Automatic Grading of Severity of Diabetic Macular Edema Using Color Fundus Images

Diabetic macular edema (DME) is the main reason for vision loss in diabetic patients and results in blurring in the vision and leads to vision loss if left untreated. In this work, we have proposed an automatic unsupervised method to classify severity of diabetic macular edema in color fundus images. Particle Swarm Optimization (PSO) algorithm is made use of for effective segmentation of exudates. Optic disc and fovea are detected employing mathematical morphology. Region of macula is marked by Early Treatment Diabetic Retinopathy Studies (ETDRS) grading scale. Severity of disease such as normal, stage 1 or stage 2 of diabetic macular edema is detected by the location of exudates. The proposed method is evaluated using 100 images of publically available MESSIDOR database and performance figures of 82.5% for sensitivity, 100% for specificity and 93% for accuracy are obtained.