Spatio-temporal selectivity of loss of colour and luminance contrast sensitivity with multiple sclerosis and optic neuritis

• Published in: Ophthalmic & physiological optics 2005-01, Vol.25 (1), p.57-65
• Main Authors: Flanagan, Patrick, Markulev, Connie
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Color Perception Tests - methods; Color Vision Defects - diagnosis; Color Vision Defects - etiology; colour vision; Contrast Sensitivity; Diseases of visual field, optic nerve, optic chiasma and optic tracts; Female; Humans; luminance vision; Male; Medical sciences; Middle Aged; multiple sclerosis; Multiple Sclerosis - complications; Multiple Sclerosis - psychology; Multiple sclerosis and variants. Guillain barré syndrome and other inflammatory polyneuropathies. Leukoencephalitis; Neural Pathways - physiopathology; Neurology; Ophthalmology; optic neuritis; Optic Neuritis - complications; Optic Neuritis - psychology; Photic Stimulation - methods; Psychophysics; Sensory Thresholds
• ISSN: 0275-5408; 1475-1313
• DOI: 10.1111/j.1475-1313.2004.00252.x

Colour and luminance‐contrast thresholds were measured in the presence of dynamic Random Luminance‐contrast Masking (RLM) in individuals who had had past diagnoses of optic neuritis (ON) some of whom have progressed to a diagnosis of multiple sclerosis (MS). To explore the spatio‐temporal selectivity of chromatic and luminance losses in MS/ON, thresholds were measured using three different sizes and modulation rates of the RLM displays: small checks modulating slowly, medium‐sized checks with moderate modulation and large checks modulating rapidly. The colour of the chromatic stimuli used were specified in a cone‐excitation space to measure relative impairments in red–green and blue–yellow chromatic channels. These observers showed chromatic thresholds along the L/(L + M) axis that were higher than those along the S‐cone axis for all display sizes/modulation rates and both red‐green and blue‐yellow colour thresholds were higher than luminance‐contrast thresholds. The principal change in thresholds with spatio‐temporal changes in the display was a reduction in thresholds for L/(L + M) and S‐cones with increasing check size and modulation rate. However, luminance contrast thresholds did not change with display size/rate. These results are consistent with MS/ON selectively affecting processing in colour pathways rather than in the magnocellular pathway, and that within the colour pathways neurones with opposed L‐ and M‐cone inputs are more damaged than colour‐opponent neurons with input from S‐cones.