Abstract: Digital retinal images are widely used for early detection of retinal, ophthalmic and systemic diseases because they provide a non-invasive window to the human circularity system and associated pathologies. Automated retinal image analysis is becoming an important screening tool for early detection of certain risks and diseases like diabetic retinopathy, hypertensive retinopathy, age related macular degeneration, glaucoma etc. This in turn can be used to reduce human errors or to provide services to remote areas. Optic disc localization and segmentation in digital fundus images may seem an easy task, due to the fact that the optic disc appears in most of the images as the brightest spot, approximately circular. Hence a number of algorithms and techniques are being developed for its segmentation. This paper reviews and compares the algorithms and techniques anteriorly proposed in order to develop better and more efficacious techniques and algorithms for detection of optic disc and fovea.
Keywords: Optic Disc, Fovea, Retinal images, Fundus image, Segmentation, Image processing.