An automatic system for the analysis of vascular lesions in retinal images

In this work a computational approach for detecting and quantifying diabetic retinopathy is proposed. Particular attention has been paid to the study of Foveal Avascular Zone (FAZ). In fact, retinal capillary occlusion produces a FAZ enlargement. Moreover, the FAZ is characterized by qualitative changes showing an irregular contour with notchings and indentations. On this ground, the authors´ aim was the development of an automatic system for the quantitative morphological evaluation of the vascular lesions of the fundus oculi occurring in diabetic subjects. The authors propose an automatic segmentation procedure derived from the theory of active contour, also known as snakes, along with genetic optimization. Then they tried to extract features which can capture not only the size of the object, but also its shape and spatial orientation. The authors used a set of region and boundary moments to obtain a FAZ description which is complete enough for diagnostic purposes and in order to assess the effectiveness of moment descriptors they performed several classification experiments to discriminate diabetic from non-diabetic subjects