Locally adaptive probabilistic models for global segmentation of pathological OCT scans

Abstract

Segmenting retinal tissue deformed by pathologies can be challenging. Segmentation approaches are often constructed with a certain pathology in mind and may require a large set of labeled pathological scans, and therefore are tailored to that particular pathology. We present an approach that can be easily transfered to new pathologies, as it is designed with no particular pathology in mind and requires no pathological ground truth. The approach is based on a graphical model trained for healthy scans, which is modified locally by adding pathology-specific shape modifications. We use the framework of sum-product networks (SPN) to find the best combination of modified and unmodified local models that globally yield the best segmentation. The approach further allows to localize and quantify the pathology. We demonstrate the flexibility and the robustness of our approach, by presenting results for three different pathologies: diabetic macular edema (DME), age-related macular degeneration (AMD) and non-proliferative diabetic retinopathy.