In this article, we propose a new method for localizing optic disc in retinal images. Localizing the optic disc and its center is the first step of most vessel segmentation, disease diagnostic, and retinal recognition algorithms. We use optic disc of the first four retinal images in DRIVE dataset to extract the histograms of each color component. Then, we calculate the average of histograms for...

In this work, we have presented a novel method for detection of retinal image features, the optic disc and the fovea, from colour fundus photographs of dilated eyes for Computeraided Diagnosis(CAD) system. A saliency map based method was used to detect the optic disc followed by an unsupervised probabilistic Latent Semantic Analysis for detection validation. The validation concept is based on d...

OBJECTIVE To characterize variability in the identification of the macular center among retinopathy of prematurity (ROP) experts. METHODS A printed set of 25 wide-angle retinal images was compiled from infants at risk for ROP using a commercially available camera. Ten recognized ROP experts were asked to mark the macular center on each image. For each image, we measured the distance from the ...

PURPOSE To describe optic disc variables assessed by evaluation of clinical optic disc photographs and to compare sensitivity and specificity of these optic disc parameters in identifying patients with ocular hypertension who have nerve fiber layer defects and normal visual fields and patients with visual field defects. METHODS The study included 500 normal subjects, 132 patients with ocular ...

A new method for automatic optic disc localization and segmentation is presented. The localization procedure combines vascular and brightness information to provide the best estimate of the optic disc center which is the starting point for the segmentation algorithm. A detection rate of 99.58% and 100% was achieved for the Messidor and ONHSD databases, respectively. A simple circular approximat...

PURPOSE To compare the rates of detection of optic disc hemorrhages by clinical examination and by review of optic disc photographs at the Optic Disc Reading Center (ODRC), to assess the incidence of and the predictive factors for disc hemorrhages in the annual disc photographs of the Ocular Hypertension Treatment Study (OHTS), and to determine whether optic disc hemorrhages predict the develop...

Diabetic retinopathy and glaucoma are one of the major cause of blindness. Early stage segmentation and detection of optic disc may be of great help to ophthalmologist for treatment of patient before any serious complications. In this paper new methodology is proposed for the detection of the optical disk from the retinal images. Input image is first preprocessed using spatial average filtering...

purpose: to report a case of unilateral severe visual loss and bilateral optic disc cupping secondary to brain metastasis of bronchogenic carcinoma patient and findings: a 48 year-old woman presented with severe visual loss of left eye without redness or pain or any systemic findings .clinical findings included decreased visual acuity of left eye to 4 m cf and (+3) positive marcus-gunn reflex ....

The location of the optic disc is of critical importance in retinal image analysis. We improve on past approaches on optic disc detection by working in colour space and also by localising accurately the optic disc boundary using an automatically initialised snake. The key issue presented is a comparison of colour spaces for performing colour morphology to remove blood vessels and prepare the im...

A new method for the detection of blood vessels that improves the detection of exudates in fundus photographs. The method starts with pre-processing to enhance the input image. The initial estimation of exudates is obtained by segmenting the optic disc and blood vessels from the fundus image. In order to segment the optic disc and blood vessel separate algorithm were used. First, optic disc is ...