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For an understanding of the basis for psychophysical measurement of visual resolution, quantitative morphological studies of retinal neuronal architecture are needed. Here we report on cell densities and retinal ganglion cell:cone ratio (RGC:C) from the foveal border to the peripheral retina (34 degrees eccentricity). Quantitative estimates of RGC and C(More)
BACKGROUND A study was carried out to measure the displacement of retinal ganglion cells subserving the cones within the human fovea. METHODS Four human retinas were examined along the nasal or vertical hemi-meridians. Total displacement was estimated by adding the displacement due to fibres of Henle and bipolar cells, measured as the lateral extension of(More)
Published studies on humans and monkeys show discrepancies in the reported quantitative relationship between cones (C) and ganglion cells (G). Data on human foveal retina suggest that it cannot accommodate the midget on-off system in addition to other functional channels. Foveal cell densities along the vertical meridian (0-1.8 mm eccentricity) were(More)
A method is presented for quantitative measurements of the glare effect of light scattered in the ocular media. The contrast sensitivity function is measured with a television display system. A bright light source is introduced into the field of vision, and the resultant decrease in contrast sensitivity is mea-ured. It is further used to calculate a(More)
We present direct comparisons of resolution thresholds and quantitative estimates of retinal ganglion cell separation in humans with reported functional magnetic resonance imaging estimates of the human linear cortical magnification factor. Measurements of resolution thresholds (MAR), retinal ganglion cell (GC) densities, and linear cortical magnification(More)
Unexpected spinal anesthesia, occurring after peripheral nerve blocks close to the spine, may be caused by a centripetal spread of the local anesthetic along the injected nerve to the spinal cord. In order to analyze the pathway of such a spread, a radioactive local anesthetic mixed with a fluorescent dye was injected into difrerent compartments of the(More)
A patient with a cystic craniopharyngioma below the right optic nerve had several recurrences requiring surgery. Finally the cyst was connected with a subcutaneous reservoir by means of a fine catheter. Symptoms of optic nerve compression recurred more than 50 times during the following year, and were relieved within seconds upon drainage of the reservoir.(More)
PURPOSE Previous works show a pronounced disagreement on the reliability of stereo tests as screening tools for amblyopia and strabismus. This study's aim was to compare the ability of the Lang II, Frisby, Randot, Titmus, and TNO stereo tests to detect amblyopia and strabismus with visual acuity testing and cover testing. METHODS A total of 1035 school(More)
A method for quantitative measurements of disability glare in clinical practice is presented. Glare is induced by a circular fluorescent tube which surrounds a sinusoidal grating displayed on a monitor. The threshold contrast that is needed for detection of the grating is measured with and without presence of the glare light. This is repeated for several(More)