计算机控制的Ishihara色觉测试法

目的:研究经计算机控制的Ishihara测试法诊断色盲的可靠性及其与经典Ishihara测试法的一致性,计算机控制的Ishihara测试法的敏感性与特异性;并探讨该测试方法在检测先天性色盲或色弱中的潜在价值。方法:用两种方法测试104名大学生的色觉,年龄20～23岁(中位数21岁)。分别采用经计算机控制的Ishihara色板和经典的Ishihara打印色板显露法对个体色觉进行检查。通过上述两种不同的方法评价每个学生对颜色的感知能力,借此探讨计算机控制的Ishihara测试法的特异性,准确性以及与经典法的一致性。结果:本实验共检测到6位男性色盲患者和1位女性色盲患者。调查该女性学生的家族史,发现其母亲为色盲基因携带者,而其父亲为色盲患者。本实验中男性色盲患病率为13.6%(6/44),女性为1.7%(1/60);整个人群总的患病率为6.7%(7/104)。进行本试验前,这些学生并未意识到自己存在色觉功能缺陷。为探讨这两种方法的一致性,分别对色觉正常和患色盲的学生的测试结果进行比较。结果表明:两种实验方法的特异性及敏感性均为100%,一致性达到100%。结论:计算机控制的Ishihara测试法是数字调控性的,但有关色觉测试的基本概念没有改变。该法总的测试时间和误差计分都已标准化,与手动测试法相比有明显的优势;而且该法与被认为是"金标准"的经典测试法的一致性达到100%。这些特征表明,计算机控制的Ishihara测试法是一种新颖和可靠的方法。     

Red-green colour blindness in Singaporean children

Purpose:  X-linked red-green colour blindness is the most common form of colour blindness. Various studies suggest that, worldwide, 2–8% of men are afflicted with this condition. The purpose of this study is to determine the prevalence of red-green colour blindness in Singaporean schoolchildren.
Method:  A total of 1249 children aged 13–15 years were screened using the Ishihara 24-plate edition book during the School Cohort study of the Risk factors for Myopia visit.
Results:  A total of 1210 children (96.8%) managed to correctly identify at least 13 of the initial 15 plates and were deemed to have normal colour vision. Thirty-three children (32 boys, one girl) were only able to identify nine or less plates and were considered to be colour blind. Overall, 5.4% (95% confidence interval 3%, 7%) of Chinese, 4.9% (1%, 9%) of Malay and 4.9% (2%, 11%) of Indian boys were colour blind ( P  = 0.97). Classification plates 16–17 were useful in determining deutran or protan tendencies in only 14 (43%) of the 33 children identified as being colour blind.
Conclusion:  5.3% of boys and 0.2% of girls were found to be colour blind in this Singapore-based study. Although the Ishihara test proved useful in identifying colour-blind children, other tests are required to accurately classify the types of red-green colour blindness in these children.     

Survey of the accuracy of new pseudoisochromatic plates

The accuracy of three new pseudoisochrometic tests for detecting red–green colour deficiency was assessed. These were the Ishihara plates, the Ishihara test for 'unlettered persons' and Ohkuma's lest cards. We examined 500 subjects; 471 normal trichromats and 29 colour-deficient people, Results obtained for the 1989 edition of the Ishiliara places were compared with the 9th edition and the most efficient plates identified. Although normal trichromats may be expected to make several interpretive misreadings, the Ishihara plates were found to be superior to the 9th edition and to the Ohkuma test (1986) for colour vision screening. The new symbol designs of the Ishihara plates for 'unlettered persons' (1990) were found to be very effective for colour vision screening, and a further study with young children is proposed. The 38 plate I9S9 edition of the Ishihara les; is recommended for use in clinical practice. The designs included in the concise 24 plate edition and the new abbreviated 14 plate edition are not selected from the point of view of accuracy and more reliable results are obtained if the full lest is given or if the practitioner shows only the most efficient designs.     

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.     

Pingelapese achromatopsia: correlation between paradoxical pupillary response and clinical features

AIM: To evaluate the paradoxical pupillary constriction in darkness in patients with Pingelapese achromatopsia (PA), and to describe a connection between this phenomenon and the clinical features. METHODS: 27 patients with PA were examined. All underwent a full ophthalmic examination which included Snellen visual acuity and ophthalmoscopy. Colour vision examination was performed with Ishihara pseudoisochromatic plates and also with a colour plate consisting of five basic colours (red, green, purple, yellow, and orange). Paradoxical pupillary response was examined and documented with a special infrared video camera. Pupils' images were analysed using the Scion Image program and the ratio of pupil size in darkness to its size in light was calculated and recorded. RESULTS: Mean visual acuity was 20/400 (range 20/80-20/800). Colour vision examination showed a mean of 3.2 (SD 1.5) (range 1-5) of Ishihara colour plates, and 0.5 (0.75) (0-3) of basic colour plates. 23 patients (85%) had paradoxical pupillary constriction in darkness. Mean dark/light ratio of pupillary area was 0.86 (range 0.5-1.6). In patients with marked paradoxical pupillary constriction there was a significant correlation of visual acuity and Ishihara score. CONCLUSIONS: Clinical manifestations of achromatopsia include total colour blindness, low visual acuity (mean of 20/400), horizontal pendular or rotatory nystagmus, and photophobia. Most patients have paradoxical pupillary constriction in darkness. When this response is brisk it seems to correlate with lower visual acuity and lower Ishihara score.     

Acquired colour vision deficiency in patients receiving digoxin maintenance therapy

BACKGROUND/AIMS: Disturbances of colour vision are a frequently reported sign of digoxin toxicity. The aim of this study was to investigate the incidence of acquired colour vision deficiency in elderly hospitalised patients receiving maintenance digoxin therapy. METHODS: 30 patients (mean age 81.3 (SD 6.1) years) receiving digoxin were tested using a battery of colour vision tests (Ishihara, AO Hardy Rand Rittler plates, City tritan test, Lanthony tritan album, and the Farnsworth D15). These were compared to an age matched control group. Serum digoxin concentrations were determined from venous blood samples. RESULTS: Slight to moderate red-green impairment was found in approximately 20-30% of patients taking digitalis, and approximately 20% showed a severe tritan deficiency. There was no correlation between colour vision impairment and serum digoxin level. CONCLUSIONS: Formal colour vision testing of elderly patients taking digitalis showed a high incidence of colour deficiency, suggesting that impairment of retinal function can occur even at therapeutic drug levels. As a result, colour vision testing in this population would have limited value for the detection of drug toxicity.     

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.     

Prevalence of colour blindness in young Jordanians

Colour blindness is one of the common genetic disorders observed in all human populations. It is a sex-linked recessive trait. The genes are located on the X chromosome within the Xq28 band. 1,418 university students (1,200 female and 218 male) from Zarka Private University and the Hashemite University were randomly selected and tested for congenital red/green colour blindness, by using Ishihara pseudo-isochromatic colour plates. A total of 23 individuals were found to be colour blind. In females, 4 students (0.33%) were colour blind: 1 of them showed protanomalia, 1 protanopia and 2 deuteranomalia. In males, 19 students (8.72%) were colour blind: 4 showed protanomalia, 3 protanopia, 8 deuteranomalia and 4 deuteranopia. The allelic frequencies of the colour vision gene were found to be 0.087 in males, 0.003 in females and 0.016 in the total population. Studies on colour blindness in Jordan are very few; this population-based investigation is meant to fill a gap in this field.     

Is screening for congenital colour vision deficiency in school students worthwhile? A review a

This review analyses the literature on screening for congenital colour vision deficiency in school students, which predominantly uses the Ishihara test. The review was framed with respect to the established Wilson and Jungner criteria for screening programs. These criteria relate to the characteristics of the condition concerned, the performance of the screening test, the existence of treatment options and the performance of screening programs. The literature reviewed suggests that congenital colour vision deficiency has not been shown to increase risk of road traffic crashes and is not a preclusion to driver licensing in most developed countries. The occurrence of congenital colour vision deficiency has been used to limit entry into certain occupations; however, the value of screening school students with regard to occupational preclusion is questionable. Stronger evidence exists indicating no association between congenital colour vision deficiency and level of educational achievement. Studies showing any association between congenital colour vision deficiency and other health and lifestyle impacts were rare. The most commonly used screening test (using Ishihara pseudoisochromatic plates) performs well with respect to detecting red‐green colour vision deficiencies. Finally, the only interventions we identified for congenital colour vision deficiency were management ones around the availability of specific tinted lenses and computer programs to aid colour perception in certain tasks. Given this picture, the weight of evidence appears to be in favour of not adopting (or discontinuing) routine colour vision screening programs for school students; however, it may be worthwhile for a career advisor to refer school students to an optometrist or ophthalmologist for colour vision screening, upon expression of interest in an occupation where normal colour vision is either particularly desirable or is a regulatory requirement.     

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.     

Screening for congenital colour vision defects

A prospective comparison between the Ohkuma¹ and Ishihara² pseudoisochromatic (PIC) plates was carried out in a group of 400 patients attending a general ophthalmology practice. The sensitivity of the Ohkuma test was compared to the Ishihara test, and the specificity of both was determined by reference to anomaloscopy as a gold standard.
Both tests correctly identified the same group of 24 patients as having a red/green confusion axis, and the Ohkuma test was equally as sensitive as the Ishihara. The grading plates in both tests are unreliable, but the Ohkuma test is quicker, easier to administer, gives less ambiguous responses and has a clearer cut-off score for abnormality. On the basis of this experience the Ohkuma test is recommended as more appropriate for routine colour vision screening than either the 24 or 38 plate Ishihara tests.     

Colour vision screening in children: an evaluation of three pseudoisochromatic tests

We examined 513 children (258 boys and 255 girls), between 3 and It years of age, with three pseudoisochromatic tests which involve different visual tasks. These were a selection of numeral designs from the Ishihara test, the Ishihara test for Unlettered Persons and the Velhagen Pflügertrident test. Eighteen children were found to be colour deficient. The symbol designs of the Unlettered Persons test were found lo be the quickest and most effective method for examining children under 7 years of age. After 7 years of age the symbol designs of the Unlettered lest and the numeral designs of Ishihara lest were equally effective. The preferred numeral designs for screening children with the Ishihara plates are listed. Verbal identification always produced the most accurate results, Drawing over the figures or selecting replicas increased the viewing lime and assisted children with normal colour vision lo see both figures in transformation designs, especially pathway designs. The Velhagen Pflügertrident test was found to be unreliable for colour vision screening and younger children had difficulty performing the figure matching task.     

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.     

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.     

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%)。     

Efficiency of the Ishihara test for identifying red-green colour deficiency

The Ishihara test is the most widely used screening test for red-green colour deficiency. Results obtained by 401 people with red-green colour deficiency show that the combined sensitivity of the Transformation and Vanishing plates of the 38 plate Edition of the Ishihara plates is 95.5% on eight errors, 97.5% on six errors and 99.0% on three errors. The Hidden digit designs only identified approximately 50% of colour-deficient subjects. The protan/deutan classification plates were found to be more effective for deutans than for protans. No classification was obtained for 18% of protanopes and 3% of deuteranopes who saw neither figure on classification plates; 40% of protanomalous trichromats and 37.5% of deuteranomalous trichromats saw both classification figures and were classified on the relative luminance (clarity) of these figures. The specificity of the Ishihara test was determined in a previous study (Birch and McKeever, 1993) and the results combined with the present data to obtain the overall efficiency of the Ishihara plates for a representative cross section of colour-deficient subjects.     

Jan Lovie‐Kitchin

Background: Colour vision deficiency (CVD) has a high prevalence and is often a handicap in everyday life. Those who have CVD will be better able to adapt and make more informed career choices, if they know about their deficiency. The fact that from 20 to 30 per cent of adults with abnormal colour vision do not know they have CVD suggests that colour vision is not tested as often as it should be. This may be because of practitioner uncertainty about which tests to use, how to interpret them and the advice that should be given to patients on the basis of the results. The purpose of this paper is to recommend tests for primary care assessment of colour vision and provide guidance on the advice that can be given to patients with CVD. Methods: The literature on colour vision tests and the relationship between the results of the tests and performance at practical colour tasks was reviewed. Results: The colour vision tests that are most suitable for primary care clinical practice are the Ishihara test, the Richmond HRR 4th edition 2002 test, the Medmont C‐100 test and the Farnsworth D15 test. These tests are quick to administer, give clear results and are easy to interpret. Tables are provided summarising how these tests should be interpreted, the advice that can be given to CVD patients on basis of the test results, and the occupations in which CVD is a handicap. Conclusion: Optometrists should test the colour vision of all new patients with the Ishihara and Richmond HRR (2002) tests. Those shown to have CVD should be assessed with the Medmont C‐100 test and the Farnsworth D15 test and given appropriate advice based on the test results.     

Visual function after optic neuritis: a preliminary study

We assessed visual function after recovery from optic neuritis in 15 consecutive patients using five objective tests: colour vision testing with Ishihara colour plates and with D15 colour desaturated spots, Humphrey automated perimetry, contrast acuity testing with Regan letter charts and testing of visual evoked response (VER). Recovery of visual function was not found to be dependent on presenting Snellen visual acuity or treatment with oral steroids. The most sensitive measures of residual visual deficit were mean defect on automated perimetry, low-contrast acuity and VER.     

The effect of decreased visual acuity on clinical color vision testing

PURPOSE: Evaluate the effect of visual acuity on color vision testing. DESIGN: University based clinical experimental study. METHODS: Right eyes of 12 healthy subjects were fogged with plus lenses to logMAR 1.88 and assessed with D-15 panel, Ishihara, and Hardy-Rand-Rittler (HRR) plates. Subjects were tested at lesser degrees of fogging, 0.1 logMAR intervals. The acuity at which 5% of the population tests abnormally was estimated as follows. The average acuity at which a 10% reduction in correct responses occurred was determined. From this, two standard deviations were subtracted. Examination devices were compared using repeated measures analysis of variance. RESULTS: Color vision testing did not significantly differ from baseline up to logMAR 1.40 (D-15 panel), 1.10 (HRR plates), and 0.72 (Ishihara plates). Testing devices were significantly different (P < .005). CONCLUSIONS: Color vision testing is accurate up to logMAR 1.40 (20/501) with D-15 panel, 1.10 (20/252) with HRR plates, and 0.72 (20/106) with Ishihara plates.     

A new sieve-test for testing colour vision (author's transl)]

From our results we can be sure that the colour test disk is at least as reliable for mass testing for colour blindness as the Ishihara isochromatic colour plates. In practice the test disk has the advantage of constancy of testing conditions and easy and quick procedure. If it is necessary to differentiate between protopia and deuteropia the colour test disk is significantly better Ishihara's colour plates.