Foveal

About: Foveal is a research topic. Over the lifetime, 2652 publications have been published within this topic receiving 94120 citations.

Viewing verification systems

Abstract: A viewing verification system is disclosed that allows a user to view an image by providing a viewer for the image, determining the space bounded by the foveal-vision of the user, verifying whether substantially the entire meaningful portion of the image has been correlated to the space bounded by the foveal vision of the user.

Arrested Foveal Development in Preterm Eyes: Thickening of the Outer Nuclear Layer and Structural Redistribution Within the Fovea.

Abstract: Purpose The aim of this study was to define landmarks to better characterize foveal microstructure in normal subjects and in preterms with or without signs of immaturity, and to report on thickness changes of outer foveal layers following analysis of optical coherence tomography (OCT) B-scan images. Methods Selected eyes from eight young adults with a history of prematurity (24-33 weeks of gestation) and five controls were imaged using conventional and directional OCT. Retinal layer thickness analysis was performed at selected temporal eccentricities defined by the individual distance between two landmarks for each case, the foveal center and the foveal rim. Results The use of a foveal center and foveal rim landmark transformation enabled comparisons of interindividual B-scans at corresponding landmark positions in both controls and preterms. We found a 20% shorter foveal center to foveal rim distance in preterms with an immature fovea than in controls. Reflectometric and manual segmentation measurements showed increased thickness of inner retinal layers and photoreceptor cell body and outer plexiform layers centrally, but no observable change of photoreceptor inner and outer segment thickness. Conclusions Our landmark-based analysis of OCT images using reflectometry and manual segmentation provides complementary findings in comparisons of normal and immature foveal structures. We show a central thickness increase in the outer nuclear layer, outer plexiform layer, and postreceptor layers in preterms with signs of arrested foveal development. We found no indication of abnormal photoreceptor inner or outer segment development in preterms.

Elements of visual performance Contrast metric —visibility lobes—eye movements

Abstract: Visual performance is the combined result of foveal and extrafoveal perception per glimpse and saccadic eye movements. These processes are linked to the contrast metric of visibility as developed by Blackwell. The concept of visibility lobes per glimpse related to foveal visibility levels and simple strategies of ocular scanning provide an operational tool for analysis and design of visual tasks and lighting conditions.

Foveal hypoplasia and optical coherence tomographic imaging.

Abstract: Foveal hypoplasia is a retinal disorder in which there is a lack of full development of the morphology of the fovea. The optical coherence tomography (OCT) and functional findings are presented in relation to the underlying genetic and developmental conditions. Recent advancements of high-resolution OCT imaging have unveiled characteristics of foveal hypoplasia that were not detected by conventional imaging methods. An absence of a foveal pit does not necessarily imply poor visual acuity, and the maturation of the cone photoreceptors is important for the visual acuity. Regardless of the degree of the development of the inner retinal layers, the visual acuity can be preserved as in diseases such as Stickler syndrome that is a newly identified retinal disorder associated with foveal hypoplasia.