Comparison between Hardy–Rand–Rittler 4th edition and Ishihara color plate tests for detection of dyschromatopsia in optic neuropathy

Background

The aim of this work was to compare the specificity–sensitivity balance of the Hardy–Rand–Rittler (HRR) 4th edition with the Ishihara color plate tests for color-vision defects in patients with optic neuropathy.

Methods

This is a prospective case-control study. The study group included 43 patients (48 eyes) with newly diagnosed optic neuropathy, and the control group included 33 patients (33 right eyes) who were referred to the eye clinic for conditions other than optic nerve or retinal macular disorders. Individuals with visual acuity of less than 20/70 (0.54 Log MAR) were excluded. All patients underwent comprehensive eye examination and color-vision evaluation with both tests in a random order under standardized lighting conditions. The scores of the Ishihara and HRR tests were set as the number of plates identified out of 12 and six respectively.

Results

The receiver operating characteristics (ROC) curve was statistically significantly better when using the HRR test (area under curve [AUC]?=?0.93?±?0.03) than for the Ishihara test (AUC?=?0.77?±?0.05) (P?=?0.0006). The best specificity–sensitivity balance for the HRR was 100 % and 79 % respectively, and for the Ishihara test 100 % and 48 % respectively.

Conclusions

The HRR 4th edition test proved to be superior to the Ishihara test in detecting acquired dyschromatopsia due to optic neuropathy. We recommend using the HRR 4th edition test as a screening method for detection of color-vision defects in patients with optic neuropathy.     

Evaluation of the new web-based "Colour Assessment and Diagnosis" test.

PURPOSE: The purpose of the study was to determine the sensitivity, specificity, and repeatability of the web-based Colour Assessment and Diagnosis (CAD) test in comparison to current tests of color vision. METHODS: Thirty color normals and 30 color deficients, identified and diagnosed by the Nagel anomaloscope, were tested. The results of the CAD test were compared with standard tests like Nagel anomaloscope, Ishihara (concise version, 2001), Hardy, Rand and Rittler (HRR; 4 ed) pseudoisochromatic test, and the Farnsworth Munsell 100 (FM-100) hue test. RESULTS: Using the Nagel anomaloscope as the "gold standard," the sensitivity with the CAD test was 93.33%, Ishihara 96%, HRR 100%, and the FM-100 hue 100%. The specificity was 100% with CAD and the Ishihara color plates, whereas it was 33% with the HRR and 83% with the FM-100 hue test. The concurrent validity of the CAD test for color normals was 93.75%. The concurrent validity of CAD test for color deficiency was 100%. Thus, anyone failing the CAD test has a color defect. The coefficient of agreement for the Nagel anomaloscope and the CAD test was 0.93, with Ishihara it was 0.96, with the HRR it was 0.33, and with FM-100 hue it was 0.83. CONCLUSION: These results showed that the CAD test is a valid test for identifying congenital red-green color deficiency. Further testing is required in a larger population of anomalous trichromats.     

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.     

Identification of red–green colour deficiency: sensitivity of the Ishihara and American Optical Company (Hard,Rand and Rittler) pseudo‐isochromatic plates to identify slight anomalous trichromatism

Screening sensitivity, based on a specific number of errors, of the Ishihara plates and of the American Optical Company (Hardy, Rand and Rittler) plates (HRR plates) was determined by reviewing data obtained for 486 male anomalous trichromats identified and classified with the Nagel anomaloscope. Data were obtained for the 16 screening plates, with Transformation and Vanishing numeral designs, of the 38 plate Ishihara test, and for the four red–green screening plates (with six Vanishing designs) of the HRR test. Sensitivity of the Ishihara plates was found to be 97.7% on 4 errors and 98.4% on 3 errors. Only anomalous trichromats with slight deficiency, according to the anomaloscope matching range, made 8 errors or fewer. One screening error, a single missed figure, is normally allowed as a pass on the HRR test and 3 errors is often recommended as the fail criterion to eliminate false positive results. Twenty‐three subjects made no error on the HRR screening plates and 12 subjects made a single error (35 anomalous trichromats). Screening sensitivity was therefore 92.8% using 2 errors as the fail criterion. Screening sensitivity was reduced to 87% when 3 errors was the fail criterion, and some deuteranomalous trichromats with moderate deficiency, according to the anomaloscope matching range, were not identified. Individuals who make a maximum of 2 errors on the HRR test, or on the Richmond HRR 4th Edition, should be re‐examined with the Ishihara plates to determine their colour vision status. The present review confirms that the Ishihara test is a very sensitive screening test and identifies people with slight anomalous trichromatism. The HRR test is unsatisfactory for screening and should not be chosen solely for this purpose.     

Bilateral Sequential Anterior Ischaemic Optic Neuropathy After Coronary Artery Bypass Surgery

ABSTRACT

A 63 year-old man underwent coronary artery bypass surgery. The day following the surgery he complained of blurred vision in the lower-half of the visual field of his left eye. Two days after the surgery blurred vision also developed in his right eye. Sequential involvement of the eyes and elevation of the erythrocyte sedimentation rate led to consideration of a diagnosis of arteritic anterior ischaemic optic neuropathy. A temporal artery biopsy was performed to rule out giant cell arteritis which was negative and a final diagnosis of non-arteritic anterior ischaemic optic neuropathy was made. This case emphasizes that sequential involvement of the eyes may be seen in patients with non-arteritic anterior ischaemic optic neuropathy associated with non-ocular surgery although simultaneous involvement is more commonly seen in this situation.     

Optic Nerve Head Elastometry in Both Eyes of Patients with Unilateral Non-arteritic Anterior Ischaemic Optic Neuropathy – May It Be a Novel Aspect of the Pathogenesis?

In this prospective study, the biomechanical properties of optic nerve head (ONH) and cornea in both eyes of patients with non-arteritic anterior ischaemic optic neuropathy and healthy control eyes were investigated. ONH elastometry was measured with real-time elastography, and corneal elastometry was measured with ocular response analyser. Elastometry of cornea and ONH was lower in both eyes of patients with unilateral non-arteritic ischaemic optic neuropathy than in healthy control eyes. The role of these biomechanical differences in the pathogenesis of non-arteritic ischaemic optic neuropathy should be investigated further.     

Bilateral Non-arteritic Anterior Ischaemic Optic Neuropathy as the Presentation of Systemic Amyloidosis

A 75-year-old hypertensive female with stable idiopathic intermediate uveitis presented with bilateral sequential optic neuropathy with optic disc swelling. The optic neuropathy in the first affected eye (right) was thought to be due to non-arteritic anterior ischaemic optic neuropathy (NAION). Asymptomatic left optic disc swelling was found at routine review 2 months later, and a diagnosis of giant cell arteritis (GCA) was sought. Temporal artery duplex ultrasound showed the “halo sign,” but a subsequent temporal artery biopsy showed light-chain (AL) amyloidosis with no signs of giant cell arteritis. In this case, bilateral sequential ischaemic optic neuropathy mimicking non-arteritic anterior ischaemic optic neuropathy was the presenting sign of systemic amyloidosis involving the temporal arteries.     

Screening of red-green defects of colour vision with pseudoisochromatic tests.

Fifty red-green defectives and 100 normal subjects were examined with the second edition of the Bostr?m-Kugelberg (BK II, 1972) series and the Ishihara complete edition (1976) of pseudoisochromatic plates. The results are related to those obtained with the first edition of the Bostr?m-Kugelberg test (BK I, 1944) and the Bostr?m test (II B, 1950) and to the classification of defects obtained with the Nagel anomaloscope. The 50 red-green defectives were originally selected by using a combination of the BK I and II B tests. The normal subjects also, passed this preliminary test, as well as an examination with the Nagel anomaloscope. In the final examinations performed under standardized conditions, three red-green defectives passed both the BK II and the BK I test, while eight defectives passed the Ishihara test. Combination of BK II or BK I test with the Ishihara test does not improve the result. Only one defective (a borderline case of protanomaly) passed the separate II B test. Normal subjects were not classified as colour defectives with any of the four pseudoisochromatic tests used. All normal subjects passed both the BK II and the Ishihara test. Classified as suspected red-green defectives (one misreading made in standardized conditions) were five normal subjects with the II B test and one normal subject with the BK I test. In the second edition of Bostr?m-Kugelberg series, the plates numbered 3, 5, 11, 16 and 18 are clearly less effective than respective plates of the first edition. Only the plates numbered 1 and 10 have markedly improved in the second edition. Red-green defectives made on average 0.54 misreadings per plate in the BK II test as compared with respective 0.62 in BK I, 0.69 in the Ishihara and 0.56 in the II B test.     

Bilateral anterior ischaemic optic neuropathy and acute renal failure: a case report

A patient who developed acute renal failure and subsequent bilateral non-arteritic anterior ischaemic optic neuropathy is described, The case was atypical in that the condition affected both eyes simultaneously, occurred in a young patient and was not associated with a recognised cause of renal failure or preexisting condition. Optic atrophy in the form of optic disc cupping, an unusual feature of non-arteritic optic neuropathy, was also present.     

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.     

Velhagen Pflügertrident pseudoisochromatic plates in screening congenital red-green vision defects

Red-green colour vision defects were screened in a group of 425 trade school students using Velhagen Pflügertrident pseudoisochromatic plates. Thereafter, the students were examined with the Nagel anomaloscope. Of the 425 students, 31 (7.3%) were found to be colour defectives. Deuteranomalous defects were found in 4.9% of cases; deuteranopic defects, in 0.2%; and protanomalous defects, in 2.1%. There were no protanopic 1 students in the study group. The Velhagen plates found 19 of the 31 defectives (sensitivity, 61.3%); none of the students with normal colour vision were suspected of being colour defectives (specificity, 100%). The sensitivity of the Velhagen plates is not as high as that of other pseudoisochromatic tests. However, the Velhagen Pflugertrident test is easy to use when screening of preschool-aged children is needed.

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Velhagen Pflügertrident pseudoisochromatic plates in screening congenital red-green vision defects

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This study was supported by Finnish Eye Foundation

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Offprint requests to: M. Mantyjärvi     

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.     

The Ohkuma's test: an evaluation

Ohkuma's pseudoisochromatic test was evaluated in 147 subjects including 130 cases with hereditary dyschromatopsias, and compared with the color vision tests of Ishihara, the HRR, the Farnsworth Panel D-15 and the City University Color Vision Test. Qualitatively, Ohkuma's test was more exact for the diagnosis of the axis of the dyschromatopsia (protan or deutan); quantitatively, Ohkuma's test was of good efficiency for screening, but the quantitative gradation was mediocre, indicating dichromatism in only 3/4 of the cases.     

Abnormal Peripapillary Nerve Fibre Layer Thickness Demonstrated by Optical Coherence Tomography in Cases of Optic Atrophy: Is There a Correlation With Aetiology?

Optical coherence tomography of the peripapillary nerve fibre layer has been used in optic atrophy for identification of axonal loss and for differential diagnosis. In the present study, we aim to evaluate whether the pattern of peripapillary nerve fibre layer thinning, based on the optical coherence tomography normative database, correlates with aetiology in cases of optic atrophy. This retrospective study is approved by the Tan Tock Seng Hospital Ethics Review Board. Consecutive patients with optic atrophy seen in the Neuro-Ophthalmology Clinic between May 2005 and August 2006 were included. The normal eyes of the patients served as controls. All patients underwent imaging using Stratus optical coherence tomography of the peripapillary nerve fibre layer, optic disc photographs and Humphrey perimetry. The aetiology of each case of optic atrophy were made by means other than the optical coherence tomography. Significant nerve fibre layer thinning was defined as a reading in the red quadrant on the Stratus optical coherence tomography printout, which indicates the 1% percentile of the Stratus optical coherence tomography normative database. Twenty-nine patients (39 eyes) with optic atrophy were included in the study. The cases included non-arteritic anterior ischaemic optic neuropathy (14 eyes), compressive optic neuropathy (10 eyes), toxic optic neuropathy, traumatic optic neuropathy, previous optic neuritis, inflammatory optic neuropathy, and central retinal artery occlusion. Cases with isolated superior quadrant thinning were three times more likely to be non-arteritic anterior ischaemic optic neuropathy (odds ratio 4.07; 95% confidence interval: 0.8–20.75), although this was not statistically significant (p?=?0.079). Patients with isolated superior peripapillary nerve fibre layer thinning on the Stratus optical coherence tomography are more likely to be non-arteritic anterior ischaemic optic neuropathy patients. The other aetiologies did not show any specific pattern of thinning.     

Clinical use of the American Optical Company (Hardy, Rand and Rittler) pseudoisochromatic plates for red-green colour deficiency

The efficiency of the American Optical Company (Hardy, Rand and Rittler) (HRR) plates for screening, grading and classifying red-green colour deficiency was examined for 401 mate colour deficient subjects previously identified and diagnosed with the Nagel anomaloscope. There were 83 protanopes, 30 protanomalous trichromats, 96 deuteranopes and 192 deuteranomalous trichromats. Screening sensitivity was found to be 100% for dichromats and 96.4% for anomalous trichromats based on one screening error (35 subjects, including 7 dichromats, were identified by a single error). Thirty subjects (13.5%) made errors on screening plates only and were identified as having minimal colour deficiency. The HRR grading system did not distinguish dichromats and anomalous trichromats; 54% of dichromats were graded as having moderate rather than severe colour deficiency. Protan/deutan classification was correct for 95% of subjects who failed grading plates. HRR grades for anomalous trichromats were compared with the anomaloscope matching range and with pass or fail of the D15 test. The results show that only two rather than four grading categories can be distinguished by the HRR plates and that both the D15 and the HRR plates are needed in a vocational test battery to establish the severity of colour deficiency.     

Using clinical tests of colour vision to predict the ability of colour vision deficient patients to name surface colours

PURPOSE: To determine the predictive power of commonly used tests for abnormal colour vision to identify patients who can or cannot name surface colours without error. METHODS: The colour vision of 99 subjects with colour vision deficiency (CVD) was assessed using the Ishihara, the Richmond HRR (2002), the Farnsworth D15, the Medmont C100 and the Nagel anomaloscope. They named 10 surface colours (red, orange, brown, yellow, green, blue, purple, white, grey and black), which were presented in two shapes (lines and dots) and three sizes. The surface colours were also named by an age-matched group of 20 subjects with normal colour vision. The performance of the clinical tests to predict the CVD subjects who made no colour naming errors and those who made errors is expressed in terms of the predictive value of a pass P((P)) and the predictive value of a fail P((F)). RESULTS: The P((P)) values of the tests were between 0.59 and 0.70 and P((F)) values were between 0.77 and 1.00. CONCLUSIONS: A 'mild' classification with the Richmond HRR test, especially if no more than two errors are made on the HRR diagnostic plates, identifies patients with abnormal colour vision who are able to name surface colour codes without error or only the occasional error. A pass of the Farnsworth D15 test identifies patients who will make no or few (up to 6%) errors with a 10 colour code, but who will be able to name the colours of a seven colour code that does not include orange, brown and purple. If protans are excluded, the predictive value for a pass P((P)) for the Farnsworth D15 is improved from 0.59 to 0.70. The anomaloscope is not an especially good predictor of those who can recognise surface colour codes. However, an anomaloscope range >35 units identifies those who have difficulty in recognising surface colour codes, as does a fail at the Farnsworth D15 test.     

Leber''s optic neuropathy: clinical and visual evoked response studies in asymptomatic and symptomatic members of a 4-generation family.

A clinical and neuro-ophthalmological examination using tests of visual acuity, quantitative visual field analysis, tests of colour discrimination, ophthalmoscopy, and pattern visual evoked responses was performed on 2 symptomatic and 16 asymptomatic members of a family with Leber's optic neuropathy. The visual evoked responses were abnormal in the 2 clinically affected males and in 1 asymptomatic male. Tests of colour discrimination with Ishihara plates, the Farnsworth-Munsell 100 hue test, and the Nagel anomaloscope revealed abnormalities in 8 asymptomatic family members, with the Farnsworth-Munsell test proving to be the most sensitive to mild abnormalities of colour discrimination. The occurrence of detectable neuro-ophthalmological abnormalities within this family is in keeping with the expected pattern of transmission of Leber's optic neuropathy. The significance of detection of presymptomatically affected cases and asymptomatic carriers is discussed.     

Central retinal artery and vein collapse pressure in giant cell arteritis versus nonarteritic anterior ischaemic optic neuropathy

Arteritic anterior ischaemic optic neuropathy and nonarteritic anterior ischaemic optic neuropathy are acute optic neuropathies, which have to be differentiated from each other. It was the purpose of this study to assess whether ophthalmodynamometry with an assessment of the collapse pressure of the central retinal artery (CRA) and vein (CRV) is helpful for that. Using a Goldmann contact lens-associated ophthalmodynamometer, the diastolic collapse pressure of the CRA and CRV were measured in six patients (eight eyes) with giant cell arteritis-induced anterior ischaemic optic neuropathy (GC-AION) and in 10 patients (12 eyes) with acute non-arteritic anterior ischaemic optic neuropathy (NAION). CRA collapse pressure was significantly (P=0.001; 95% confidence interval (CI): -68.7, -20.0) lower in the GC-AION group (52.7+/-24.6 arbitrary units) than in the NAION group (97.0+/-25.8 arbitrary units). CRV collapse pressure did not vary significantly (P=0.47). As measured by ophthalmodynamometry, CRA pressure is significantly lower in GC-AION than in NAION. CRV pressure does not vary markedly. These finding may be helpful for the clinical differentiation between GC-AION and NAION, and may give hints for the pathogenesis.     

Visual Loss Due to Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) Immediately Following Routine Strabismus Surgery Under General Anesthesia-A Case Report

Purpose: To report a case of non-arteritic anterior ischemic optic neuropathy (NAION) observed immediately after uncomplicated strabismus surgery performed under general anesthesia. Methods: A 61-year-old woman underwent an uncomplicated strabismus surgery of her right eye under general anesthesia. Preoperatively visual acuity (VA) was LogMAR 0.18 in both eyes. Design: Retrospective, observational case report and literature review. Results: Two days following surgery, patient presented with painless visual loss. VA was No Perception of Light (NPL). Fundoscopy revealed right optic disc swelling and relative afferent pupillary defect. Perioperatively patient experienced 2 hypotensive episodes. She was evaluated for alternative etiologies of her optic neuropathy, with negative results. She was found to have mild hypercholesterolemia, which was not known prior to surgery. After 2 months she developed optic atrophy in the affected eye and the visual acuity did not recover. Conclusions: To our knowledge, this is the first documented case of non-arteritic anterior ischemic optic neuropathy occurring immediately after strabismus surgery.     

Ischaemic Optic Neuropathy in Lyme Disease

A 57-year-old man was referred for a painful acute inferior visual field defect in his right eye. Fundus examination of the right eye revealed diffuse optic disc oedema compatible with a papillitis. Cerebrospinal fluid (CSF) findings were consistent with lymphocytic meningitis, and serologic tests for Lyme disease were positive in both serum and CSF. After treatment with ceftriaxone and bolus of methylprednisolone, right eye inferior altitudinal visual field defect persisted despite resolution of papillitis, and fundus examination disclosed a superior optic atrophy in the right eye. To our knowledge, it is the first reported case of a unilateral Lyme optic neuritis occurring simultaneously to neuroborreliosis and further complicated by non-arteritic anterior ischaemic optic neuropathy.