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Orientational Contrast Sensitivity and Chromatic Contrast Thresholds in Multiple Sclerosis
journal contributionposted on 2023-06-07, 19:11 authored by Timothy L Jackson, Gek L Ong, Lionel G Ripley
Purpose:To investigate abnormalities of orientational contrast sensitivity (CS) and chromatic contrast threshold (CCT) in multiple sclerosis (MS). Design:Case control study. Methods:Nine subjects (mean age, 42 ± 11 years; range, 20¿62 years) with MS, an expanded disability status scale of 3 or less, and normal visual acuity (VA) (logarithm of the minimum angle of resolution [logMAR] VA less than .1) in the tested eye were age-matched with 20 controls. Achromatic CS and CCT were measured using static, computer-generated sinusoidal gratings displayed on a high-resolution monitor. The CS and CCT of each subject were determined using a randomized double-staircase reversal algorithm; CS was measured at five spatial frequencies with horizontal orientation and three with vertical orientation; CCT was measured along the red-green and tritan confusion axes. The sensitivity thresholds of subjects were examined in relation to the mean sensitivity of controls for each spatial frequency. Results:Two subjects had loss of horizontal and vertical CS, and three had isolated vertical loss. When compared with the control mean, there were significant reductions in red-green (P = .016) and tritan (P = .016) discrimination thresholds. Conclusion:This study used a computerized psychophysical test designed to minimize many of the test errors associated with earlier studies. It provides confirmatory evidence that MS may be associated with a loss of orientational CS and color vision, in the absence of reduced VA.
JournalAmerican Journal of Ophthalmology
Department affiliated with
- Engineering and Design Publications
NotesThis paper further establishes that (tritan) colour-vision deficit is a useful measure of the progress of various neurological and ophthalmic conditions and that the Sussex Gratings Machine (SGM) and its derivative, the Sussex Colour Screener (SCS), are viable instruments for its assessment. More than 20 other publications in leading journals ( Am J Ophthal/IOVS etc) have been based on results collected with these machines. SCS machines have been adopted at various UK centres and in Frankfurt, where the machine was bought for a large-scale pharmacological study on the specific recommendation of Prof. Tooke of Exeter.
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