Retina Service, Farabi Eye Hospital, Tehran University of Medical Sciences, Qazvin Square, South Kargar Street, Tehran, 1336616351, Iran.
Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences and Research Center for Science and Technology in Medicine, Tehran, Iran.
Sci Rep. 2021 Apr 19;11(1):8505. doi: 10.1038/s41598-021-87954-w.
Fuchs uveitis (FU) is a chronic and often unilateral ocular inflammation and characteristic iris atrophic changes, other than heterochromia, are common in FU and are key to the correct diagnosis in many cases. With the advent of anterior segment optical coherence tomography (AS-OCT), some investigators attempted to quantitatively study these atrophic changes; mostly by introducing various methods to measure iris thickness in AS-OCT images. We aimed to present an automated method in an observational case series to measure the smoothness index (SI) of the iris surface in AS-OCT images. The ratio of the length of the straight line connecting the most peripheral and central points of the anterior iris border (in nasal and temporal sides) to the actual length of this border on AS-OCT images, was defined as SI. In a uveitis referral center, twenty-two eyes of 11 patients with unilateral Fuchs uveitis (FU) (7 female) and 22 eyes of 11 healthy control subjects underwent AS-OCT imaging. Image J and a newly developed MATLAB algorithm were used for manual and automated SI measurements, respectively. Agreement between manual and automated measurements was evaluated with Bland-Altman analysis and interclass correlation coefficient. The inter-eye difference of SI was compared between the FU group and the control group. Automated mean overall SI was 0.868 ± 0.037 and 0.840 ± 0.039 in FU and healthy fellow eyes, respectively (estimated mean difference = - 0.028, 95% CI [- 0.038, - 0.018], p < 0.001). Bland- Altman plots showed good agreement between two methods in both healthy and FU eyes. The interclass correlation coefficient between the manual and automated measurements in the FU and healthy fellow eyes was 0.958 and 0.964, respectively. The inter-eye difference of overall SI was 0.029 ± 0.015 and 0.012 ± 0.008 in FU group and control group, respectively (p = 0.01). We concluded that the automated algorithm can rapidly and conveniently measure SI with results comparable to the manual method.
非感染性前部葡萄膜炎（FU）是一种慢性且常为单侧的眼部炎症，除了虹膜异色症外，其特征性的虹膜萎缩性改变也很常见，在许多情况下，这些改变是正确诊断的关键。随着眼前段光学相干断层扫描（AS-OCT）的出现，一些研究人员试图对这些萎缩性改变进行定量研究；主要通过引入各种方法来测量 AS-OCT 图像中的虹膜厚度。我们旨在通过一项观察性病例系列研究，提出一种自动方法来测量 AS-OCT 图像中虹膜表面的平滑指数（SI）。该方法定义为从前部虹膜边界最外周和中央点连接的直线长度与 AS-OCT 图像上该边界的实际长度之比。在葡萄膜炎转诊中心，22 只患有单侧 Fuchs 葡萄膜炎（FU）的 11 名患者（7 名女性）和 22 只健康对照者的眼睛接受了 AS-OCT 成像。使用 Image J 和新开发的 MATLAB 算法分别进行手动和自动 SI 测量。通过 Bland-Altman 分析和组内相关系数评估手动和自动测量之间的一致性。比较 FU 组和对照组之间 SI 的双眼间差异。自动平均整体 SI 分别为 0.868 ± 0.037 和 0.840 ± 0.039，在 FU 和健康对照组眼中（估计平均差异为 -0.028，95%CI[-0.038，-0.018]，p<0.001）。Bland-Altman 图显示两种方法在健康眼和 FU 眼中均具有良好的一致性。FU 和健康对照组手动和自动测量之间的组内相关系数分别为 0.958 和 0.964。FU 组和对照组的整体 SI 双眼间差异分别为 0.029 ± 0.015 和 0.012 ± 0.008（p=0.01）。我们得出结论，自动算法可以快速方便地测量 SI，其结果与手动方法相当。
