Glaucoma Detection in Color Fundus Images Using Cup to Disc Ratio

-----------------------------------------------ABSTRACT---------------------------------------------------------GLAUCOMA is a group of diseases that can damage the eye’s optic nerve and result in vision loss and permanent blindness. Glaucoma is a disease characterized by elevated intraocular pressure (IOP). This increased IOP leads to damage of optic nerve axons at the back of the eye, with eventual deterioration of vision. CDR is a key indicator for the detection of glaucoma. The ratio of the size of the optic cup to the optic disc, also known as the cup-to-disc ratio (CDR), is one of the important clinical indicators of glaucoma, and is currently determined manually by trained ophthalmologists, limiting its potential in mass screening for early detection. In this paper, we propose a method to calculate the CDR automatically. Preprocessing methods such as anisotropic filtering have been performed. Automatic disc extraction is done using 3 techniques 1) Edge detection method, 2) Optimal thresholding method, and 3) Manual threshold analysis. Threshold levelset method is used for the detection of cup. The methods have been tested on the images in the publicly available DRIVE database.