Optometry Research Group, Universidade de Santiago de Compostela, A Coruña, Spain.
Eye Contact Lens. 2011 Mar;37(2):66-70. doi: 10.1097/ICL.0b013e31820c6ffc.
To evaluate the reliability of three noninvasive pachometry methods against the ultrasound pachometer considered the gold standard.
Central corneal thickness (CCT) was measured using a Paxis ultrasound (US) pachometer, Orbscan II, Pentacam, and Topcon SP-3000 specular microscope in 22 right eyes of 22 healthy adults (7 men, 15 women). Three repeated measures were obtained and then compared to obtain the repeatability of each instrument and the agreement between pachometers.
Pentacam is the optical system that renders values of CCT closer to those obtained with US pachometry. Conversely, a specular microscope shows a poorer agreement with US measures, and differences depend on the thickness being measured. The Orbscan system shows a consistent trend toward underestimation of CCT compared with US and Pentacam irrespective of the value measured.
Different optical methods used to measure CCT showed significantly different results compared with US pachometry except for the Pentacam system. Clinicians should take into account the fact that specular microscopy might either underestimate or overestimate values of CCT, whereas Orbscan systematically overestimates CCT compared with US and Pentacam.
评估三种非侵入性角膜测厚仪与超声角膜测厚仪（金标准）的可靠性。
在 22 名健康成年人（7 名男性，15 名女性）的 22 只右眼上，使用 Paxis 超声（US）角膜测厚仪、Orbscan II、Pentacam 和 Topcon SP-3000 共聚焦显微镜分别测量中央角膜厚度（CCT）。获得三次重复测量值，然后进行比较，以获得每种仪器的重复性和角膜测厚仪之间的一致性。
Pentacam 是一种光学系统，它提供的 CCT 值更接近 US 角膜测厚仪的测量值。相反，共聚焦显微镜与 US 测量值的一致性较差，差异取决于所测量的厚度。与 US 和 Pentacam 相比，Orbscan 系统无论测量值如何，都一致存在低估 CCT 的趋势。
与 US 角膜测厚仪相比，用于测量 CCT 的不同光学方法显示出明显不同的结果，除了 Pentacam 系统。临床医生应考虑到这样一个事实，即共聚焦显微镜可能会低估或高估 CCT 值，而 Orbscan 系统与 US 和 Pentacam 相比，会系统地高估 CCT 值。
