TL型色觉检查仪矫正红绿色盲的作用

1992年6月～8月，我们对内蒙古乌海市机动车驾驶员作了职业健康体检。现将2070名机动车驾驶员的色觉检查反复查结果分析如下。调查对象：本次体检为2070名机动车驾驶员，全部为男性。年龄最小18岁，最大59岁。驾驶工龄1～40年。材料与方法：（1）图谱法：采用俞自萍他盲检查图》在明亮自然光下，距离to－80cm，根据驾驶员的文化程度，让其辨认《色盲检查图》中的阿拉伯数字和图案，每图阅读时间不得超过10秒。（2）仪器法：选用铁道部劳动卫生研究所与北京市文教用品二厂联合研制的初型色觉检查仪。在散射光下受试者坐在距仪器sin处，调整仪…     

色觉矫正眼镜的临床试用

色盲是比较常见的遗传性眼病,对许多职业有严重影响。根据大组家系调查,约12万例的群体患病率为3％,基因频率为0．051,男性患病率为5．1％,女性为0.8％[1]。我们使用北京天中公司研制的“色觉矫正眼镜’进行了临床试用,报告如下：临床资料：门诊体检中查出红绿色弱及色盲80例,其中男79例,占98.7％,女1例,占1．3％,年龄为16岁～53岁,平均为36岁,有家庭史20例,职业分布有司机、干部、工人、学生等。红绿色弱7例,次重级（Ⅱ）红绿色盲21例,重级（Ⅰ）红绿色盲52例。方法：（1）色觉障碍的诊断、分型、级别和效果判断均采用俞自…     

伊朗女中学生色觉缺失的患病率(英文)

色盲是常见病,先天性色盲X连锁隐性遗传。我们的研究中,随机分组抽样1600个女学生,进行Ishihara假同色表检查。其中0.63%色觉缺失,其中6例绿色弱(0.38%),4例红色弱(0.25%)。     

色觉矫正眼镜的临床试用

本文报道用色觉矫正眼镜矫正各类型觉异常的效果，所有８７例戴镜后辨色力均有不同程度的提高，其中红绿色弱，次重级红绿色盲的显效率为１００％，重级红绿色盲为６２．５％，就目前尚无有效疗法的先天性色觉异常而言，配戴色觉矫正眼镜矫正色盲是有价值的。     

高度近视伴色觉缺失的家系分析

目的:评估高度近视伴色觉缺失患者的遗传学特征和临床表现方法:就同一家族4代42个成员中有8位患者给予了详细的眼科检查,Ishihara盘和FM100H试验检测患者有无红绿色觉缺失,全视野视网膜电图评价其视网膜功能.结果:患者8位均因高度近视视力下降,其中6例有红绿色觉缺失,眼底检查显示以弥漫性视网膜脉络膜萎缩为特征的近视改变.2例患者ERG检查出现视杆细胞的暗适应异常和视锥细胞的反应消失,根据家系,红绿色觉缺失属X连锁的隐性遗传.结论:在这个家族成员中,同时发生的高度近视和色觉缺失可能有共同的遗传学基础.     

国产色觉检查D—15色彩排列试验盒的临床应用

本文应用国产色觉检查Ｄ－１５色彩排列试验盒和国外ＰａｎｅｌＤ－１５试验盒对２５例（５０眼）正常人，１４１例（２６３眼）先天性色觉异常者和眼病病人进行检查，证实国产色觉检查Ｄ－１５色彩排列试验盒已达到国外ＰａｎｅｌＤ－１５试验盒的水平，可供临床应用。     

色盲隐形眼镜矫正色觉障碍的临床研究

目的 :观察研究色盲隐形眼镜矫正色觉障碍患者的辨色能力。方法 :用色盲检查图谱 ,在自然或日光灯下 ,检查佩戴色盲隐形眼镜前后的辨读正确率进行统计分析 ,观察矫正效果。结果 :3 6例患者除了 2例无效外 ,3 4例有效 ,有效率占 90 % ,平均提高识别率 2 4 48%± 10 63 %。结论 :色盲隐形眼镜矫正色觉障碍中的红、绿色盲和色弱患者是有效、安全的 ,而且与患者的严重程度有关 ,色盲越严重 ,提高识别率就越高。     

同一家庭3个姐妹色觉障碍

目的:评价我校医学生和她的家庭成员先天色觉障碍的遗传特征,以建立其遗传模式.方法:运用Ishihara(石原)假同色图试验测定色觉障碍,用FW100色调试验评估其类型.并进行眼科检查和遗传学研究,建立色盲家谱,并对她的家庭给予遗传学咨询.结果:眼科检测结果显示双眼最佳矫正视力为20/20(1.0),近视矫正屈光度-2D,裂隙灯检测和眼压测量结果在正常范围,眼底镜检查视神经、黄斑和周边视网膜均正常,其它外眼评估和神经学检测正常,先证者的姐妹和她父母的眼科检测也正常,3姐妹和父亲的IPPT试验错误得分为19～20/25,结果和红绿色盲中绿色觉异常者一致.染色体分析和卵巢周期均正常.结论:根据她家谱,她的色盲是伴X染色体的隐性外显率模式的遗传特征.     

The new Richmond HRR pseudoisochromatic test for colour vision is better than the Ishihara test

Aim: The Hardy‐Rand‐Rittler (HRR) pseudoisochromatic test for colour vision is highly regarded but has long been out of print. Richmond Products produced a new edition in 2002 that has been re‐engineered to rectify shortcomings of the original test. This study is a validation trial of the new test using a larger sample and different criteria of evaluation from those of the previously reported validation study. Methods: The Richmond HRR test was given to 100 consecutively presenting patients with abnormal colour vision and 50 patients with normal colour vision. Colour vision was diagnosed using the Ishihara test, the Farnsworth D15 test, the Medmont C‐100 test and the Type 1 Nagel anomaloscope. Results: The Richmond HRR test has a sensitivity of 1.00 and a specificity of 0.975 when the criterion for failing is two or more errors with the screening plates. Sensitivity and specificity become 0.98 and 1.0, respectively, when the fail criterion is three or more errors. Those with red‐green colour vision deficiency were correctly classified as protan or deutan on 86 per cent of occasions, with 11 per cent unclassified and three per cent incorrectly classified. All those graded as having a ‘mild’ defect by the Richmond HRR test passed the Farnsworth D15 test and had an anomaloscope range of 30 or less. Not all dichromats were classified as ‘strong’, which was one of the goals of the re‐engineering and those graded as ‘medium’ and ‘strong’ included dichromats and those who have a mild colour vision deficiency based on the results of the Farnsworth D15 test and the anomaloscope range. Conclusions: The test is as good as the Ishihara test for detection of the red‐green colour vision deficiencies but unlike the Ishihara, also has plates for the detection of the tritan defects. Its classification of protans and deutans is useful but the Medmont C‐100 test is better. Those graded as ‘mild’ by the Richmond HRR test can be regarded as having a mild colour vision defect but a ‘medium’ or ‘strong’ grading needs to be interpreted in conjunction with other tests such as the Farnsworth D15 and the anomaloscope. The Richmond HRR test could be the test of choice for clinicians who wish to use a single test for colour vision.     

Colorimetric evaluation of iPhone apps for colour vision tests based on the Ishihara test

Given the versatility of smart phone displays, it was inevitable that applications (apps) providing colour vision testing would appear as an option. In this study, the colorimetric characteristics of five available iPhone apps for colour vision testing are assessed as a prequel to possible clinical evaluation. The colours of the displays produced by the apps are assessed with reference to the colours of a printed Ishihara test. The visual task is assessed on the basis of the colour differences and the alignment to the dichromatic confusion lines. The apps vary in quality and while some are colorimetrically acceptable, there are also some problems with their construction in making them a clinically useful app rather than curiosity driven self‐testing. There is no reason why, in principle, a suitable test cannot be designed for smart phones.     

Detection of functional vision loss using the Ishihara plates

Many techniques have been described for the detection of functional visual loss. We report four cases in which Ishihara pseudo-isochromatic colour plates gave objective evidence of functional vision loss. In all cases the patients were able to read the first test pattern (No. 12), but could not distinguish any of the following pseudo-isochromatic numbers (plates 2–17). However, they experienced no difficulty in tracing the winding lines (plates 18–24), demonstrating that they in fact had normal colour vision.     

Comparison of Ishihara and Hardy-Rand-Rittler Pseudoisochromatic Plates in Non-Arteritic Anterior Ischaemic Optic Neuropathy

Pseudoisochromatic plates, such as Ishihara and Hardy-Rand-Rittler (HRR) tests, are designed as screening tools to test colour vision defects. The tests are often designed to detect congenital red-green colour blindness and their measurement properties for acquired optic neuropathies are not known. The aim of this study is to determine the sensitivity and specificity of Ishihara and HRR pseudoisochromatic plates in detecting dyschromatopsia in patients with unilateral non-arteritic anterior ischaemic optic neuropathy. Nineteen such patients were tested using Ishihara and the HRR plates in the affected and the unaffected (control) eye. The results were correlated to that on an anomaloscope (Oculus HMC Anomaloskop MR^®). Mild deuteranomaly was the dyschromatopsia detected by an anomaloscope in the affected eye of the patients. The sensitivity and specificity of the Ishihara test in the affected eyes are 75% and 40%, respectively. The sensitivity and specificity of the HRR test in eyes affected with non-arteritic anterior ischaemic optic neuropathy are 100% and 20%, respectively. It is concluded that the anomaloscope that was considered the “gold standard” has several limitations and may not detect all acquired dyschromatopia. On the other hand, whilst it is correct that pseudoisochromatic plates are screening tests and the results must be correlated with other optic nerve functions, the HRR test has a higher sensitivity and specificity than Ishihara colour plates in detecting dyschromatopsia in non-arteritic anterior ischaemic optic neuropathy eyes.     

Errors reading the Ishihara pseudoisochromatic plates made by observers with normal colour vision

Background: Ishihara pseudoisochromatic plates are one of the best screening tools for red‐green colour vision deficiencies. Although a majority of persons with normal colour vision read all plates correctly, a significant proportion makes mistakes. The purpose of this study was to obtain results for normal trichromats reading the Ishihara plates and analyse the misreading responses to seek clinical implications. Methods: A sample of 249 (161 female) was tested with the Ishihara pseudoisochromatic plates. The number and nature of errors were recorded and typical errors, those that observers with abnormal colour vision were expected to make, were distinguished from other kinds of error. Results: Out of 249 normal trichromats, 111 individuals (45 per cent) misread at least one plate. Females made up to six total errors and males up to five total errors. When only typical errors were counted, all the normal trichromats made two or fewer errors. There was no significant gender difference for either total or typical errors. Conclusion: It is suggested that clinicians count only typical errors when administering the Ishihara test. Using a criterion of no more than two typical errors for a diagnosis of normal colour vision could improve the specificity and sensitivity of the test.     

Chromaticity co‐ordinates of Ishihara plates reveal that hidden digit plates can be read by S‐cones

Background: The Ishihara pseudoisochromatic plates constitute one of the most commonly used screening tools for red‐green colour vision deficiencies. Even though hidden digit plates are supposed to be read only by those who are colour vision defective, studies report that some normal trichromats can indeed read these plates. By measuring the chromaticity co‐ordinates of the dots used in Ishihara plates, the purpose of this study was to clarify the mechanism that enables normal trichromats and colour vision defectives to read the plates, particularly hidden digit plates. Methods: Spectrophotometric measurements were made for a 24‐plate version of the Ishihara pseudoisochromatic plates and chromaticity co‐ordinates of the dots were expressed in the MacLeod‐Boynton diagram. Results: As theoretically expected, reading of Ishihara plates by normal trichromats was mediated by the dot chromaticity differences along the L/(L + M) axis. On the other hand, reading by colour vision defective observers was made possible mainly by the dot chromaticity differences along the S/(L + M) axis. This would also explain why some normal trichromats can read hidden digit plates, the plates that are supposed to be read only by colour vision defective observers. Conclusion: Normal trichromats read Ishihara plates using their chromatic discrimination ability along the L/(L + M) axis. Red‐green colour vision defective observers rely on S‐cones in reading the plates. Some normal trichromats can read the hidden digit plates because they can extract S‐cone differences efficiently despite the distraction from the L/(L + M) axis.     

[In Press] Development of new test to diagnose color vision disturbance

AIM: To develop a new test for the diagnosis of color vision deficiency. METHODS: Cross-sectional study with 203 subjects (121 females and 82 males) who performed detection tests of color vision disturbance using Ishihara''s original test images and the images created for the new test in print and electronic version. Images of the new test were created in computer with a tool to control the three colors, which formed the central number, and the seven colors, that compose the background of the image. RESULTS: Eight males demonstrated color vision deficiency (prevalence of 3.94% in the total sample and 9.75% in the male sample). There were no identified dyschromatopsia carriers in females. The comparative analysis between the images of the original Ishihara test with the new test (eletronic version and printed) demonstrated, in both cases, a high correlation (96%) between the results of the tests. Although the high correlation between the results, the cutoff point for defining the existence of color vision deficiency was higher than the original Ishihara test, to obtain 100% sensitivity and 100% specificity. CONCLUSION: The new developed test is able to identify subjects with dyschromatopsia similar to the original Ishihara test. The test will also provide an option to create images with geometric elements or simple figures for the test in children.     

Technical Note: The effect of refractive blur on colour vision evaluated using the Cambridge Colour Test, the Ishihara Pseudoisochromatic Plates and the Farnsworth Munsell 100 Hue Test

The results of a prospective study examining the effect of refractive blur on colour vision performance in normal subjects measured with three different colour vision tests are reported. The Farnsworth Munsell 100 Hue (FM100) and Cambridge Colour Test (CCT) results were significantly affected at +6 D of spherical refractive blur, whereas those from the Ishihara Pseudoisochromatic Plate (IPP) test were not. In a clinical setting, correction of refractive error up to 3 D for colour vision testing with these tests may not be required. Poor colour vision should not be attributed solely to refractive causes of poor visual acuity (Snellen equivalent: >6/36). Fastest test times were achieved using IPP, followed by CCT.     

Clinically relevant colour album test for the colour defective medical student

Purpose:To evaluate the impact of color vision deficiency (CVD) in medical undergraduates by a more clinically applicable test.Methods:Cross-sectional study of 31 students with CVD (Ishihara diagnosed) asked to identify subject-specific signs/tests requiring color identification on a customized medical multispecialty designed color album test (CAT). They were further subjected to Farnsworth D-15 testing.Results:The error score of CVD students (4 ± 3.2) on 39 plates of color album test was highly significant as compared to the error score of color normal (0.3 ± 0.6). The CAT depicted linear correlation with Farnsworth D-15 and emerged as a valid tool of assessment. Ishihara interpretation did not correlate with the clinical impact of CVD. Nature of error suggests that CVD students can anticipate problems in dermatology, pathology, hematology, microbiology, and biochemistry.Conclusion:Color album test is a more clinically relevant test for CVD doctors to identify specialties where they can anticipate difficulties     

一种新的计算机适应色觉试验

目的:提出一种新的计算机适应色觉试验(NCACVT)并且解释它在实际应用中的可靠性和重要性.方法:法一孟二式100色度试验(FM100HT)和Holmgren试验已经被改良并且适应计算机应用.经典的Ishihara假同色法试验方法(IPPT)已被假定是色盲的一个简便的筛选检查工具;因此依照Ishihara试验结果,受试者被分为色觉有缺陷组(第1组)和对照组(第2组).第1组为色觉有缺陷者13例(男12例,女1例),年龄在19～29(平均21)岁,而第2组为对照组,13个受试者色觉无缺陷(男8例,女5例),年龄在19～28(平均22)岁.为了研究两组人的色觉敏感性,所有的受试者都要进行FM100HT和NCACVT试验.将经典的IPPT,FM100HT和NCACVT的试验结果用统计学方法进行比较.在这两组中NCACVT和FM100HT的误差计分用秩和检验来分析.结果:在误差计分中的差别分别在统计学上是有显著意义的(U=169,P＜0.05;U=153 P＜0.05).根据NCACVT来诊断色觉缺陷的临界点是通过使用接受机器作特征曲线(ROC)而被发现是23.根据23这个临界点的误差计分,在筛选检查色觉缺陷方面,发现NCACVT具有100%的敏感性和100%的特异性.结论:根据Harper和Reeves,这些特点使得这个试验成为一个可靠的、有创意的眼科实践筛选试验.