Clinical and technical perspective of glaucoma detection using OCT and fundus images: A review

Glaucoma is an eye problem that affects the retina and weakens the nerve cells that assist in visual recognition. This disease can be the cause of blindness and visual impairment if not treated earlier. Increase in Intraocular pressure (IOP) is the main cause for glaucoma presence and succession. The diameter of the optic cup within optic disc region is increased due to the excessive retinal pressure. The increased cup to disc ratio (CDR) results in the loss of optic nerve fibers that are connected to the retina by disc area. The thickness of the rim area between the disc and cup area as neuro-retinal rim (NRR) and CDR are important structural features for differentiating between a non-glaucomatous and a glaucomatous eye. Greater CDR is observed for glaucomatous eye analysis because of less number of optic fibers in the rim area. The widely used parameters as CDR and NRR are used in fundus images, and cup depth and retinal layers (retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness are the features calculated for glaucoma diagnosis in optical coherence tomography (OCT) imaging. The objective of the paper is to present the state of art methods for glaucoma detection that assist in the progressive development of computer-aided systems.