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At least 1,621 records · Page 90Linked to original sources

Ophthalmologic manifestations of Alzheimer's disease.

Alzheimer's disease is a progressive neurologic disorder which may present with visual disturbance before the diagnosis is clearly established. Central acuity and visual field are initially normal. Alzheimer patients may show anomalies of color vision, spatial contrast sensitivity, susceptibility to visual masks, fundus examination, ocular motility, higher cortical visual function, visual evoked potential, and pattern electroretinogram. Pathologic analysis has shown abnormalities at all levels of the visual axis from retinal ganglion cell to associative visual cortex. Correlations between the visual abnormalities of Alzheimer's disease and corresponding neuroanatomic substrates are discussed.

Adult↗

Are visual anomalies related to reading ability?

Although reading ability is known to be related to a large number of factors, when a child having a reading problem is brought to an optometrist he (or she) has the responsibility of determining whether or not a visual anomaly may be a major or contributing cause of the reading problem. A review of the literature indicates that myopia is consistently associated with good reading performance; and that hypermetropia, astigmatism, lateral phorias, poor fusional vergences, strabismus and color vision anomalies tend to be associated with poorer than average reading performance. Well-designed and well-controlled studies are needed, particularly concerning the effect on reading ability of the correction of visual anomalies. Until such studies have been done, any child who has a reading problem deserves a thorough optometric or ophthalmologic examination and the correction of any visual anomalies found.

Astigmatism↗

Visual evoked potentials and ibuprofen (Motrin) toxicity.

A patient taking ibuprofen (Motrin) for the relief of osteoarthritis developed, after two months, decreased visual acuity and decreased color vision. Initially the Visual Evoked Potentials, showed decreased wave amplitudes, and increased conduction times in both eyes. After stopping the drug, the Visual Evoked Potentials returned to normal one month before the visual acuity improved. We feel that Visual Evoked Potentials are useful for screening patients on ibuprofen, and prognosticating their recovery, when a secondary toxic optic neuritis develops.

Aged↗

A visual profile of the alcoholic driver.

Some visual characteristics of the chronic alcoholic were investigated in a sample of 100 male alcoholic patients and 100 matched controls. The purpose of the retrospective study was to determine whether these characteristics may contribute to an increased motor vehicle accident rate among alcoholics. Significant differences between the two groups, which might affect driving abilities, were found for color vision deficiencies and the breakage and loss rate of spectacles. No significant differences were found for stereopsis deficiencies, limitation of visual field, distance phorias, ductions, or the need to wear spectacles for driving. An analysis of the refractive data suggests that alcoholic patients may be slightly more hyperopic and less astigmatic than others; however, these differences are not sufficient to influence driving ability.

Alcoholism↗

Atypical retinitis pigmentosa: a report of three cases.

We report three cases of patients with atypical retinitis pigmentosa (RP): sector bilateral, sector unilateral, and inverse. Clinical and functional features of perimetry, color vision testing, adaptometry, electroretinography, fluorangiography, and audiometry are described. One patient had isolated RP; the others had syndromic RP, combined with defective hearing and celiac disease. Two of these patients were followed for three years and one for 13 years. Their disease courses during the period of observation are discussed.

Adult↗

Cutaneous melanoma-associated retinopathy.

PURPOSE: To define further the syndrome of cutaneous melanoma-associated retinopathy, of which only five affected patients have been reported previously. METHODS: Three men with melanoma-associated retinopathy were examined and studied electrophysiologically. Two were studied in detail psychophysically. RESULTS: Visual symptoms consisted of flickering black and white spots, shimmering patches of colors, and night blindness. The onset was acute and nonprogressive. Reduced amplitudes were observed in the flash electroretinographic b-wave and the pattern electroretinogram. Color vision, contrast sensitivity, and light- and dark-adapted perimetric sensitivities were abnormal. In one patient, the rate of dark adaptation was normal with elevated final cone and rod thresholds. CONCLUSIONS: Melanoma-associated retinopathy is a paraneoplastic syndrome distinct from cancer-associated retinopathy with a different visual prognosis. It may preferentially affect men.

Aged↗

Clinical and genetic analysis of a family affected with dominant optic atrophy (OPA1)

OBJECTIVES: To refine the dominant optic atrophy locus, OPA1, on chromosome 3q and to characterize the phenotype of a 6-generation family pedigree affected with this disease. METHODS: Fifty-six family members had a complete eye examination. Clinical records of an additional 3 patients were reviewed. Goldmann perimetry and a 21-chip subtest of the Farnsworth-Munsell 100-Hue test were performed on selected patients. Affected patients, unaffected siblings, and potentially informative spouses were genotyped with short tandem repeat polymorphisms located on chromosome 3. The genotypic data were subjected to linkage analysis. RESULTS: Thirty-four family members were found to be clinically affected. Most experienced vision loss (20/40 or poorer) in the first decade of life. Most (9 of the 16 eyes) progressed to 20/800 or poorer visual acuity by age 60 years, while 2 patients maintained visual acuities of 20/40 at that age. Affected patients had a 2- to 10-fold increase in the error score of a 21-chip subtest of the Farnsworth-Munsell 100-Hue test compared with age-matched unaffected family members. The optic nerve examination revealed temporal pallor and excavation in all affected individuals. Linkage analysis revealed significant lod scores with 9 markers. The highest lod score, 10.1 (theta = 0) [corrected], was obtained with marker D3S2305. Analysis of recombinants narrowed the disease interval to approximately 3.8 centimorgans, flanked by D3S3669 (centromeric) and D3S1305 (telomeric). CONCLUSIONS: Most patients affected with dominant optic atrophy in this family progressed to legal blindness by middle age. Color vision testing is a sensitive method for detection of affected patients. The dominant optic atrophy locus, OPA1, has been refined by the identification of new flanking markers: D3S3669 (centromeric) and D3S1305 (telomeric).

Adolescent↗

Changes in perceived color with intermittent illumination.

Using 24 observers with normal color vision, perceived shifts in hue were determined for a yellow-red, green, and blue-green at intermittencies of 5, 10, and 20 cps. The hue shift for yellow-red was consistent with the hue shift exhibited by a deuteranomalous observer while the hue shift for green and blue-green was consistent with that exhibited by a protanomalous observer.

Color Perception↗

Effects of viewing conditions on standard measures of acquired and congenital color defects.

We examined the effect of variations in viewing distance and viewing duration on the performance of color-normal observers with four standard tests of color vision. Significant effects of the experimental manipulations were obtained: both increasing viewing distance and decreasing viewing duration significantly increased the number of errors made by observers. Moreover, the four tests differed widely in their sensitivity to the variations in viewing conditions. Practical implications of the findings for the administration and selection of plate tests are discussed, and possible mechanisms underlying the results are suggested.

Color Perception↗

Frequent alterations of visual pigment genes in adrenoleukodystrophy.

Both adrenoleukodystrophy (ALD) and red/green color blindness have been mapped to the distal long arm of the human X chromosome (Xq28). Color-vision defects are frequently associated with ALD, and study of the red and green visual pigment genes in eight ALD kindreds has shown frequent structural changes including deletions and possible intragenic recombinations. Such changes may reflect chromosomal events underlying both ALD and the associated visual defects and should help define both the structural gene responsible for ALD and physical genetic relationships in the Xq28 region.

Adrenoleukodystrophy↗

Categorical color perception: influence of cultural factors on the differentiation of primary and derived basic color terms in color naming by Japanese children.

Color naming tests with Japanese children (age 12-15) in Yonezawa, Tokyo and Düsseldorf (Germany) demonstrate that the primary basic color terms based on Hering's opponent color scheme are not influenced by the increasing Western cultural influence from Yonezawa to Tokyo and to Düsseldorf. The derived color terms for brown, orange and pink hues do appear to be influenced, however. The results support and extend the findings of Uchikawa and Boynton (1987). They verify the hypothesis that the psycholinguistics of color naming are based on a universal neurobiology of human color vision.

Adolescent↗

Color mixture data for normals and tritanopes.

In the author's theory of color vision the blue and the green fundamental fall on a tritanopic confusion line. This provides the basis for comparing the mixture data of a tritanope with those of a normal. At the red end of the spectrum the data conform very well to what is predicted by theory. At the blue end the data point to the possibility that the pigment responsible for the red response may differ from the pigment involved at the red end of the spectrum.

Color Perception↗

Dominant optic atrophy. The clinical profile.

We examined 24 individuals in four family pedigrees with dominantly inherited optic atrophy (DOA); 12 patients met the criteria for diagnosis of DOA and two were suspect. Our data indicate that (1) insidious onset usually occurred in childhood, but subjective visual symptoms may evolve in adulthood; (2) visual function was minimally (20/25) to moderately (20/400) abnormal, could be strikingly asymmetric in an individual (eg, 20/30 in the right eye and 20/200 in the left eye), and showed considerable intrafamilial and interfamilial variation; (3) visual field defects consisted of central and centrocecal scotomas, but no peripheral isopter abnormalities were found; (4) color-vision screening with Hardy-Rand-Rittler plates revealed dyschromotopsias, but only Farnsworth-Munsell 100-hue examination disclosed the typical tritan defects; (5) pattern-reversal visual-evoked responses were characterized by diminished amplitudes and prolonged latencies, consistent with neural conduction defects; (6) disc pallor was limited to the temporal segment in all cases, and 16 of 24 eyes showed focal temporal excavation, which is probably pathognomonic of DOA.

Adolescent↗

Flipping coins in the fly retina.

Color vision in Drosophila melanogaster relies on the presence of two different subtypes of ommatidia: the "green" and "blue." These two classes are distributed randomly throughout the retina. The decision of a given ommatidium to take on the "green" or "blue" fate seems to be based on a stochastic mechanism. Here we compare the stochastic choice of photoreceptors in the fly retina with other known examples of random choices in both sensory and other systems.

Animals↗

Color and language: worldwide distribution of Daltonism and distinct words for "blue".

A geographical review of the published literature confirmed that red-green color-vision deficiency (Daltonism) is rare near the equator and more prevalent at higher latitudes, as others have reported. A survey of dictionaries of the languages spoken by the populations for which Daltonism data are available confirmed that distinct words for "blue" are also rare near the equator, and more common at higher latitudes. These results were compared to show an even stronger relation between the proportion of languages with a word for "blue" and the prevalence of Daltonism. We believe that the strong correlation between "blue" and Daltonism suggests that an evolutionary, physiological cause for both phenomena.

Color↗

Cone dysfunction and supernormal scotopic electroretinogram with a high-intensity stimulus. A report of three cases.

An unusual form of scotopic electroretinogram with a bright white stimulus, which consisted of a rectangular a-wave of normal amplitude and a b-wave of supernormal amplitude, was recorded in three patients with cone dysfunction. In addition to poor visual acuity, abnormal color vision and reduced amplitude of the photopic electroretinogram, these patients showed a 2-log unit elevation of the dark-adaptation threshold. Funduscopic examination and fluorescein angiography revealed fine granular pigment disturbances at the macula. The relationship between the response of the dark-adapted electroretinogram versus stimulus intensity was unique to these patients. The b-wave thresholds were elevated by 1 log unit. The b-waves were reduced in amplitude and markedly delayed in implicit time to dim stimuli, but supernormal in amplitude and normal in implicit time to bright stimuli.

Adolescent↗

Heterozygote detection in X-linked recessive incomplete achromatopsia.

Carrier women in a family with X-linked incomplete achromatopsia (XLIA) were evaluated by means of ophthalmologic examinations, psychophysical tests, and electroretinography (ERG). Ophthalmologic examinations of five obligate carrier women and three women at 50% risk were normal except for the finding of high myopia in one carrier and one woman at risk. Detailed color vision testing was normal in all eight women. By contrast, the corneal full-field ERGs of three of five obligate carriers and two of three women at risk displayed major, qualitatively similar abnormalities of their cone components that were readily detected by our quantitative method. These b-wave alterations were similar in all five women regardless of refractive error. Our findings suggest that the ERG can identify some women who carry the gene for this X-linked recessive condition who are normal by clinical and psychophysical testing.

Adult↗