Aims/background: Abnormal blood flow dynamics are believed to contribute to the development of retinal microvascular disease in patients infected with human immunodeficiency virus (HIV). In this study, the scanning laser ophthalmoscope (SLO) was used, combined with fluorescein angiography, to measure retinal blood flow indices in HIV seropositive patients.
Methods: Arteriovenous passage time (AVP) and perifoveal capillary blood flow velocity (CFV) were measured in 23 HIV infected patients and 23 control subjects with SLO fluorescein angiography.
Objective: To characterize a distinct disorder of the optic nerve that manifests as recurrent episodes of acute, monocular disc edema and macular star formation.
Design: Description of the clinical features and laboratory findings in a group of patients with this disorder.
Setting: Referral center.
Graefes Arch Clin Exp Ophthalmol
September 1991
The analysis of vertical saccades by electrooculography (EOG) is limited by the presence of waveform artifacts that occur with both upward and downward saccades. The artifacts have been shown to increase the calculated velocities of upward saccades. For better evaluation of the nature of these artifacts, voluntary vertical saccades were recorded by EOG and magnetic search coil in five normal subjects and by EOG only in two patients who had previously undergone enucleation.
View Article and Find Full Text PDFA color television display was used to measure thresholds for mixtures of red and green on a white background; red and green components could be either incremental, decremental or zero. Ellipses are fitted to a plot of green contrast as a function of red contrast, and it is argued that the length of the ellipse is a measure of red-green color discrimination and the width of the ellipse is a measure of luminance discrimination. It is shown that the technique reliably distinguishes normals from congenital color defectives and also protan from deutan subjects.
View Article and Find Full Text PDFA color television display can be used to determine color and brightness discrimination thresholds using identical adaptation conditions and experimental technique. The color discrimination threshold is measured by using an equiluminous test spot--i.e.
View Article and Find Full Text PDFAm J Optom Physiol Opt
March 1983
Three sets of pseudoisochromatic plates were evaluated by photometry and colorimetry. The luminance contrast between the figure and background was measured and compared with a contrast detection threshold. The chromaticity coordinates of the figure and background were evaluated on the basis of how closely they approached a dichromatic line of confusion.
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