Psychophysical measurements of luminance and chromatic spatial and temporal contrast sensitivity in Duchenne muscular dystrophy.

Abstract

In children with Duchenne muscular dystrophy, color vision losses have been related to dystrophin deletions downstream of exon 30, which affect a dystrophin isoform, Dp260, present in the retina. To further evaluate visual function in DMD children, we measured spatial, temporal, and chromatic red-green and blue-yellow contrast sensitivity in two groups of DMD children with gene deletion downstream and upstream of exon 30. Psychophysical spatial contrast sensitivity was measured for low, middle, and high spatial frequencies with achromatic gratings and for low and middle frequencies with red-green and blue-yellow chromatic gratings. Temporal contrast sensitivity was also measured with achromatic stimuli. A reduction in sensitivity at all spatial luminance contrasts was found for the DMD patients with deletion downstream of exon 30. Similar results were found for temporal luminance contrast sensitivity. Red-green chromatic contrast sensitivity was reduced in DMD children with deletion downstream of exon 30, whereas blue-yellow chromatic contrast sensitivity showed no significant differences. We conclude that visual function is impaired in DMD children. Furthermore, we report a genotype-phenotype relationship because the visual impairment occurred in children with deletion downstream but not upstream of exon 30, affecting the retinal isoform of dystrophin Dp260.

ON and OFF Electroretinography and Contrast Sensitivity in Duchenne Muscular Dystrophy

“…In patients with gene alterations upstream of exon 30, which affect only the Dp427, these losses are either absent or less severe. 38,39 The intersubject variability in the responses to longduration flash stimuli is large; these are exclusively driven by the cones since the measurements are normally performed under light-adapted conditions. One alternative ERG protocol to evaluate ON and OFF retinal responses is the flicker ERG using sawtooth waveforms.…”

The Visual (dis)Function in Neurological Diseases

“…Our data also point to important maturational changes of the nervous system in infants with bronchopulmonary dysplasia, since they exhibit a delay in the appearance and quality of executable rights of eye movements compared with normal babies (Pereira & Costa, in press). Duchenne Muscle Dystrophy children had more evident impairments in their PC and a weaker in MC visual pathways but a normal KC pathway [77,78,87]. It is important to stress here that our studies contribute to understand the physiological and behavioral effects of different location sites of the lesions.…”

“…In our work [87], contrast sensitivity was also tested for temporally modulated stimuli. We found a reduction in the detection of luminance contrasts for the two lowest temporal modulations (i.e., 1 and 2 Hz).…”

Image Quality Assessment Based on Multi-Order Local Features Description, Modeling and Quantification

“…However, they only use the first-order derivative pattern for feature extraction which results in comparatively low accuracy of image quality quantification. As is well known, in image quality perception, HVS is more sensitive to detailed information than background in a scene [38]. That is to say, the highorder information (high-order characteristics, co-occurrence statistics etc.)…”