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PubMed1997

Color vision defect type and spatial vision in the optic neuritis treatment trial.

PURPOSE: To describe the types of color vision defects present in the acute phase of the disease and 6 months into recovery in the 438 participants of the Optic Neuritis Treatment Trial. METHODS: Patients meeting strict eligibility criteria were seen within 8 days of the onset of symptoms and then at regular follow-up visits. At the first and 6-month visits (and subsequent annual visits), spatial vision (acuity, contrast sensitivity), visual fields, and color vision were measured. Farnsworth-Munsell 100-hue tests were scored by a variant of the method of quadrant analysis described by Smith et al (Am J Ophthalmol. 1985; 100:176-182). RESULTS: Most persons show mixed red-green (RG) and blue-yellow (BY) color defects (one type predominating, accompanied by a lesser defect of the other type). BY defects tend to be slightly more common in the acute phase of the disease, with slightly more RG defects at 6 months. Persons may shift defect type over time. Defect type was not related to any of the spatial vision measures at either test time or to treatment group; however, severity of color defect was related to both spatial vision measures and treatment group. CONCLUSIONS: Contrary to common clinical wisdom, optic neuritis is not characterized by selective RG defects. Color defect type cannot be used for differential diagnosis of optic neuritis.

Acute Disease↗
PubMed2005

Color vision and contrast sensitivity in epilepsy patients treated with initial tiagabine monotherapy.

The purpose of the study was to determine whether the use of a GABAergic antiepileptic drug (AED), tiagabine, affects color vision and contrast sensitivity. Twenty newly diagnosed patients with partial epilepsy (aged 19-72 years), receiving tiagabine as their initial monotherapy for 5-41 months were examined. Color vision was examined with the Standard Pseudoisochromatic Plates 2 (SPP2), with the Farnsworth-Munsell 100 Hue Test (FM100) and with the Color Vision Meter 712 (CVM) anomaloscope. Contrast sensitivity was measured with the Pelli-Robson letter chart. Three patients excluded from the color vision evaluation for congenital red-green color vision defects. Seven out of 17 patients (41%) had acquired color vision deficit examined with the FM100. The CVM anomaloscope revealed minor defects in two patients. Contrast sensitivity function was within normal ranges. The present study suggests that AED therapy with tiagabine, like with other established and newer AEDs may interfere with color perception.

Adult↗
PubMed1985

Chromatic perception in relation to an hypothesized cerebral dominance.

On the basis of the cerebral dominance, we have hypothesized an asymmetry (for saturation or brightness) between the two eyes in perception of chromatic stimuli. 51 subjects were tested on chromatic perception (green, red, yellow, blue). For each subject also an ocular-dominance score was obtained. The results substantially confirmed the hypothesis of cerebral dominance in color perception. Subjects with high ocular-dominance scores (right- or left-dominant subjects) showed for the green stimulus asymmetric behavior, while subjects with low ocular-dominance scores showed a tendency toward symmetry in perception.

Adult↗
PubMedDate not supplied

Color space distortions in patients with type 2 diabetes mellitus.

Color vision impairment was examined in patients with type 2 diabetes mellitus (DM2) without retinopathy. We assessed the type and degree of distortions of individual color spaces. DM2 patients (n = 32), and age-matched controls (n = 20) were tested using the Farnsworth D-15 and the Lanthony D-15d tests. In addition, subsets of caps from both tests were employed in a triadic procedure (Bimler & Kirkland, 2004). Matrices of inter-cap subjective dissimilarities were estimated from each subject's "odd-one-out" choices, and processed using non-metric multidimensional scaling. Two-dimensional color spaces, individual and group (DM2 patients; controls), were reconstructed, with the axes interpreted as the R/G and B/Y perceptual opponent systems. Compared to controls, patient results were not significant for the D-15 and D-15d. In contrast, in the triadic procedure the residual distances were significantly different compared to controls: right eye, P = 0.021, and left eye, P = 0.022. Color space configurations for the DM2 patients were compressed along the B/Y and R/G dimensions. The present findings agree with earlier studies demonstrating diffuse losses in early stages of DM2. The proposed method of testing uses color spaces to represent discrimination and provides more differentiated quantitative diagnosis, which may be interpreted as the perceptual color system affected. In addition, it enables the detection of very mild color vision impairment that is not captured by the D-15d test. Along with fundoscopy, individual color spaces may serve for monitoring early functional changes and thereby to support a treatment strategy.

Adult↗
PubMed2000

Molecular genetics of color vision and color vision defects.

Color is an extremely important component of the information that we gather with our eyes. Most of us use color so automatically that we fail to appreciate how important it is in our daily activities. It serves as a nonlinguistic code that gives us instant information about the world around us. From observing color, for example, we can find the bee sting on an infant's arm even before it begins to swell by looking for the little spot where the infant's skin is red. We know when fruit is ripe; the ripe banana is yellow not green. We know when meat is cooked because it is no longer red. When watching a football game, we can instantly keep track of the players on opposing teams from the colors of their uniforms. Using color, we know from a distance which car is ours in the parking lot--it is the blue one--and whether we will need to stop at the distant traffic light, even at night, when we cannot see the relative positions of red and green lights.

Color Perception↗
PubMed1978

Colorimetry by a new principle.

A simple and informative method is described for determining the type and extent of color defects. The subjects' responses are registered automatically on a chromaticity diagram that is based on the newtonian model. Color defects are readily identifiable by a skewing of the normal central gray area toward the defectively perceived color. The examination permits independent variation of hue and saturation for each color and requires less than five minutes for the entire procedure. Unlike conventional color tests, the present method indicates exactly what colors are or are not seen at any level of saturation.

Adolescent↗
PubMed1997

Impaired color vision in cocaine-withdrawn patients.

BACKGROUND: The main reinforcing effect of cocaine happens by altering dopaminergic neurotransmission in the brain reward systems. Dopamine is found in high concentrations in the retina in which it plays an important role in color vision. Therefore, we investigated whether cocaine-dependent patients might have impaired color vision. METHODS: We compared patients recently withdrawn from cocaine (n = 31) with matched normal controls (n = 31) on 2 color vision tests. RESULTS: Cocaine-withdrawn patients had significantly higher error scores than matched controls on the Farnsworth-Munsell 100-hue and Lanthony desaturated D-15 color vision tests. Also, 23 of the 31 cocaine-withdrawn patients had blue-yellow color vision losses on the Farnsworth-Munsell 100-hue test compared with 3 controls (P < .001, chi 2 test) and 15 had blue-yellow color vision loss on the Lanthony desaturated D-15 test compared with 2 controls (P < .001, chi 2 test). CONCLUSIONS: These significantly higher test error scores and blue-yellow color vision losses suggest that color vision is impaired in cocaine-withdrawn patients. Color vision testing may be useful in future studies of cocaine-dependent patients.

Adult↗
PubMed1998

Quantitative assessment of color vision impairment in workers exposed to toluene.

Color vision was examined by the Lanthony-D-15 desaturated test in two groups of workers occupationally exposed to toluene and in a control group. Biological parameters of toluene exposure were analyzed: toluene in air and in venous blood, orthocresol, and hippuric acid in urine after workshift. The first exposed group, Group E1, comprised 41 workers (toluene exposure ranged from 11.30 to 49.30 ppm), and the second exposed group, Group E2, comprised 32 workers (toluene exposure ranged from 66.00 to 250.00 ppm). The nonexposed group, Group NE, comprised 83 subjects. Each group was divided into two subgroups; alcohol consumers and nonconsumers. Color vision loss was expressed as a color confusion index (CCI) and as age and alcohol intake-adjusted color confusion index (AACCI). Significantly higher values of CCI and AACCI (both P < 0.0001) in Group E2 in comparison to Group NE, and significantly higher CCI (P < 0.0001) and AACCI (P < 0.05) values in Group E2 in comparison to Group E1 were established. The significant difference in CCI value between alcohol consumers and nonconsumers was established only in Group NE (P < 0.05). In Group NE significant correlation was found between CCI value as a dependent and age and alcohol intake as independent cofactors (R2 = 0.45; P = 0.0000). In Group E2 significant correlation was established between CCI as a dependent factor and age, toluene in air, and alcohol intake (R2 = 0.72; P = 0.0001), or between CCI as dependent and age, toluene in blood and alcohol intake as independent cofactors (R2 = 0.68; P = 0.0002). In Group E1 significant correlation was established only between CCI and age (P <0.005). In Group E2, AACCI value significantly correlated with toluene in air (P < 0.0001), toluene in blood (r < 0.0005), orthocresol (P < 0.005) and hippuric acid (P < 0.005) in urine after workshift. There were no differences between smokers and nonsmokers in CCI values in the examined groups. Results of this study indicate that toluene in exposed workers can impair color vision. The role of alcohol intake and age influence on color vision loss cannot be ignored in such workers.

Adult↗
PubMed1983

Color vision in albino subjects.

Color vision testing was performed on a group of ten black tyrosinase-positive albino patients and a group of normal subjects. Testing was accomplished by means of a Farnsworth-Munsell (F-M) 100-hue test and Nagel anomaloscope. As a group, the albino patients showed an increase in number of errors scored on the FM-100 hue test, without any specific axis in the majority of cases. Results on the Nagel anomaloscope showed a 'widening' into the red end of the Rayleigh equation. A possible explanation for this apparent widening is discussed, which emphasizes anticipated results of matching ranges obtained on extrafoveal cones.

Adolescent↗
PubMedDate not supplied

Prevalence of congenital color deficiencies in secondary-school students in Tehran.

PURPOSE: A population-based study was conducted to determine the prevalence of color deficiencies in secondary-school students (ages 12-14) in Tehran. METHODS: A total of 2,058 students (1,136 males, 922 females) were examined with Ishihara pseudoisochromatic color plates. RESULTS: In the study population, 97 cases of defective color vision were detected, including 93 males and 4 females. The affected individuals all had negative histories of previous systemic and ocular disease or chronic use of medications. The visual acuity was 20/20 and the fundus was normal in all affected students. Of the 93 cases of defective color vision in males (8.18%), 56 cases (4.93%) involved deuteranomaly, 13 (1.14%) protanomaly, 13 (1.14%) deuteranopia, and 11 (0.97%) protanopia. The four cases in females (0.43%) involved deuteranomaly in three cases (0.32%) and protanomaly in 1 case (0.11%). Deuteranopia and protanopia were not detected in females. CONCLUSION: This is the first study to determine the prevalence of congenital color blindness in Iran. The results agree with reports of prevalence of congenital color blindness from Western Europe.

Adolescent↗
PubMed1992

A new way to use the Ishihara test.

The Ishihara plates are widely used as a test for colour vision. Originally designed for the purpose of detecting congenital red-green colour blindness, the test also has some value in demonstrating acquired colour vision defects. There are, however, several disadvantages in the present arrangement of the plates. A modification of the test, involving the rearrangement of the order of the plates, is presented which, together with a new recording chart, simplifies both the administration and the interpretation of the test.

Color Perception↗
PubMed1992

Color vision in Stargardt's disease.

The color vision of nine patients aged from 13 to 52 years with Stargardt's disease was studied with the following tests: Standard Pseudoisochromatic Plates part 2 (SSP2), Farnsworth-Munsell 100 hue test (FM100), Nagel (red-green) anomaloscope and Besançon (blue) anomalometer. At the beginning of the disease, a very slight defect in red-green color vision could be demonstrated. Later, a distinct acquired red (pseudo-protanomalous) defect in the Nagel anomaloscope and an abnormal error score in the FM100 test were observed. In advanced stages, the red defect became stronger (scotopization) and the FM100 test showed a red-green axis. In the course of the disease, a blue defect with the SPP2 plates and with the Besançon anomalometer could also be found. The visual acuities of the patients had a significant correlation with the matching ranges of the Rayleigh equation and the Moreland equation. The duration of the disease did not show any correlation with the color vision tests.

Adolescent↗