The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform
Jennifer Birch - One of the best experts on this subject based on the ideXlab platform.
-
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
Ophthalmic and Physiological Optics, 2010Co-Authors: Jennifer BirchAbstract: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.
-
efficiency of the Ishihara Test for identifying red green colour deficiency
Ophthalmic and Physiological Optics, 1997Co-Authors: Jennifer BirchAbstract: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.
Malcolm B Dick - One of the best experts on this subject based on the ideXlab platform.
-
Ishihara Test performance and dementia
Journal of the Neurological Sciences, 1996Co-Authors: Richard Mccleary, Rodman W Shankle, Ruth A Mulnard, Malcolm B DickAbstract:Ishihara trail-tracing (TT) and number-naming (NN) Tests were administered to a clinical sample of 378 demented patients. Error counts on TT and NN Tests were best fit by a negative binomial (overdispersed Poisson) distribution. TT, NN, and combined (TT + NN) error counts were regressed on patient characteristics (sex, age, and education), severity of cognitive impairment (Mini-Mental State Exam: MMSE), dementia stage (Clinical Dementia Rating: CDR), etiology, onset age, and symptom duration in a negative binomial generalized linear model. Patient characteristics, onset age, and symptom duration had no significant effects on any error count. The effects of MMSE, CDR, and etiology, on the other hand, were highly significant and appear to help discriminate vascular dementia from Alzheimer's disease. MMSE (which taps cognitive skills) correlated with both TT and NN errors. CDR (which taps both cognitive and functional skills) correlated only with TT errors and dementia etiology correlated only with NN errors. These distinct correlational patterns reflect differences between the TT and NN tasks (i.e., trail-tracing vs. number-naming) related to specific brain loci and associated functions. This aspect of the phenomenon suggests that Ishihara Tests have useful clinical applications in dementia.
Andrew G. Lee - One of the best experts on this subject based on the ideXlab platform.
-
Ishihara color plates as a Test for simultanagnosia
American Journal of Ophthalmology, 1998Co-Authors: Paul W. Brazis, Andrew G. Lee, Nancy J. Newman, N GraffradfordAbstract:Abstract PURPOSE: To alert ophthalmologists to the use of Ishihara color plates in the detection of simultanagnosia. METHODS: We examined seven patients referred for impaired vision. Evaluation included color plate Testing with Ishihara color plates. RESULTS: All seven patients had simultanagnosia, with marked difficulty in identifying the numbers in Ishihara color plates despite adequate visual acuity and the ability to name all of the colors in the plates correctly. One of these patients was referred with the diagnosis of a cone dystrophy because of her poor performance on the Ishihara Test. All of the patients had bilateral occipitoparietal damage or atrophy on magnetic resonance imaging. CONCLUSIONS: Ophthalmologists must be aware that a poor performance with Ishihara plates may not be attributable to an impairment of color vision but rather to occipitoparietal brain damage associated with simultanagnosia.
Maria Frucci - One of the best experts on this subject based on the ideXlab platform.
-
Wearable Improved Vision System for Color Vision Deficiency Correction
IEEE journal of translational engineering in health and medicine, 2017Co-Authors: Paolo Melillo, Daniel Riccio, Luigi Di Perna, Gabriella Sanniti Di Baja, Maurizio De Nino, Settimio Rossi, Francesco Testa, Francesca Simonelli, Maria FrucciAbstract:Color vision deficiency (CVD) is an extremely frequent vision impairment that compromises the ability to recognize colors. In order to improve color vision in a subject with CVD, we designed and developed a wearable improved vision system based on an augmented reality device. The system was validated in a clinical pilot study on 24 subjects with CVD (18 males and 6 females, aged 37.4 ± 14.2 years). The primary outcome was the improvement in the Ishihara Vision Test score with the correction proposed by our system. The Ishihara Test score significantly improved ( $p = 0.03$ ) from 5.8 ± 3.0 without correction to 14.8 ± 5.0 with correction. Almost all patients showed an improvement in color vision, as shown by the increased Test scores. Moreover, with our system, 12 subjects (50%) passed the vision color Test as normal vision subjects. The development and preliminary validation of the proposed platform confirm that a wearable augmented-reality device could be an effective aid to improve color vision in subjects with CVD.
Richard Mccleary - One of the best experts on this subject based on the ideXlab platform.
-
Ishihara Test performance and dementia
Journal of the Neurological Sciences, 1996Co-Authors: Richard Mccleary, Rodman W Shankle, Ruth A Mulnard, Malcolm B DickAbstract:Ishihara trail-tracing (TT) and number-naming (NN) Tests were administered to a clinical sample of 378 demented patients. Error counts on TT and NN Tests were best fit by a negative binomial (overdispersed Poisson) distribution. TT, NN, and combined (TT + NN) error counts were regressed on patient characteristics (sex, age, and education), severity of cognitive impairment (Mini-Mental State Exam: MMSE), dementia stage (Clinical Dementia Rating: CDR), etiology, onset age, and symptom duration in a negative binomial generalized linear model. Patient characteristics, onset age, and symptom duration had no significant effects on any error count. The effects of MMSE, CDR, and etiology, on the other hand, were highly significant and appear to help discriminate vascular dementia from Alzheimer's disease. MMSE (which taps cognitive skills) correlated with both TT and NN errors. CDR (which taps both cognitive and functional skills) correlated only with TT errors and dementia etiology correlated only with NN errors. These distinct correlational patterns reflect differences between the TT and NN tasks (i.e., trail-tracing vs. number-naming) related to specific brain loci and associated functions. This aspect of the phenomenon suggests that Ishihara Tests have useful clinical applications in dementia.
