Optimal Image Sample Size for Corneal Nerve Morphometry
Optimal Image Sample Size for Corneal Nerve Morphometry
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DOI：
10.1097/opx.0b013e31824ee8c9
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发表时间：
2012-05-01
影响因子：
1.4
通讯作者：
Efron, Nathan
中科院分区：
文献类型：
--
作者：
Vagenas, Dimitrios;Pritchard, Nicola;Efron, Nathan
目的。任意数量的角膜共聚焦显微镜图像被用于分析角膜基底下神经参数，隐含的假设是这些是角膜中枢神经丛的代表性样本。本研究的目的是提出一种量化随机角膜中央图像数量的技术，以达到测量角膜神经纤维长度和分支密度的可接受精度水平。我们对20名患有不同程度功能性神经缺损的2型糖尿病患者的神经纤维长度和分支密度进行了评估，每组2 - 16张角膜中央基底下神经丛的图像（其中16张被认为是真实平均值）重叠不超过20%。计算平均比率，以便在受试者之间和受试者内部进行比较。在评估神经分支密度时，随机选择8张重叠不超过20%的图像，在95%的情况下产生的平均值与真实平均值的误差在30%以内。类似的五张图像的采样策略在角膜神经纤维长度的真实平均80%的时间内占13%。这里提出的“样本组合分析”可用于确定定量角膜基底下神经参数的准确度所需的样本量。该技术在其他生物取样研究中也有应用前景。（光学视觉科学2012；89:812-817）
Purpose. Arbitrary numbers of corneal confocal microscopy images have been used for analysis of corneal subbasal nerve parameters under the implicit assumption that these are a representative sample of the central corneal nerve plexus. The purpose of this study is to present a technique for quantifying the number of random central corneal images required to achieve an acceptable level of accuracy in the measurement of corneal nerve fiber length and branch density.Methods. Every possible combination of 2 to 16 images (where 16 was deemed the true mean) of the central corneal subbasal nerve plexus, not overlapping by more than 20%, were assessed for nerve fiber length and branch density in 20 subjects with type 2 diabetes and varying degrees of functional nerve deficit. Mean ratios were calculated to allow comparisons between and within subjects.Results. In assessing nerve branch density, eight randomly chosen images not overlapping by more than 20% produced an average that was within 30% of the true mean 95% of the time. A similar sampling strategy of five images was 13% within the true mean 80% of the time for corneal nerve fiber length.Conclusions. The "sample combination analysis" presented here can be used to determine the sample size required for a desired level of accuracy of quantification of corneal subbasal nerve parameters. This technique may have applications in other biological sampling studies. (Optom Vis Sci 2012;89:812-817)