Eye Center, Medical Center, Faculty of Medicine, University of Freiburg, Killianstrasse 5, 79106, Freiburg, Germany.
BMC Ophthalmol. 2021 Jan 12;21(1):31. doi: 10.1186/s12886-020-01799-x.
Precise optic disc size measurements based on anatomically exact disc margins are fundamental for a correct assessment of glaucoma suspects. Computerized imaging techniques, such as confocal-scanning-laser-tomography (CSLT), which applies operator defined boundaries and optical-coherence-tomography (OCT), which incorporates an alternative detectable landmark (Bruch's-membrane-opening (BMO)), have simplified the planimetry of the optic disc and BMO-area, respectively. This study's objectives are to compare both modalities for area and to define a threshold for macro-BMO using BMO-OCT.
Retrospectively, patients that simultaneously received CSLT and BMO-OCT scans were included. Their images were correlated and agreement was determined using Bland-Altman-analysis. The diagnostic power of a macro-BMO threshold using OCT was derived after creating a receiver-operating-characteristics-curve using the well-established analogous CSLT threshold (2.43 mm).
Our study included 373 eyes with a median optic disc area by CSLT/ BMO-area by OCT of 2.56 mm and 2.19 mm respectively. The Bland-Altman-analysis revealed a systematic deviation with a diverging tendency with increasing area, which enabled the creation of the following mathematical relation: disc-area (CSLT)*0.73 + 0.3 = BMO-area (OCT). BMO-area of 2.19 mm showed the best diagnostic power for identifying macro-BMOs using OCT (sensitivity: 75%, specificity: 86%).
Area measurements (CSLT optic disc area vs. BMO-area by OCT) showed a systematic deviation with a divergent tendency with increasing size. Our mathematical equation offers an estimated comparison of these anatomically diverse entities. Considering BMO-OCT´ anatomical accuracy, the 2.19 mm threshold may improve discernment between glaucoma suspects and norm variants.
基于解剖学上准确的视盘边缘进行精确的视盘尺寸测量，对于正确评估青光眼患者至关重要。计算机成像技术，如共焦扫描激光断层扫描（CSLT），它应用操作员定义的边界，以及光学相干断层扫描（OCT），它结合了另一个可检测的地标（Bruch 膜开口（BMO）），分别简化了视盘和 BMO 区域的平面测量。本研究的目的是比较这两种模式的面积，并使用 BMO-OCT 为宏观 BMO 定义一个阈值。
回顾性地纳入同时接受 CSLT 和 BMO-OCT 扫描的患者。通过 Bland-Altman 分析对他们的图像进行相关和一致性确定。通过创建使用既定的类似 CSLT 阈值（2.43mm）的接收者操作特性曲线，得出使用 OCT 检测宏观 BMO 的阈值的诊断能力。
我们的研究包括 373 只眼睛，CSLT 测量的视盘面积中位数/通过 OCT 测量的 BMO 面积中位数分别为 2.56mm 和 2.19mm。Bland-Altman 分析显示存在系统偏差，随着面积的增加呈现发散趋势，这使得以下数学关系得以建立：视盘面积（CSLT）*0.73+0.3=BMO 面积（OCT）。使用 OCT 检测 2.19mm 的 BMO 面积显示出最佳的诊断能力，可识别出宏观 BMO（敏感性：75%，特异性：86%）。
面积测量（CSLT 视盘面积与 BMO 面积）显示出系统偏差，随着尺寸的增加呈现发散趋势。我们的数学方程提供了对这些解剖学上不同实体的估计比较。考虑到 BMO-OCT 的解剖学准确性，2.19mm 的阈值可能有助于区分青光眼患者和正常变异者。
