Glaucoma, a leading cause of blindness worldwide, is a progressive optic neuropathy with characteristic structural changes in the optic nerve head reflected in the visual field. Even though a number of variables, including visual field defects, have been used by the experts in order to identify early glaucomatous damage, there is a need for computer-based methods that can detect glaucomatous damages at early stages so that treatment to prevent further progression can be instigated. The paper is mainly focused on the description of a methodology based on image processing techniques for the estimation of quantitative parameters to define vessel deformation in order to assist early detection of glaucoma.