Structure-Oriented Transformer for retinal diseases grading from OCT images.

Retinal diseases are the leading causes of vision temporary or permanent loss. Precise retinal disease grading is a prerequisite for early intervention or specific therapeutic schedules. Existing works based on Convolutional Neural Networks (CNN) focus on typical locality structures and cannot capture long-range dependencies. But retinal disease grading relies more on the relationship between the local lesion and the whole retina, which is consistent with the self-attention mechanism. Therefore, the paper proposes a novel Structure-Oriented Transformer (SoT) framework to further construct the relationship between lesions and retina on clinical datasets. To reduce the dependence on the amount of data, we design structure guidance as a model-oriented filter to emphasize the whole retina structure and guide relation construction. Then, we adopt the pre-trained vision transformer that efficiently models all feature patches' relationships via transfer learning. Besides, to make the best of all output tokens, a Token vote classifier is proposed to obtain the final grading results. We conduct extensive experiments on one clinical neovascular Age-related Macular Degeneration (nAMD) dataset. The experiments demonstrate the effectiveness of SoT components and improve the ability of relation construction between lesion and retina, which outperforms the state-of-the-art methods for nAMD grading. Furthermore, we evaluate our SoT on one publicly available retinal diseases dataset, which proves our algorithm has classification superiority and good generality.