Department of Ophthalmology and Visual Sciences, Dalhousie University and Nova Scotia Health Authority, Halifax, Nova Scotia, Canada.
Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
Br J Ophthalmol. 2024 May 21;108(6):807-811. doi: 10.1136/bjo-2023-323222.
Histological evidence indicates that the earliest structural changes to the optic nerve head (ONH) in glaucoma occur in the lamina cribrosa (LC) and its interface with the sclera. However, clinical imaging of these structures remains challenging. We compared the visibility of deep ONH structures with newer iterations of spectral-domain (SD) and swept-source (SS) optical coherence tomography (OCT).
Twelve patients with open-angle glaucoma were imaged with SD-OCT with 24 radial B-scans centred on Bruch's membrane opening (BMO) and SS-OCT with a horizontal and vertical raster scan pattern containing five lines each, centred on the ONH. Single best-matched horizontal and vertical scans from the two modalities were selected and exported. Three independent observers masked to modality determined if BMO, posterior choroid surface, anterior scleral canal opening and anterior and posterior LC insertions into the sclera were detectable in the matched B-scan images. We determined the interobserver agreement and concordance in detecting each structure with the two OCT imaging modalities.
There was a high interobserver agreement with both SS-OCT and SD-OCT (inter-item correlations: 0.81-0.93 and 0.77-0.82, respectively). There was a consistent tendency for higher overall detection rates with SS-OCT, however, the differences failed to reach statistical significance. With respect to individual structures, only the posterior LC insertion in the nasal quadrant was statistically different, with a detection rate of 13 and 6 (pooled out of a total of 36 across the three observers) with SS-OCT and SD-OCT, respectively (p=0.04).
Overall, both SS-OCT and SD-OCT showed statistically equivalent visualisation of ONH structures, however, SS-OCT tended to have higher visualisation rates.
组织学证据表明，青光眼视神经头（ONH）最早的结构变化发生在筛板（LC）及其与巩膜的交界处。然而，这些结构的临床成像仍然具有挑战性。我们比较了新一代的光谱域（SD）和扫频源（SS）光学相干断层扫描（OCT）对深 ONH 结构的可视性。
对 12 例开角型青光眼患者进行了 SD-OCT 成像，共 24 条以 Bruch 膜开口（BMO）为中心的放射状 B 扫描，以及 SS-OCT 成像，包含 5 条每条线的水平和垂直光栅扫描模式，以 ONH 为中心。从两种模式中选择并导出单个最佳匹配的水平和垂直扫描。三名独立的观察者对模态进行了遮蔽，以确定在匹配的 B 扫描图像中是否可以检测到 BMO、后脉络膜表面、前巩膜管开口以及 LC 的前、后插入部到巩膜。我们确定了两种 OCT 成像模式检测每个结构的观察者间一致性和一致性。
SS-OCT 和 SD-OCT 的观察者间一致性均较高（项间相关系数：0.81-0.93 和 0.77-0.82）。SS-OCT 的整体检测率较高，但差异无统计学意义。就个别结构而言，只有鼻象限的后 LC 插入具有统计学差异，SS-OCT 和 SD-OCT 的检测率分别为 13 和 6（三个观察者共 36 个中的总和）（p=0.04）。
总体而言，SS-OCT 和 SD-OCT 对 ONH 结构的可视化效果均具有统计学等效性，但 SS-OCT 倾向于具有更高的可视化率。
