Faculty of Medicine, University of Manitoba, Winnipeg, Man., Canada.
Can J Ophthalmol. 2009 Dec;44(6):700-4. doi: 10.3129/i09-172.
To evaluate the interchangeability of a Scheimpflug camera (Pentacam, Oculus) and a partial coherence interferometry keratometer (IOLMaster, Zeiss) for measures of keratometry and anterior chamber depth (ACD). A particular focus was to determine which Pentacam keratometry value best correlates with the IOLMaster and if these results can be used interchangeably in clinical practice.
Retrospective comparative study using data from the GRMC Vision Centre and ImagePlus Laser Eye Centre.
Fifty-two eyes from 27 patients (11 male, 16 female) of normal general health with no history of ocular disease.
Each eye was assessed by an IOLMaster as part of a complete eye examination, and later by the Pentacam, prior to laser in situ keratomileusis (LASIK) surgery.
The differences in the mean keratometry readings of the IOLMaster and those of the simulated and equivalent Pentacam measurements were 0.35 D and 0.23 D, respectively. The Bland-Altman plots showed 95% limits of agreement (LOA) of 0.92 D and 1.68 D for the same parameters. A comparison of ACD measurements revealed a 0.03 mm difference in mean measurements with a 95% LOA of 0.33 mm.
The interdevice variability was significantly lower than that reported previously but still warrants caution if the 2 instruments are to be used interchangeably. With an appropriate correction for mean differences, the Pentacam's simulated keratometry values would be within 0.46 D of the IOLMaster, 95% of the time. When the Holladay equivalent keratometry values were compared with the IOLMaster, a greater interdevice variability was seen.
评估 Scheimpflug 相机（Pentacam，Oculus）和部分相干干涉角膜曲率计（IOLMaster，蔡司）在角膜曲率和前房深度（ACD）测量方面的互换性。特别关注的是确定哪个 Pentacam 角膜曲率值与 IOLMaster 相关性最佳，以及这些结果是否可以在临床实践中互换使用。
使用来自 GRMC 视觉中心和 ImagePlus 激光眼科中心的数据进行回顾性比较研究。
27 名正常健康患者（11 名男性，16 名女性）的 52 只眼睛，无眼部疾病史。
每只眼睛在 LASIK 手术前，作为全面眼科检查的一部分，由 IOLMaster 进行评估，然后由 Pentacam 进行评估。
IOLMaster 的平均角膜曲率读数与模拟和等效 Pentacam 测量值的差异分别为 0.35 D 和 0.23 D。Bland-Altman 图显示相同参数的 95%一致性界限（LOA）为 0.92 D 和 1.68 D。ACD 测量值的比较显示平均测量值相差 0.03 mm，95% LOA 为 0.33 mm。
设备间的可变性虽然明显低于先前报道的水平，但如果要互换使用这两种仪器，仍需谨慎。通过对平均差异进行适当校正，Pentacam 的模拟角膜曲率值将有 95%的时间在 0.46 D 以内与 IOLMaster 一致。当比较 Holladay 等效角膜曲率值与 IOLMaster 时，发现设备间的可变性更大。
