably in young, healthy adults. In elderly, healthy and glaucoma patients the speed of ultrasound in the cornea increases because of changing corneal biomechanical characteristics in age and disease and the different devices could be used interchangeably.
The purpose of this study was to compare central corneal thickness (CCT) using optical and ultrasound pachymetry in patients with open-angle glaucoma and young as well as elderly, healthy controls. Further to investigate whether the devices could be used interchangeably.
In total, 69 eyes of 41 glaucoma patients, 51 eyes of 32 elderly and 50 eyes of 25 young controls were consecutively included in this cross-sectional observational study. Optical CCT measurements were obtained using the noncontact Specular Microscope CEM-530 (NCSM). Ultrasound pachymetry (USP) was measured using the Pachy Meter SP 3000.
In young subjects (27.2±4.8 y), the mean CCT taken with NCSM and USP was 562.1±33.6 μm and 565.8±35.8 μm, respectively. This was significantly different (USP>NCSM, P=0.019). In elderly subjects (70.6±10.7 y) CCT measured with NCSM (562.5±27.8 μm) compared to USP (564.9±27.1 μm) was not statistically significantly different (P= 0.121). In glaucoma patients (65.0±11.1 y), USP measured thinner CCT values compared to NCSM, without significant differences between the devices (NCSM 525.3±32.3 μm; USP 522.9±33.15 μm; P=0.067). CCT was significantly thinner in comparison to both healthy groups (P< 0.001).
In young subjects, ultrasound pachymetry measurements are higher than they are with optical pachymetry. This difference is no longer observed in elderly subjects and is even reversed in glaucoma patients. A higher speed of ultrasound in the cornea due to changing corneal biomechanical properties in the elderly and glaucoma patients could explain this. The devices could be used interchangeably in older and glaucoma patients, but not in young individuals.
摘要：光学和超声角膜测厚仪不能在年轻健康成年人中互换使用。在老年、健康和青光眼患者中，由于角膜生物力学特性随年龄和疾病的变化，以及不同的设备可以互换使用，因此角膜的超声速度会增加。目的：本研究的目的是比较光学和超声角膜测厚仪在开角型青光眼患者以及年轻和老年健康对照组中的中央角膜厚度（CCT）。进一步研究设备是否可以互换使用。方法：本横断面观察性研究共纳入 41 例青光眼患者的 69 只眼、32 例老年患者的 51 只眼和 25 例年轻患者的 50 只眼。使用非接触式共焦显微镜 CEM-530（NCSM）进行光学 CCT 测量。使用 Pachy Meter SP 3000 进行超声角膜测厚（USP）。结果：在年轻受试者（27.2±4.8 岁）中，NCSM 和 USP 测量的平均 CCT 分别为 562.1±33.6μm 和 565.8±35.8μm，两者差异具有统计学意义（USP>NCSM，P=0.019）。在老年受试者（70.6±10.7 岁）中，NCSM 测量的 CCT（562.5±27.8μm）与 USP（564.9±27.1μm）相比无统计学差异（P=0.121）。在青光眼患者（65.0±11.1 岁）中，USP 测量的 CCT 值比 NCSM 薄，但两种设备之间无显著差异（NCSM 525.3±32.3μm；USP 522.9±33.15μm；P=0.067）。与两个健康组相比，CCT 值明显变薄（P<0.001）。结论：在年轻受试者中，超声角膜测厚仪的测量值高于光学角膜测厚仪。在老年受试者中，这种差异不再存在，甚至在青光眼患者中出现逆转。这可能是由于老年和青光眼患者角膜生物力学特性的变化导致角膜内超声速度加快所致。对于老年和青光眼患者，这些设备可以互换使用，但对于年轻个体则不行。
