Klijn Stijn, Reus Nicolaas J, Sicam Victor Arni D P
J Refract Surg. 2015 Apr;31(4):249-56. doi: 10.3928/1081597X-20150212-01.
To assess the performance of a novel keratometer based on reflections of colored light-emitting diodes (LEDs) and compare it with devices based on Placido rings, monochromatic LEDs, and Scheimpflug images.
Sixty-three eyes of 63 patients with virgin corneas underwent keratometry with color-LED corneal topography (Cassini; i-Optics, The Hague, The Netherlands) and with devices based on Placido ring reflections (Keratron; Optikon, Rome, Italy), monochromatic LED reflections (Lenstar; Haag-Streit, Koeniz, Switzerland), and Scheimpflug imaging (Pentacam; Oculus Optikgeräte, Wetzlar, Germany). Three repeated measurements were performed with each device. Comparability and repeatability of corneal power and cylinder measurements were assessed. The Bonferroni-corrected α-threshold for statistical significance was 0.016.
Corneal power measurements with the Cassini topographer were not statistically significantly different from those with the Pentacam (P = .64). They were statistically significantly lower than those with the Keratron and Lenstar (P < .01), but the differences were of negligible clinical relevance. Cylinder measurements with the Cassini topographer were not statistically significantly different from those with any other device (P = .46). Repeatability of Cassini corneal power measurements was not statistically significantly different from that of the Keratron (P = .02), but was statistically significantly lower than that of the Lenstar and Pentacam (P < .001). Repeatability of Cassini cylinder measurements was statistically significantly higher than that of the Pentacam and Keratron (P < .001), but was not statistically significantly different from that of the Lenstar (P > .05).
Corneal power and cylinder measurements with color-LED corneal topography yielded values that were comparable to those of other commonly used devices. Repeatability of corneal power measurements was lower compared to some devices, but repeatability of cylinder measurements was relatively high. This may be of particular interest when using toric intraocular lenses.
评估一种基于彩色发光二极管（LED）反射的新型角膜曲率计的性能，并将其与基于普拉西多环、单色LED和Scheimpflug图像的设备进行比较。
对63例初次角膜患者的63只眼进行角膜曲率测量，使用彩色LED角膜地形图仪（Cassini；i-Optics，荷兰海牙）以及基于普拉西多环反射的设备（Keratron；Optikon，意大利罗马）、单色LED反射设备（Lenstar；Haag-Streit，瑞士柯尼茨）和Scheimpflug成像设备（Pentacam；Oculus Optikgeräte，德国韦茨拉尔）。每种设备均进行三次重复测量。评估角膜屈光力和柱镜测量值的可比性和可重复性。经Bonferroni校正的具有统计学意义的α阈值为0.016。
Cassini地形图仪测量的角膜屈光力与Pentacam测量的结果在统计学上无显著差异（P = 0.64）。其结果在统计学上显著低于Keratron和Lenstar测量的结果（P < 0.01），但这些差异的临床相关性可忽略不计。Cassini地形图仪测量的柱镜值与其他任何设备测量的结果在统计学上无显著差异（P = 0.46）。Cassini角膜屈光力测量的可重复性与Keratron的可重复性在统计学上无显著差异（P = 0.02），但显著低于Lenstar和Pentacam的可重复性（P < 0.001）。Cassini柱镜测量的可重复性显著高于Pentacam和Keratron的可重复性（P < 0.001），但与Lenstar的可重复性在统计学上无显著差异（P > 0.05）。
彩色LED角膜地形图测量的角膜屈光力和柱镜值与其他常用设备测量的值具有可比性。角膜屈光力测量的可重复性与某些设备相比更低，但柱镜测量的可重复性相对较高。在使用散光人工晶状体时，这可能具有特别的意义。
