Biomaterial Database

Foveal and peripheral thresholds for detection and resolution of vanishing optotype tumbling E's. 1999

R S Anderson, and F A Ennis

Vision Science Research Group, School of Biomedical Sciences, University of Ulster at Coleraine, Londonderry, Northern Ireland. rs.anderson@ulst.ac.uk

We measured detection and resolution acuity for vanishing optotype tumbling E stimuli in both the fovea and at 30 degrees in the periphery to determine if peripheral resolution is sampling limited for this stimulus. In the fovea, where acuity is optically limited, detection and resolution were the same. At 30 degrees, however, detection was markedly better than resolution indicating that peripheral resolution is sampling limited for this stimulus. Detection acuity was higher when contrast was 90% rather than 40%, but resolution did not change with contrast. The vanishing optotype is a legitimate perimetric stimulus to measure retinal ganglion cell density provided the task is resolution and not detection.

UI	MeSH Term	Description	Entries
D011601	Psychophysics	The science dealing with the correlation of the physical characteristics of a stimulus, e.g., frequency or intensity, with the response to the stimulus, in order to assess the psychologic factors involved in the relationship.	Psychophysic
D005584	Fovea Centralis	An area approximately 1.5 millimeters in diameter within the macula lutea where the retina thins out greatly because of the oblique shifting of all layers except the pigment epithelium layer. It includes the sloping walls of the fovea (clivus) and contains a few rods in its periphery. In its center (foveola) are the cones most adapted to yield high visual acuity, each cone being connected to only one ganglion cell. (Cline et al., Dictionary of Visual Science, 4th ed)
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012684	Sensory Thresholds	The minimum amount of stimulus energy necessary to elicit a sensory response.	Sensory Threshold,Threshold, Sensory,Thresholds, Sensory
D014787	Vision Tests	A series of tests used to assess various functions of the eyes.	Test, Vision,Tests, Vision,Vision Test
D014792	Visual Acuity	Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.	Acuities, Visual,Acuity, Visual,Visual Acuities
D014794	Visual Fields	The total area or space visible in a person's peripheral vision with the eye looking straightforward.	Field, Visual,Fields, Visual,Visual Field
D015350	Contrast Sensitivity	The ability to detect sharp boundaries (stimuli) and to detect slight changes in luminance at regions without distinct contours. Psychophysical measurements of this visual function are used to evaluate VISUAL ACUITY and to detect eye disease.	Visual Contrast Sensitivity,Sensitivity, Contrast,Sensitivity, Visual Contrast