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PubMed1995

[Study on color misnaming among the congenital color vision anomalous--Part 1. The tendency in color misnomer].

I report the hue and the color misnomers of 16 subjects with protanopia (color misnomers: 500) and 66 subjects of deutanopia (color misnomers: 2,056), and the color misnomers used by over 10 subjects each and their numbers. Green was the most frequent misnomer, followed by grey, yellow-green, purple, and brown. The deutanopia patients frequently used the Munsell color notation RP for grey. Many of the subjects who misnamed 11 times or more failed the Panel D-15 test. They were diagnosed as having strong color anomaly in the Ohkuma isochromatic plates and in the Tokyo Medical College isochromatic plates. The misnomers were most frequent among the neighboring hues. The severer the anomaly, the further the separation from the test color, and then the misnomers crossed the achromatic confusion line. Judging from the misnomer variation, the color sense of color anomaly does not necessarily seem to be constant. Moreover, liaison was noticed among red, brown, green, or occasionally purple in terms of misnaming pattern. Grey and pink were also linked in misnaming. Lightness was considered to play a strong role in these confusions.

Adolescent↗
PubMed2003

Complex distribution of avian color vision systems revealed by sequencing the SWS1 opsin from total DNA.

To gain insights into the evolution and ecology of visually acute animals such as birds, biologists often need to understand how these animals perceive colors. This poses a problem, since the human eye is of a different design than that of most other animals. The standard solution is to examine the spectral sensitivity properties of animal retinas through microspectophotometry-a procedure that is rather complicated and therefore only has allowed examinations of a limited number of species to date. We have developed a faster and simpler molecular method, which can be used to estimate the color sensitivities of a bird by sequencing a part of the gene coding for the ultraviolet or violet absorbing opsin in the avian retina. With our method, there is no need to sacrifice the animal, and it thereby facilitates large screenings, including rare and endangered species beyond the reach of microspectrophotometry. Color vision in birds may be categorized into two classes: one with a short-wavelength sensitivity biased toward violet (VS) and the other biased toward ultraviolet (UVS). Using our method on 45 species from 35 families, we demonstrate that the distribution of avian color vision is more complex than has previously been shown. Our data support VS as the ancestral state in birds and show that UVS has evolved independently at least four times. We found species with the UVS type of color vision in the orders Psittaciformes and Passeriformes, in agreement with previous findings. However, species within the families Corvidae and Tyrannidae did not share this character with other passeriforms. We also found UVS type species within the Laridae and Struthionidae families. Raptors (Accipitridae and Falconidae) are of the violet type, giving them a vision system different from their passeriform prey. Intriguing effects on the evolution of color signals can be expected from interactions between predators and prey. Such interactions may explain the presence of UVS in Laridae and Passeriformes.

Amino Acid Sequence↗
PubMedDate not supplied

[Color vision in school children: evaluation of a new test]

OBJECTIVE: To compare standard color vision test results (Ishihara test) with a new test developed by the authors ("crayon" test) for the detection of congenital dyschromatopsia. METHODS: Cross-sectional study of 712 children from three public schools and one private school in the city of Porto Alegre, state of Rio Grande do Sul. Children with learning disabilities, or systemic and ocular diseases were excluded from this random sample. Two color vision tests, Ishihara test (short version with 14 plates) and crayon test (developed by the authors) were sequentially applied. Each test was applied by different evaluators and analyzed by a third evaluator. RESULTS: The crayon test showed a specificity of 100% (99.3-100%) and sensitivity of 38.5% (15.1-67.7%) when compared to Ishihara test. The prevalence of congenital dyschromatopsia in this population sample was 2.6% for male children, and 0.9% for female children. CONCLUSIONS: The crayon test results showed greater specificity than Ishihara test in the studied group; however, sensitivity was not adequate for a screening test. It is necessary to improve the sensitivity so that congenital dyschromatopsia can be detected by the crayon test.

Journal Article↗
PubMed1998

M- and L-cones in early infancy: III. Comparison of genotypic and phenotypic markers of color vision in infants and adults.

Genetic analyses were performed on five male children (approximately 3 years), two suspect color-normals and three suspects for congenital color vision deficiencies. These classifications were based on visually-evoked potential (VEP) responses to M- and L-cone-isolating stimuli obtained in a previous study when each subject was either 4- or 8-weeks old. The present analyses were performed in a blind study to characterize the genotypes of these subjects. Four male adults with various color vision phenotypes were also tested as a control. DNA was isolated using a non-invasive technique followed by polymerase chain reaction (PCR) amplification and restriction enzyme analysis to examine the genomic DNA of each subject. The genetic analyses confirmed the VEP identification of two color defective infants, and were consistent with the diagnosis of two other infants as color normal. A third infant was predicted by VEP analysis to have a protan defect, but he did not have a gene array typically found in protan observers.

Child, Preschool↗
PubMed1990

[Diabetes and color vision disorder detected by the Farnsworth 100 Hue test. Diabetic dyschromatopsia].

Farnsworth 100 Hue test was used to investigate color vision in 100 diabetic patients. Blue Yellow axis dyschromatopsia was found in 66.5% of patients. Such a dyschromatopsia precedes diabetic retinopathy in 55% of patients. Its frequency increased as a function of the increasing severity of diabetic retinopathy. On the other hand, 36% of the patients suffering from dyschromatopsia misinterpreted the self-monitoring (urine and blood) tests. These results suggest that the investigation of color vision may be a useful tool for the early screening of diabetic retinopathy particularly in self-monitoring patients.

Adolescent↗
PubMed2004

[Color vision and the diagnosis of reduced visual acuity].

Unexplained visual acuity loss requires a systematic approach to gather as many findings of diagnostic value as possible. Most retinal or optic nerve diseases are accompanied by color vision disorders. The type and severity of color vision disorders may provide additional diagnostic or guiding information or may uncover aggravating or simulating factors.

Adult↗
PubMed1999

[Analysis of fusion points in hybrid genes and gene deletion for congenital red-green color vision defects].

OBJECTIVE: To investigate gene deletion and the fusion points of hybrid genes in congenital red-green color vision defects. METHODS: Genomic DNA was collected from 11 protans, 19 deutans and 5 normal controls. Promoter and exons 2-5 of the red and green pigment genes in these subjects were analyzed by using PCR-Heteroduplex-SSCP analysis. The origin and component of each individual gene were determined by comparison with the patterns of known sequence of the red and green visual pigment genes. RESULTS: Fourteen out of the 30 patients with red-green color vision defects were found to have hybrid gene. The fusion points of the hybrid gene were located in exon 1-intron 1(4 cases), introns 2-3(5 cases) and intron 4 (5 cases). CONCLUSION: The fusion point of a hybrid gene may occur in exon 1-intron 1 and intron 4 as well as in introns 2-3(including exon 3).

Artificial Gene Fusion↗
PubMed1989

Tetrachromatic color vision in the goldfish becomes trichromatic under white adaptation light of moderate intensity.

Spectral sensitivity of the goldfish was measured under white room light of 5 lx and 1.5 lx illuminance, using a behavioral training technique. Compared with the result obtained under 25 lx (Neumeyer, 1984), the functions differed remarkably in the mid- and longwave spectral ranges. Under 1.5 lx, the longwave maximum was absent, and wavelength discrimination was impossible in the mid- and longwave range (between 555 and 663 nm). This indicates that the longwave cone type does not contribute to color vision in these conditions. Since discrimination ability was not affected in other spectral ranges, we conclude that color vision is trichromatic then, being subserved by the ultraviolet, the short- and the midwave cone types only. Under 5 lx, the longwave cone type contributes to color vision, but, as shown in color mixture experiments, to a lesser extent.

Adaptation, Ocular↗
PubMed2003

Pilot study on prevalence of color vision dysfunction in long-term solvent-exposed painters.

Main purpose of our study was to examine whether painters with long-term exposure to mixtures of organic solvents show slight dysfunctions in color vision ability. The study population consisted of 140 men with chronic exposure to organic solvents from paint and thinners (mean duration of exposure: 26 years). We used the Lanthony Desaturated Panel-D-15 (LDP-D15) to test color vision and calculated the color confusion index (CCI). The results were compared with reference values taken from the literature. Additionally the questionnaire Q18 for solvent related neurotoxic symptoms was applied and its results compared with the CCI. Painters between 25 to 55 years old had higher median CCI values than the respective age group of the references. No statistical significant association between CCI and the actual or chronic solvent exposure was found. The results of the Q18 did also not correlate significantly with the exposure indices. We recommend further studies to explore if the color confusion index is an appropriate indicator of early neurotoxic effects in painters.

Color Vision Defects↗
PubMed2004

Analysis of L-cone/M-cone visual pigment gene arrays in Japanese males with protan color-vision deficiency.

The L-cone/M-cone visual pigment gene arrays were analyzed in 125 Japanese males with protan color-vision deficiency. Arrays were successfully determined in 62/65 subjects with protanopia and 57/60 protanomaly subjects. Among the 62 protanopia subjects, 48 (77%) had an array consisting of a single 5' L-M hybrid gene (PS-array) or a 5' L-M hybrid gene followed by an M gene(s) that was structurally identical to the hybrid gene (PI-array). In the remaining 14 subjects, 11 had an array consisting of a 5' L-M hybrid gene followed by an M gene(s) that was structurally different from the hybrid gene (PD-array) and 3 subjects had an apparently normal array consisting of a single L gene followed by an M gene(s) (PN-array). In the 11 subjects with the PD-array, subject A67 had an 11 bp-deletion in exon 3 of the downstream genes and 6 had an A-71C substitution in the second gene of the array. In the 3 subjects with the PN-array, subject A289 had a missense mutation (Pro231Leu) in exon 4 of the L gene. When the function of the missense mutation was studied by in vitro reconstitution of visual pigments, it was found to be deleterious to both cone opsin and rhodopsin. Among the 57 protanomaly subjects, 49 (86%) had the PD-array, but 25 subjects had a difference only in exon 2 between the first and downstream genes that suggested a contribution of exon 2-encoded difference in the M pigment to color-discrimination. In the remaining 8 subjects, 2 had the PS-array, 2 had the PI-array and the other 4, including subject A89 with a missense mutation (Glu338Gly) in the L gene, had the PN-array. Genotype-phenotype relationships in protan color-vision deficiency are discussed.

Color Vision Defects↗
PubMed1990

Polymorphism in normal human color vision and its mechanism.

Earlier we reported that Rayleigh matches made by males with normal color vision fall into distinct groups, and proposed that this behavior reflects an X-chromosome linked polymorphism in the spectral positioning of cone pigments (Neitz & Jacobs, 1986). In the present experiments two different color matches were obtained from each of 60 color normal males. Comparisons of the data from these two matches allowed variations in color matching that are produced by individual differences in the spectral positioning of middle and long wavelength cone pigments to be distinguished from color vision variations caused by other factors. Considered together with findings from molecular biology and spectral measurements of individual cone pigments, these results suggest that among color normal humans: (1) there are discrete variations in both middle and long wavelength cone pigments, and (2) most individuals have more than three different cone pigment types.

Color Perception↗
PubMed1989

[Color vision under different luminosity in various fundus diseases].

Reports on the utilization of the color vision test as a method for detecting early abnormality in fundus diseases have been published. The author performed the 100-hue test at five luminous stage levels set between 10 and 2000 lux in cases of glaucoma, diabetic retinopathy and central chorioretinopathy. The progressive degree of each disease and the level of disorder seen in color vision were assessed comparatively at each luminous level to determine adequate luminosity for performing the 100-hue test. For classification of the degree of progression in each disease, visual acuity, visual field and C/D ratio were used for glaucoma. Visual acuity, type of retinopathy and the period of contracting the disease were used for diabetic retinopathy, and visual acuity was used for central chorioretinopathy. As a result, the total error score in the 100-hue test closely correlated to the degree of progression of each disease and the luminosity for performing the most effective 100-hue test was found to be 100 lux.

Adult↗
PubMed1997

Evaluation of Kojima-Matsubara color vision test plates: validity in young children.

PURPOSE: We examined a pseudoisochromatic color plate test by Kojima and Matsubara for young children which uses drawings of familiar objects rather than letters or numbers. First, we evaluated the test's efficacy as a color deficiency screener and its validity in classifying the types of color deficiencies by comparing its results with those from the Moreland anomaloscope. Second, we eliminated the chromatic factor and evaluated the functional ability of young children to perform the task by determining how many correct responses were obtained using modified black/white replicas of the test plates. METHODS: Part 1: Twenty color-normal and 13 color-deficient adults were diagnosed and classified with the Ishihara test, Panel D-15 test, and anomaloscope. Subjects were then tested with the Kojima-Matsubara test and result were compared with those from the anomaloscope. Part 2: Fifty children aged 3 to 7 years were tested with modified black/white test plate replicas. The number of correct responses for each plate was determined for five different age groups. RESULTS: Part 1: Among the 20 color-normal subjects, 18 read all 10 plates correctly and 2 subjects missed 1 of the 10. Only 1 of the 13 color-deficient subjects exhibited the expected responses for plates 2 to 6 (used for color deficiency screening). The color-deficient subjects' responses for plates 7 to 10, which are used to classify red-green defects, were varied and only the protanomalous subjects (n = 2) followed the expected response pattern. Part 2: Of the 10 black/white modified plates, only 2 were correctly identified by all 50 children. The other plates had a recognition rate that ranged from 32 to 98%. CONCLUSIONS: Because the response patterns given by most of the color-deficient adult subjects were different from those in the test manual, ambiguous results would occur if the Kojima-Matsubara test were used for color vision screening or the diagnosis of color deficiency. In addition, the difficulty that many of the young children exhibited in identifying the objects in the black/white replica plates suggests that there would be a large number of false positive errors (classifying a color normal as color deficient) when using this test in young children.

Adult↗