purpose: to report a case who had optic disc duplication, a rare congenital disorder characterized by two well-defined discs in one eye. case report: a 19 months-old child presented with unilateral epiphora in the right eye since birthday. the right eye was smaller than the left eye and mild ptosis was apparent. nasolacrimal duct probing was performed under general anesthesia. the examination r...

OBJECTIVE To determine the correspondence between optic disc margins evaluated using disc photography (DP) and optical coherence tomography (OCT). METHODS From May 1, 2005, through November 10, 2005, 17 healthy volunteers (17 eyes) had raster scans (180 frames, 501 samplings per frame) centered on the optic disc taken with stereo-optic DP and high-speed ultrahigh-resolution OCT (hsUHR-OCT). T...

PURPOSE To evaluate the ophthalmoscopic appearance of the normal optic disc, parapapillary region, and retinal nerve fiber layer in rhesus monkeys. METHODS Color stereo fundus photographs of 17 normal eyes of 17 rhesus monkeys aged between 13 and 23 years were morphometrically evaluated. RESULTS The neuroretinal rim was significantly (P: < 0.008) broadest in the inferior disc region followe...

In the automatic analysis of retinal images for diagnosing various eye diseases such as diabetic retinopathy, glaucoma etc. the automatic detection of the optic disc is a crucial step. Before processing the fundus image for detecting any type of retinal disease it is necessary to mask out the anatomical features of eye so that they will not be mistaken as abnormality. Optic disc often considere...

In Diabetic retinopathy, early detection as well as periodic screening helps in reducing the progress of disease and in preventing the subsequent loss of visual capability. The system extracts some retinal features, such as optic disc, retinal tissue for easier segmentation of dark spot lesions in the fundus images. To improve the detection optic disc in diabetic retinopathy image, a morphologi...

Optic disc detection and segmentation is one of the key elements for automatic retinal disease screening systems. The aim of this survey paper is to review, categorize and compare the optic disc detection algorithms and methodologies, giving a description of each of them, highlighting their key points and performance measures. Accordingly, this survey firstly overviews the anatomy of the eye fu...

This paper describes two complementary methods for computer analysis of the optic disc in glaucoma. The objective of both techniques is to detect and monitor changes in the optic disc through the use of digital image processing techniques that allow user intervention. In the first method, optic disc photographs from successive years are digitized, scaled and registered (aligned) with each other...

This paper presents a novel approach to the fast localization and extraction of optic disc from fundus images of the human retina. Optic disc continues to be a major landmark for fundus image registration and is indispensible for the understanding of retinal fundus images. For the detection of optic disc, we first decompose the image into its bit planes. The lower order bit planes are found to ...

Diabetic retinopathy is a disease, which forms a severe threat on sight. It may reach to blindness among working age people. By analyzing and detecting vasculature structures in retinal image the diabetes can be detected in advanced stages by comparing its states of retinal blood vessels. In blood vessel segmentation approach, computer based retinal image analysis can be used to extract the ret...

On the research work leading to automatic detection of optic disc from retinal images is very essential and crucial for expert ophthalmologists to diagnose diseases. Many of techniques can achieve good performance on retinal feature that is clearly visible. Unfortunately, it is a normal situation that the color retinal images in Thailand are poor-quality images. The existing algorithm cannot de...