Hepschke Jenny L, Martin Paul R, Fraser Clare L
Faculty of Health and Medicine, Save Sight Institute, The University of Sydney, Sydney, NSW, Australia.
Front Neurol. 2021 Aug 19;12:697923. doi: 10.3389/fneur.2021.697923. eCollection 2021.
Visual Snow (VS) is a disorder characterised by the subjective perception of black-and-white visual static. The aetiology of this condition is not known. In our previous work we suggested that there is a link between short-wave (S or "blue" cone) signals and severity of visual snow symptoms. Therefore we aimed to further characterise this potential link. Patients ( = 22) with classic VS based on the diagnostic criteria and healthy controls ( = 12), underwent Intuitive Colorimetry (IC) testing (Cerium Visual Technologies). Twelve hue directions (expressed as angle in CIE 1976 LUV space relative to D65) were rated on a five-point scale from preferred (relieving, positive score) to non-preferred (exacerbating, negative score), and overall preferred and non-preferred angles were chosen. A non-preferred violet region near the tritanopic confusion line / S-cone axis (267 deg.) was strongly associated with exacerbation of VS symptoms (range 250-310 deg, mean 276 ± 16, = 20, Rayleigh < 0.001). Two subjects with non-preferred region > 90 deg from mean were considered as outliers. Median rank at hue angle 270 deg was significantly lower than at angle 90 (-1.5 vs. 0.0, < 0.001, Wilcoxon non-parametric rank-sum test). Patients showed preference for one of two spectral regions which relieved VS symptoms: orange-yellow (range 50-110 deg., mean 79 ± 24, = 14) and turquoise-blue (range (210-250 deg., mean 234 ± 27, = 8). Our results show that visual snow symptoms are exacerbated by colour modulation that selectively increased levels of S-cone excitation. Because S-cone signals travel on primordial brain pathways that regulate cortical rhythms (koniocellular pathways) we hypothesis that these pathways contribute to the pathogenesis of this disorder.
视觉雪症（VS）是一种以主观感知到黑白视觉静态为特征的病症。这种病症的病因尚不清楚。在我们之前的研究中，我们提出短波（S或“蓝”锥）信号与视觉雪症状的严重程度之间存在联系。因此，我们旨在进一步明确这种潜在联系。根据诊断标准患有典型VS的患者（n = 22）和健康对照者（n = 12）接受了直观比色法（IC）测试（铈视觉技术公司）。从首选（缓解，正分）到非首选（加重，负分），对12个色调方向（以CIE 1976 LUV空间中相对于D65的角度表示）进行五分制评分，并选择总体首选和非首选角度。在近蓝色混淆线/S锥轴（267度）附近的一个非首选紫色区域与VS症状加重密切相关（范围250 - 310度，平均值276±16，n = 20，瑞利检验p < 0.001）。两名非首选区域与平均值偏差超过90度的受试者被视为异常值。色调角270度处的中位数秩显著低于90度处（-1.5对0.0，p < 0.001，威尔科克森非参数秩和检验）。患者对两个能缓解VS症状的光谱区域之一表现出偏好：橙黄色（范围50 - 110度，平均值79±24，n = 14）和蓝绿色（范围210 - 250度，平均值234±27，n = 8）。我们的结果表明，选择性增加S锥兴奋水平的颜色调制会加剧视觉雪症状。由于S锥信号沿着调节皮层节律的原始脑通路（侏儒细胞通路）传导，我们推测这些通路在这种病症的发病机制中起作用。
