Semiquantitative optic nerve grading scheme for determining axonal loss in experimental optic neuropathy
Semiquantitative optic nerve grading scheme for determining axonal loss in experimental optic neuropathy
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DOI：
10.1167/iovs.05-1206
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发表时间：
2006-02-01
影响因子：
4.4
通讯作者：
Archibald, ML
中科院分区：
文献类型：
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作者：
Chauhan, BC;LeVatte, TL;Archibald, ML
目的.描述和评价一种半定量视神经分级方案，用于评估内皮素（ET）-1诱导的慢性视神经病变的轴突损失。视神经横截面从39布朗挪威大鼠的双眼单方面治疗不同浓度的ET-1或生理盐水溶液通过手术植入的渗透微型泵进行处理的光和透射电子显微镜（TEM）。视神经损伤等级介于0（无损伤）和10（总损伤）之间，基于大致相等损伤的区域数量和每个区域内损伤的平均百分比。由三名观察员在光学显微镜下进行分级，并与使用两种定量方法用TEM确定的轴突存活进行比较：取样方法，其中对近似10%的切片进行计数，以及全计数方法，其中对整个切片进行计数（n = 12）。轴突存活率表示为实验眼与对照眼的轴突计数比率。在进行这些比较之前，分别测定了另一组85只和12只ET-1治疗动物的观察者间和观察者内一致率。结果。所有眼睛的观察者间kappa为0.66（95%置信区间[CI]：0.58-0.74），仅实验眼睛为0.55（95% CI：0.43-0.67）。所有24只眼的观察者内kappa分别为0.80、0.81和0.80，仅实验眼为0.60、0.64和0.71。使用TEM取样方法的实验眼损伤等级与轴突存活之间的相关性（对于所有动物，斯皮尔曼的p = -0.677，对于仅具有全计数的动物子集，为-0.827）低于使用全计数方法的相关性（斯皮尔曼的p = -0.926）。当轴突存活率小于0.7时，取样方法往往低估了损伤的程度。该分级方案具有良好的观察者间和观察者内一致性，并且与TEM方法高度相关。这是一种实用且节省时间的方法，每个神经需要不到1分钟，并且是可能产生重大错误的采样方法的替代方法。
PURPOSE. To describe and evaluate a semiquantitative optic nerve grading scheme for assessing axonal loss in endothelin (ET)-1-induced chronic optic neuropathy.METHODS. Optic nerve cross-sections from both eyes of 39 Brown Norway rats unilaterally treated with various concentrations of ET-1 or physiological saline solution via a surgically implanted osmotic minipump were processed for light and transmission electron microscopy (TEM). The optic nerve damage grade, between 0 (no damage) and 10 (total damage), was based on the number of zones of approximately equal damage and the mean percentage of damage within each zone. Grading was performed under light microscopy by three observers and compared with axonal survival determined with TEM using two quantification methods: the sampling method, in which similar to 10% of the section was counted, and the full-count method, in which the whole section was counted (n = 12). Axonal survival was expressed as a ratio of axon counts in the experimental to control eye. Before these comparisons, the inter-and intraobserver agreement rates were determined in another group of 85 and 12 ET-1-treated animals, respectively.RESULTS. The interobserver kappa was 0.66 (95% confidence interval [CI]: 0.58-0.74) for all eyes and 0.55 (95% CI: 0.43-0.67) for the experimental eyes only. The intraobserver kappa was 0.80, 0.81, and 0.80 for all 24 eyes and 0.60, 0.64, and 0.71 for experimental eyes only. The correlation between damage grade in the experimental eye and axonal survival using the TEM sampling method (Spearman's p = -0.677 for all animals and -0.827 for the subset of animals with full counts only) was lower than that with the full-count method (Spearman's p = -0.926). When axonal survival was less than 0.7, the sampling method always underestimated the extent of damage.CONCLUSIONS. The grading scheme had good inter- and intraobserver agreement, and high correlation with the TEM methods. It is a practical and time-saving method, requiring less than 1 minute per nerve and is an alternative to sampling methods that can yield significant errors.