Multi-Level Dual-Attention Based CNN for Macular Optical Coherence Tomography Classification

In this letter, we propose a multi-level dual-attention model to classify two common macular diseases, age-related macular degeneration (AMD) and diabetic macular edema (DME) from normal macular eye conditions using optical coherence tomography (OCT) imaging technique. Our approach unifies the dual-attention mechanism at multi-levels of the pre-trained deep convolutional neural network (CNN). It provides a focused learning mechanism by taking into account both multi-level features based attention focusing on the salient coarser features and self-attention mechanism attending higher entropy regions of the finer features. Our proposed method enables the network to automatically focus on the relevant parts of the input images at different levels of feature subspaces. This leads to a more locally deformation-aware feature generation and classification. The proposed approach does not require pre-processing steps such as extraction of region of interest, denoising, and retinal flattening, making the network more robust and fully automatic. Experimental results on two macular OCT databases show the superior performance of our proposed approach as compared to the current state-of-the-art methodologies.