Retinal Blood Vessels Differentiation for Calculation of Arterio-Venous Ratio

Samra Irshad, M. Usman Akram, Sara Ayub, Anaum Ayaz

Abstract: Hypertensive Retinopathy (HR) is an eye disease occurs due to high blood pressure. This disease primarily damages the blood vessels in retina by altering the vessel caliber. The damage is evaluated by calculation of Arterio-venous Ratio (AVR), which quantifies the change in diameter of retinal blood vessels. It is basically the ratio of arterioles to venules diameter. In order to calculate AVR for an automatic diagnosis of HR, the vascular characterization is an essential step. This paper presents an automatic system for retinal vessel classification which is based on novel combination of intensity and gradient based features. The automated system first segments the retinal vessels, then extracts features and finally classifies the vessels as arteries and veins. The proposed system is tested and validated on locally gathered fundus image database, taken from AFIO, Pakistan. The proposed approach provides an accuracy of 93.49 % and 93.47 % for veins and arteries, respectively.