Miura Naoki, Omodaka Kazuko, Kimura Koudai, Matsumoto Akiko, Kikawa Tsutomu, Takahashi Seri, Takada Naoko, Takahashi Hidetoshi, Maruyama Kazuichi, Akiba Masahiro, Yuasa Tetsuya, Nakazawa Toru
Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Graduate School of Science and Engineering, Yamagata University, Yamagata, Japan.
PLoS One. 2017 Oct 27;12(10):e0185573. doi: 10.1371/journal.pone.0185573. eCollection 2017.
The assessment of retinal nerve fiber layer defects (RNFLDs) is a useful part of glaucoma care. Here, we obtained en-face images of retinal layers below the inner limiting membrane (ILM) with swept source-optical coherence tomography (SS-OCT), and measured RNFLD angle with new software.
This study included 105 eyes of 105 normal tension glaucoma (NTG) patients (age, 59.8 ± 13.2). Exclusion criteria were best-corrected visual acuity < 0.5, axial length > 28 mm, non-glaucoma ocular disease, and systemic disease affecting the visual field. We obtained 12 x 9 mm 3D volume scans centered on the macula with SS-OCT (DRI OCT-1, Topcon), and from these scans, created 3 averaged en-face images, each comprising 7 horizontal en-face images (total thickness: 18.2 μm). We labeled these averaged images, according to their depth below the ILM, as en-face images 1 (shallowest), 2 (middle) and 3 (deepest). In each image, a circle was drawn centered on the disc, with a radius of half the distance between the centers of the disc and macula. The investigator marked points where the edge of the RNFLD intersected this circle, and RNFLD angle (RNFLDA) was calculated with new software. Finally, we analyzed the association between RNFLDA, cpRNFLT, weighted RGC count (wrgc) and Humphrey field analyzer (HFA)-measured mean deviation (MD) and hemifield total deviation (TD), both overall and in each hemifield.
En-face image 2 had the highest interclass reproducibility for measuring RNFLDA (intra-rater intraclass correlation coefficient (ICC): 0.988, inter-rater ICC: 0.962). The correlation coefficients with RNFLDA were: HFA MD, -0.60; superior TD, -0.73; inferior TD, -0.69; overall cpRNFLT, -0.27; superior hemifield cpRNFLT, -0.39; and inferior hemifield cpRNFLT, -0.53 (all p<0.001).
RNFLDA measured in SS-OCT images had high reproducibility and was correlated to glaucoma severity. Our new method may be a valuable future part of glaucoma care.
视网膜神经纤维层缺损（RNFLD）的评估是青光眼诊疗的一个有用部分。在此，我们利用扫频源光学相干断层扫描（SS-OCT）获取了内界膜（ILM）下方视网膜各层的正面图像，并使用新软件测量了RNFLD角度。
本研究纳入了105例正常眼压性青光眼（NTG）患者的105只眼（年龄59.8±13.2岁）。排除标准为最佳矫正视力<0.5、眼轴长度>28mm、非青光眼性眼病以及影响视野的全身性疾病。我们使用SS-OCT（DRI OCT-1，拓普康）以黄斑为中心获取了12×9mm的三维容积扫描图像，并从这些扫描图像中创建了3张平均正面图像，每张图像包含7张水平正面图像（总厚度：18.2μm）。我们根据这些平均图像在ILM下方的深度，将其标记为正面图像1（最浅）、2（中间）和3（最深）。在每张图像中，以视盘为中心画一个圆，其半径为视盘中心与黄斑中心之间距离的一半。研究者标记RNFLD边缘与该圆相交的点，并使用新软件计算RNFLD角度（RNFLDA）。最后，我们分析了RNFLDA、cpRNFLT、加权视网膜神经节细胞计数（wrgc）与Humphrey视野分析仪（HFA）测量的平均偏差（MD）和半视野总偏差（TD）之间的相关性，包括总体相关性以及每个半视野的相关性。
正面图像2在测量RNFLDA时具有最高的组内再现性（评估者内组内相关系数（ICC）：0.988，评估者间ICC：0.962）。与RNFLDA的相关系数分别为：HFA MD，-0.60；上方TD，-0.73；下方TD，-0.69；总体cpRNFLT，-0.27；上方半视野cpRNFLT，-0.39；下方半视野cpRNFLT，-0.53（均p<0.001）。
在SS-OCT图像中测量的RNFLDA具有高再现性，并且与青光眼严重程度相关。我们的新方法可能是未来青光眼诊疗中有价值的一部分。
