Predominant affection of the blue cone pathway in Parkinson's disease.

摘要: Luminance contrast sensitivity and colour thresholds were determined in 26 Parkinson patients 17 normal controls of comparable age. They psychophysically tested with a monitor system. Stimuli consisted Gaussian enveloped luminance modulated or (protan tritan axis) vertical sine wave gratings spatial frequency I cycle/°. The stimuli subtended 4° diameter. Thresholds using two alternative forced choice method. Three different experimental conditions explored: the detectability stationary gratings, moving at velocities 0, 2.5 5.0 cycles/s, horizontal square displacement 5 Hz for specified levels. Intergroup differences evaluated two-tailed t tests Satterthwaite corrections. Consistent significant between normals found static both dynamic conditions, condition. Protan much less apt to detect groups. We conclude that retinal deficit dopamine Parkinson's disease is reflected diminished centre/surround inhibition these changes are primarily apparent when vision along axis, because blue cones sparsely distributed.