From the Department of Ophthalmology (McAlinden), Singleton Hospital, Swansea Bay University Health Board, Swansea, United Kingdom; College of Optical Sciences (Schwiegerling), University of Arizona, and Department of Ophthalmology & Vision Sciences (Schwiegerling), University of Arizona, Tucson, Arizona, USA; Institute for Choice (Khadka), UniSA Business School, University of South Australia, Healthy Aging Consortium (Khadka), South Australian Health and Medical Research Institute, Adelaide, and Australian College of Optometry (Pesudovs), Carlton, Victoria, SA2 8QA Australia.
J Cataract Refract Surg. 2020 Apr;46(4):581-590. doi: 10.1097/j.jcrs.0000000000000084.
To evaluate the precision of elevation and wavefront aberration measurements with the Pentacam HR (Oculus Optikgeräte GmbH).
Flinders University, Australia.
Instrument evaluation study.
A randomly selected eye of 100 participants was scanned twice with the Pentacam HR by 1 observer on the 3 measurement modes: 25-picture, 50-picture, and cornea fine. A second observer performed 2 scans on the same random eye with the 25-picture mode. Repeatability and reproducibility were assessed using the within-subject SD (Sw) statistic from a 1-way analysis of variance.
From the 100 scanned eyes, the higher-order aberration root mean square (RMS) repeatability limit for both elevation and wavefront, and anterior and posterior measurements was 0.03 μm for all 3 measurement modes. Anterior, posterior, and total corneal wavefront Zernike terms were highly precise, with most Zernike terms displaying a repeatability limit of 0.03 μm. The least repeatable measurement was the posterior elevation Zernike term with the 25-picture scan (repeatability limit 1.50 μm). The cornea fine measurement mode provided the most precise measurements. Reproducibility limits (second observer) were similar to repeatability limits with the 25-picture scan mode.
The Pentacam HR provided highly precise aberration outputs. The most precise measurements are achievable with the cornea fine measurement mode and wavefront aberrations. One should be cognizant of posterior elevation aberration precision, particularly for lower radial order and higher azimuthal frequency terms. Accounting for tilt and misalignment of aberrations, all RMS and Zernike aberrations were extremely precise (repeatability and reproducibility limit less than 0.000001 μm).
评估 Pentacam HR（Oculus Optikgeräte GmbH）测量高度和波前像差的精度。
澳大利亚弗林德斯大学。
仪器评估研究。
由一位观察者在 3 种测量模式（25 幅图、50 幅图和角膜精细）下对 100 名参与者的随机一只眼进行两次扫描。第二位观察者对同一随机眼进行两次 25 幅图模式扫描。使用单因素方差分析的组内标准差（Sw）统计量评估重复性和再现性。
在 100 只扫描眼中，所有 3 种测量模式的高度和波前、前表面和后表面的高阶像差均方根（RMS）重复性极限均为 0.03μm。前表面、后表面和总角膜波前泽尼克项高度精确，大多数泽尼克项的重复性极限为 0.03μm。25 幅图扫描的后表面高度泽尼克项的重复性最差（重复性极限 1.50μm）。角膜精细测量模式提供最精确的测量值。再现性极限（第二位观察者）与 25 幅图扫描模式的重复性极限相似。
Pentacam HR 提供了高度精确的像差输出。角膜精细测量模式和波前像差可实现最精确的测量。应注意后表面高度像差的精度，特别是对于较低的径向阶数和较高的方位频率项。考虑到像差的倾斜和不对准，所有 RMS 和泽尼克像差都非常精确（重复性和再现性极限小于 0.000001μm）。
