[Contrast sensitivity is not only an additional complementary test].
Contrast sensitivity gives new insight on visual troubles encountered in ophthalmology. Indeed the measurement of this function yields some explanations on how vision is impaired by diseases frequently observed by clinicians. The deficits seen in strabismic amblyopes raise the possibility that the neural impairment in amblyopia is derived from a single continuum, varying in degree. The absence of stimulation of the size-selective detectors processing high spatial frequencies accounts for the shape of the contrast sensitivity curve in congenital nystagmus. Glaucomatous or multiple sclerosis patients show early deficits in medium range spatial frequencies where the sensitivity is the highest. These changes appear sometimes before any other investigation can detect them. When compared with physiological results using the same sinusoidal gradings as stimuli, contrast sensitivity gives reliable informations on how visual information is processed by the brain.
Nordmann
J P
JP
Service d'Ophtalmologie, Hôpital, Saint-Antoine, Paris.
Casanova
C
C
Laroche
L
L
Saraux
H
H
D000550:Amblyopia / Q000503:physiopathology; D015350:Contrast Sensitivity; D005901:Glaucoma / Q000503:physiopathology; D006801:Humans; D009103:Multiple Sclerosis / Q000503:physiopathology; D009759:Nystagmus, Pathologic / Q000151:congenital / Q000503:physiopathology; D014786:Vision Disorders / Q000503:physiopathology*; D014785:Vision, Ocular / Q000502:physiology
La sensibilité au contraste n'est pas simplement un examen complémentaire de plus.