Department of Diagnostic Imaging, National University Hospital Singapore, Singapore.
Department of Ophthalmology, National University Hospital Singapore, Singapore.
Asia Pac J Ophthalmol (Phila). 2020 Jan-Feb;9(1):39-43. doi: 10.1097/01.APO.0000617908.29733.84.
Conventional computed tomography (CT) exophthalmometry requires an intact lateral orbital wall and is therefore not feasible in patients who have undergone any form of lateral orbital wall surgery where the normal bony landmark may be lost or displaced. The purpose of our study is to validate an alternative method of CT exophthalmometry utilizing the posterior clinoid (PC) process as a new reference point that will allow for reproducible comparison of the anterior-posterior globe position in the preoperative and postoperative settings.
Cohort study.
This is a retrospective study of 48 patients with clinically diagnosed thyroid eye disease who had undergone cross-sectional CT imaging in the pre- or postoperative settings. CT exophthalmometry was performed using both the conventional interzygomatic method and our proposed PC process method on all pre- and postoperative CT imaging by two independent observers. Interobserver variability analysis was performed with intraclass correlation coefficient. Correlation and agreement between the two methods were analyzed with Pearson correlation coefficient and linear regression method. All analyses were conducted at 5% level of significance with Stata MP V14.
Interobserver variability analysis showed an intraclass correlation coefficient of >0.9 for both interzygomatic and PC methods. There is good correlation between the two different measurements observed in both the pre- and postoperative groups (r = 0.68 and r = 0.72, respectively, P < 0.001). Linear regression showed good agreement between the two different measurements with most of the points lying within the 95% limits.
Our new method agrees well with the conventional method and has the added benefit of being able to reliably assess the anterior-posterior globe position in patients who do not have intact lateral orbital walls after decompressive surgery.
传统的计算机断层扫描（CT）眼球突出度测量需要完整的外侧眶壁，因此对于任何形式的外侧眶壁手术的患者均不可行，因为正常的骨性标志可能丢失或移位。我们研究的目的是验证一种替代的 CT 眼球突出度测量方法，利用后床突（PC）作为新的参考点，以便在术前和术后环境中可重复比较前-后眼球位置。
队列研究。
这是一项回顾性研究，纳入了 48 例经临床诊断为甲状腺眼病的患者，这些患者在术前或术后均接受了横断面 CT 成像。在所有术前和术后 CT 成像上，两位独立观察者均使用传统的眶间颧骨法和我们提出的 PC 法进行 CT 眼球突出度测量。采用组内相关系数进行观察者间变异性分析。采用 Pearson 相关系数和线性回归法分析两种方法之间的相关性和一致性。所有分析均在 5%水平进行，使用 Stata MP V14 软件进行。
观察者间变异性分析显示，眶间颧骨法和 PC 法的组内相关系数均>0.9。两种不同的测量方法在术前和术后组中均具有良好的相关性（r=0.68 和 r=0.72，分别，P<0.001）。线性回归显示两种不同的测量方法具有良好的一致性，大多数点都在 95%的限制范围内。
我们的新方法与传统方法吻合良好，并且具有在减压手术后没有完整的外侧眶壁的患者中可靠地评估前-后眼球位置的额外优势。
