Colour discrimination in post-COVID-19 observers assessed by the Farnsworth-Munsell 100-Hue test

Post-COVID-19, recorded were various ophthalmological symptoms and visual impairment. We hypothesised that colour vision may be affected too. We assessed colour discrimination using the Farnsworth-Munsell 100 Hue test (FM-100) in individuals, who have had COVID-19 (N=77; 18–68 years).The following supporting information can be downloaded at: https://figshare.com/s/6900f26033c71afc7888. <b>Data</b> analysed in this study. <b>Appendix 1:</b> Error distribution in the FM-100 diagram for post-COVID participants (N=77). <b>Appendix 2:</b> Computer program for calculating major and minor axes for the D-15, D-15d and FM 100-Hue tests.<b>Supplementary Materials: Table S1</b> – Demographic characteristics of post-COVID participants, and self-reported duration of the illness and symptoms.<b>Table S2</b> – FM-100 parameters for post-COVID participants: total error score (TES), error scores for four FM-100 boxes (AES, BES, CES, DES), and partial error scores (PES) for the specified hue bands, B-Y and R-G axes, and hemispheres of the FM-100 diagram: left (caps 1–43), right (caps 44–85), upper (caps 27–70) and lower (caps71–26). <b>Figure S1</b> – FM-100 scores (ÖTES) for individual post-COVID participants as a function of age. For comparison, plotted are mean ÖTES scores for each age group of normal trichromats27,29,30, as presented in Table 1. Numbers accompanying points correspond to IDs of post-COVID participants, whose values exceed the lowest normal trichromats’ mean. <b>Table S3</b><b> </b>– Spearman's correlation coefficient (<i>р</i>) between √PES in different hue bands and the number of days elapsed after the recovery of post-COVID participants. <b>Figure S2</b><b> </b>–<b> </b>√PES for post-COVID participants in different hemispheres of the FM-100 diagram: (a) √PES in left and right hemispheres; (b) √PES in upper and lower hemispheres; (c) √G–B – √R–Y difference (lower vs. upper hemisphere) as a function of the time elapsed after the participants’ recovery. Zero difference is indicated by a solid horizontal line. Colour-coded are participants’ age groups. <b>Table S4</b><b> </b><b>– </b>The Vingrys and King-Smith indices of moment of inertia. Highlighted are values exceeding the cut-off values for normal trichromats, C-index &gt;1.12 and S-index &gt;1.38, and negative Angles, indicators of a tritan defect. <b>Table S5</b> – Descriptive statistics of FM-100 indices for post-COVID participants (N=5) with negative Angle in comparison with mean values for 72 participants with positive Angle stratified as two groups in accord with the severity C-index cut-off value, C=1.12. <b>Table S6</b> – Clusters of post-COVID participants based on their FM-100 performance, TES and the three parameters of moment of inertia35, obtained using the hierarchical clustering method. In each cluster, participants’ IDs are given in colour, as coded in Figure 6. Highlighted (in grey) are individual participants’ indices that assume an acquired (mild) colour vision deficiency: TES&gt;90th percentile, C-index and S-index exceeding the cut-off values, negative and relatively low positive Angle.

新冠感染后（Post-COVID-19）阶段，已有多项研究记录了各类眼科症状与视觉损伤。我们推测色觉功能亦可能受到累及。本研究采用法恩斯沃思-孟塞尔100色相测试（Farnsworth-Munsell 100 Hue test，FM-100），对77名曾感染新冠病毒的受试者（年龄18~68岁）的色辨别能力进行了评估。

本研究的补充资料可通过以下链接下载：https://figshare.com/s/6900f26033c71afc7888。
<b>数据集</b>：本研究分析所用数据。
<b>附录1</b>：77名新冠康复受试者的FM-100图谱误差分布。
<b>附录2</b>：用于计算D-15、D-15d及FM 100-Hue测试主、副轴的计算机程序。
<b>补充材料表S1</b>：新冠康复受试者的人口统计学特征，以及自我报告的病程时长与症状情况。
<b>表S2</b>：新冠康复受试者的FM-100相关参数：总错误得分（total error score，TES）、四个FM-100模块的错误得分（AES、BES、CES、DES），以及指定色相带、蓝-黄（B-Y）与红-绿（R-G）轴、FM-100图谱各象限的部分错误得分（partial error score，PES）：左侧（色帽1~43）、右侧（色帽44~85）、上方（色帽27~70）与下方（色帽71~26）。
<b>图S1</b>：各新冠康复受试者的FM-100得分（ÖTES）与年龄的相关性。作为对照，同时绘制了文献27、29、30中报道的正常三色视者各年龄组的平均ÖTES得分，与表1中数据一致。数据点旁的编号对应总错误得分高于正常三色视者最低平均值的新冠康复受试者ID。
<b>表S3</b>：新冠康复受试者不同色相带的√PES与康复后经过天数之间的斯皮尔曼相关系数（ρ）。
<b>图S2</b>：新冠康复受试者在FM-100图谱各象限的√PES：(a) 左侧与右侧象限的√PES；(b) 上方与下方象限的√PES；(c) 蓝-绿轴与红-黄轴的√PES差值（下方象限与上方象限的差值）与受试者康复后经过时长的关系。差值为0时以实心水平线标示，受试者年龄组以颜色编码区分。
<b>表S4</b>：Vingrys与King-Smith转动惯量指数。其中标注了超出正常三色视者截断值的结果：C指数>1.12、S指数>1.38，以及负值角度（提示存在蓝色觉缺损）。
<b>表S5</b>：5名角度为负值的新冠康复受试者的FM-100指数描述性统计，并与72名角度为正值的受试者按色觉严重程度以C指数截断值C=1.12分为两组后的均值进行对比。
<b>表S6</b>：基于FM-100表现、总错误得分（TES）及3项转动惯量参数35，通过分层聚类法得到的新冠康复受试者聚类结果。每个聚类中受试者的ID以颜色编码，与图6中的编码一致。其中灰色高亮标注的为符合获得性（轻度）色觉缺损特征的个体：总错误得分（TES）>第90百分位数、C指数与S指数超出截断值、角度为负值或相对较低的正值。