Optic nerve head segmentation

Reliable and efficient optic disk localization and segmentation are important tasks in automated retinal screening. General-purpose edge detection algorithms often fail to segment the optic disk due to fuzzy boundaries, inconsistent image contrast or missing edge features. This paper presents an algorithm for the localization and segmentation of the optic nerve head boundary in low-resolution images (about 20 /spl mu//pixel). Optic disk localization is achieved using specialized template matching, and segmentation by a deformable contour model. The latter uses a global elliptical model and a local deformable model with variable edge-strength dependent stiffness. The algorithm is evaluated against a randomly selected database of 100 images from a diabetic screening programme. Ten images were classified as unusable; the others were of variable quality. The localization algorithm succeeded on all bar one usable image; the contour estimation algorithm was qualitatively assessed by an ophthalmologist as having Excellent-Fair performance in 83% of cases, and performs well even on blurred image

A GPU-based Evolution Strategy for Optic Disk Detection in Retinal Images

La ejecución paralela de aplicaciones usando unidades de procesamiento gráfico (gpu) ha ganado gran interés en la comunidad académica en los años recientes. La computación paralela puede ser aplicada a las estrategias evolutivas para procesar individuos dentro de una población, sin embargo, las estrategias evolutivas se caracterizan por un significativo consumo de recursos computacionales al resolver problemas de gran tamaño o aquellos que se modelan mediante funciones de aptitud complejas. Este artículo describe la implementación de una estrategia evolutiva para la detección del disco óptico en imágenes de retina usando Compute Unified Device Architecture (cuda). Los resultados experimentales muestran que el tiempo de ejecución para la detección del disco óptico logra una aceleración de 5 a 7 veces, comparado con la ejecución secuencial en una cpu convencional.Parallel processing using graphic processing units (GPUs) has attracted much research interest in recent years. Parallel computation can be applied to evolution strategy (ES) for processing individuals in a population, but evolutionary strategies are time consuming to solve large computational problems or complex fitness functions. In this paper we describe the implementation of an improved ES for optic disk detection in retinal images using the Compute Unified Device Architecture (CUDA) environment. In the experimental results we show that the computational time for optic disk detection task has a speedup factor of 5x and 7x compared to an implementation on a mainstream CPU

Ultra-high density recording technologies

The Engineering Research Center in Data Storage Systems at Carnegie Mellon University in cooperation with the National Storage Industry Consortium has selected goals of achieving 10 Gbit/sq in. recording density in magnetic and magneto-optic disk recording and 1 terabyte/cubic in. magnetic tape recording technologies. This talk describes the approaches being taken and the status of research leading to these goals

Optic disk melanocytoma: bibliographic review

Melanocytoma of the optic disc is a well known variant of melanocytic nevus that usually occurs as a deeply pigmented lesion on the head of the optic disc. Historically, this tumor has often been confused with malignant melanoma. Histopathologically, it is composed of deeply pigmented round oval cells with abundant cytoplasm and small, round, bland nuclei. Melanocytomas is a benign, stationary tumors, with almost no propensity to undergo malignant transformation. Most cases that occur on the optic disc are visually asymptomatic, but they can cause an afferent pupillary and visual field defects. Importantly, it can exhibit malignant transformation into melanoma in 1 to 2% of the cases. The affected patients should have periodic follow up.O melanocitoma do disco óptico é bem conhecido como uma variante do nervo melanocítico que geralmente ocorre no disco óptico. Historicamente o tumor foi confundido com melanoma maligno. Histopatologicamente é composto por células redondas densamente pigmentadas com citoplasma abundante e pequenos nucléolos. O melanocitoma é considerado um tumor benigno, estacionário e com pouca predisposição de sofrer malignação. Na maioria dos casos são assintomáticos, mas podem apresentar defeitos pupilares e no campo visual. É importante salientar que a transformação maligna em melanoma ocorre em 1 a 2% dos casos. Assim, os oftalmologistas devem familiarizar-se com o melanocitoma do disco óptico e os pacientes afetados devem ser acompanhados periodicamente.Centro Médico AvimedUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL

Segmentation of the blood vessels and optic disk in retinal images

Retinal image analysis is increasingly prominent as a nonintrusive diagnosis method in modern ophthalmology. In this paper, we present a novel method to segment blood vessels and optic disk in the fundus retinal images. The method could be used to support nonintrusive diagnosis in modern ophthalmology since the morphology of the blood vessel and the optic disk is an important indicator for diseases like diabetic retinopathy, glaucoma, and hypertension. Our method takes as first step the extraction of the retina vascular tree using the graph cut technique. The blood vessel information is then used to estimate the location of the optic disk. The optic disk segmentation is performed using two alternative methods. The Markov random field (MRF) image reconstruction method segments the optic disk by removing vessels from the optic disk region, and the compensation factor method segments the optic disk using the prior local intensity knowledge of the vessels. The proposed method is tested on three public datasets, DIARETDB1, DRIVE, and STARE. The results and comparison with alternative methods show that our method achieved exceptional performance in segmenting the blood vessel and optic disk

Connecting the Retina to the Brain

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Work in the laboratory of LE is funded by the BBSRC [BB/J00815X/1] and the R.S. Macdonald Charitable Trust. Research in the laboratory of EH is funded by grants from the Regional Government [Prometeo2012-005], the Spanish Ministry of Economy and Competitiveness [BFU2010-16563] and the European Research Council [ERC2011-StG20101109].Peer reviewedPublisher PD