Department of Optics and Optometry and Vision Sciences, University of Valencia, C/Dr Moliner, 50, 46100, Burjassot, Spain.
Int Ophthalmol. 2021 Jul;41(7):2473-2483. doi: 10.1007/s10792-021-01802-4. Epub 2021 Mar 16.
The aim of this study is to assess the intraexaminer repeatability of Non-invasive Keratograph Break-Up Time (NIKBUT) obtained using the Oculus Keratograph 5M (K5M), given its relevance as a homeostasis marker in Dry Eye Disease (DED).
In total, 80 healthy volunteers aged between 30 and 89 years participated. Measurements were classified according to age, sex and the presence or not of DED. Repeatability was evaluated by the calculation of within-subject standard deviation (S), coefficient of repeatability (CoR) and coefficient of variation (CoV). Moreover, the Passing-Bablok regression method was applied.
S, CoR and CoV coefficients showed low repeatability in all groups with values between 3.57 and 7.14; 9.90 and 19.79; and 51.90 and 65.49, for each coefficient, respectively. No statistically significant differences were found in the NIKBUT measurements between healthy and DED patients (p = 0.188). Groups with more DED risk had better repeatability. Passing-Bablok regression also confirmed a lack of agreement between the maximum and minimum NIKBUT measurement.
NIKBUT measurement has low intraexaminer repeatability even when considering sex, age and DED diagnosis. Nevertheless, not only is this low repeatability due to the device, but also it is largely due to the intrinsic variability of the tear film.
本研究旨在评估使用 Oculus Keratograph 5M（K5M）获得的非侵入性角膜破裂时间（NIKBUT）的内部检查者重复性，因为它作为干眼症（DED）的内稳态标志物具有相关性。
共有 80 名年龄在 30 至 89 岁之间的健康志愿者参与。根据年龄、性别以及是否存在 DED，将测量值进行分类。通过计算个体内标准差（S）、可重复性系数（CoR）和变异系数（CoV）来评估重复性。此外，还应用了 Passing-Bablok 回归法。
S、CoR 和 CoV 系数在所有组中均表现出低重复性，其值分别在 3.57 至 7.14、9.90 至 19.79 和 51.90 至 65.49 之间。健康和 DED 患者之间的 NIKBUT 测量值没有统计学上的显著差异（p=0.188）。具有更高 DED 风险的组具有更好的重复性。Passing-Bablok 回归也证实了最大和最小 NIKBUT 测量值之间缺乏一致性。
即使考虑到性别、年龄和 DED 诊断，NIKBUT 测量也具有较低的内部检查者重复性。然而，这种低重复性不仅是由于设备引起的，而且在很大程度上是由于泪膜的固有可变性所致。
