Automatic Segmentation and Estimation of Ischemic Regions in Oct Angiography Scans

Optical Coherence Tomography Angiography (OCTA) images represent the newest ophthalmic image modality with a great potential. They are characterized by allowing the precise non-invasive visualization of the retinal vasculature at different depths and resolutions. Given the relevance of the vascular analysis in this novel image modality, we propose the automatic segmentation and measurement of the existing ischemic areas that represent damaged regions of the eye fundus. In particular, we designed a methodology based in three main steps: image preprocessing, initial segmentation of ischemic regions by using active contours and final segmentation refinement. We obtained satisfactory results in the validation process, with a high separability between defined ischemic degrees in retinal vein occlusion patients. This fully automatic tool, with objectivity and reproducibility, provides an accurate measurement of the ischemic regions in real time, considering an issue where the manual analysis of the specialist is unfeasible in clinical practice routine.