Abstract：
Proper estimation of the cup-to-disc ratio (C/D ratio) plays a significant role in ophthalmic examinations, and it is urgent to improve the efficiency of C/D ratio automatic measurement. Therefore, we propose a new method for measuring the C/D ratio of OCTs in normal subjects. Firstly, the end-to-end deep convolution network is used to segment and detect the inner limiting membrane (ILM) and the two Bruch\'s membrane opening (BMO) terminations. Then, we introduce an ellipse fitting technique to post-process the edge of the optic disc. Finally, the proposed method is evaluated on 41 normal subjects using the optic-disc-area scanning mode of three machines: BV1000, Topcon 3D OCT-1, and Nidek ARK-1. In addition, pairwise correlation analyses are carried out to compare the C/D ratio measurement method of BV1000 to existing commercial OCT machines as well as other state-of-the-art methods. The correlation coefficient between the C/D ratio calculated by BV1000 and the C/D ratio calculated by manual annotation is 0.84, which indicates that the proposed method has a strong correlation with the results of manual annotation by ophthalmologists. Moreover, in comparison between BV1000, Topcon and Nidek in practical screening among normal subjects, the proportion of the C/D ratio less than 0.6 calculated by BV1000 accounts for 96.34%, which is the closest to the clinical statistics among the three OCT machines. The above experimental results and analysis show that the proposed method performs well in cup and disc detection and C/D ratio measurement, and compared with the existing commercial OCT equipment, the C/D ratio measurement results are relatively close to reality, which has certain clinical application value.
摘要：
正确估计杯盘比（C/D比）在眼科检查中起着重要作用，迫切需要提高C/D比自动测量的效率。因此,我们提出了一种测量正常人OCTC/D比的新方法。首先,端到端深度卷积网络用于分割和检测内界膜（ILM）和两个布鲁赫膜开口（BMO）终止。然后，我们引入椭圆拟合技术对视盘边缘进行后处理。最后,所提出的方法使用三台机器的视盘区扫描模式对41名正常受试者进行评估:BV1000,Topcon3DOCT-1和NidekARK-1.此外,进行了成对相关性分析，以将BV1000的C/D比测量方法与现有的商用OCT机器以及其他最先进的方法进行比较。BV1000计算的C/D比与人工标注计算的C/D比之间的相关系数为0.84,表明所提出的方法与眼科医生人工标注的结果具有很强的相关性。此外，在正常受试者的实际筛查中，BV1000、Topcon和Nidek之间的比较，BV1000计算的C/D比小于0.6的比例占96.34%，这是三个OCT机器中最接近的临床统计数据。以上实验结果和分析表明,该方法在杯盘检测和C/D比测量中,与现有的商用OCT设备相比，C/D比测量结果与实际比较接近，具有一定的临床应用价值。
