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Diagnosis retinal abnormalities in Optical Coherence Tomography (OCT) images assist ophthalmologist in the early detection and treatment of patients. To do this, different Computer Aided Diagnosis (CAD) methods based on machine learning and deep learning algorithms have been proposed. In this paper, wavelet scattering network is used to identify normal retina and four pathologies namely, Central Serous Retinopathy (CSR), Macular Hole (MH), Age-related Macular Degeneration (AMD) and Diabetic Retinopathy (DR). Wavelet scattering network is a particular convolutional network which is formed from cascading wavelet transform with nonlinear modulus and averaging operators. This transform generates sparse, translation invariant and deformation stable representations of signals. Filters in the layers of this network are predefined wavelets and not need to be learned which causes decreasing the processing time and complexity. The extracted features are fed to a Principal Component Analysis (PCA) classifier. The results of this research show the accuracy of 97.4% and 100% in diagnosis abnormal retina and DR from normal ones, respectively. We also achieved the accuracy of 84.2% in classifying OCT images to five classes of normal, CSR, MH, AMD and DR which outperforms other state of the art methods with high computational complexity. Clinical Relevance- Clinically, the manually checking of each OCT B-scan by ophthalmologists is tedious and time consuming and may lead to an erroneous decision specially for multiclass problems. In this study, a low complexity CAD system for retinal OCT image classification based on wavelet scattering network is introduced which can be learned by a small number of data.

Optical Coherence Tomography (OCT) is a non-invasive imaging technology that is widely applied for the diagnosis of retinal pathologies. In general, the structural information of retinal layers plays an important role in the diagnosis of various eye diseases by ophthalmologists. In this paper, by focusing on this information, we first introduce a new layer called the edge convolutional layer (ECL) to accurately extract the retinal boundaries in different sizes and angles with a much smaller number of parameters than the conventional convolutional layer. Then, using this layer, we propose the ECL-guided convolutional neural network (ECL-CNN) method for the automatic classification of the OCT images. For the assessment of the proposed method, we utilize a publicly available data comprising 45 OCT volumes with 15 age-related macular degeneration (AMD), 15 diabetic macular edema (DME), and 15 normal volumes, captured by using the Heidelberg OCT imaging device. Experimental results demonstrate that the suggested ECL-CNN approach has an outstanding performance in OCT image classification, which achieves an average precision of 99.43% as a three-class classification work. Clinical Relevance - The objective of this research is to introduce a new approach based on CNN for the automated classification of retinal OCT images. Clinically, the ophthalmologists should manually check each cross-sectional B-scan and classify retinal pathologies from B-scan images. This manual process is tedious and time-consuming in general. Hence, an automatic computer-assisted technique for retinal OCT image classification is demanded.