Diabetic Retinopathy Diagnosis Through Computer-Aided Fundus Image Analysis: A Review

Diabetic retinopathy, initially symptomless medical condition of diabetes, is one of the significant reasons of vision impairment all over the world. The early detection and diagnosis can reduce the incidence of severe vision loss and improve the efficiency of treatment. Fundus imaging, a non-invasive diagnosis method, is initial and widely used mode for analysing diabetic retinopathy. However, the precision of fundus imaging-based diagnosis of retinal disease is vastly dependent on experience and knowledge of ophthalmologists. Computer-aided diagnostic systems designed for retinal fundus images aid quick diagnosis, offer an external viewpoint during decision making, and serves as an important way of assessing treatment response to retinal diseases. In this paper, firstly the issues faced by ophthalmologists in characterization of various landmark structures and retinal lesions related to diabetic retinopathy by ophthalmologists are stated. Secondly, a comprehensive review of the state-of-the-art methods on landmark structures detection and segmentation, retinal lesions segmentation and diabetic retinopathy screening methods with retinal fundus images is presented. A concise tabular summary of each section comparing various methods, related retinal image databases, performance parameters, advantages, and disadvantages of the published methods is also exhibited. Finally, the main findings with focus to current challenges and ways for further improvement with respect to research gaps are discussed and concluded.