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PubMed1984

Assessment of children's colour vision using the Pickford-Nicolson anomaloscope.

The colour vision of 439 boys, aged 4-11 years, was measured by the Pickford-Nicolson anomaloscope and four pseudoisochromatic tests. Matching range and dispersion of mid match point were found to be larger than adult values, but did not decrease with age. However, younger children took longer to establish matching range. Twenty-eight (6.4%) colour defectives were found and it is concluded that the Pickford-Nicolson anomaloscope gives valid results with children.

Age Factors↗
PubMed1980

Traumatically acquired color vision defect.

A 24-year-old man acquired a color vision defect shortly after an accident in which he struck the back of his head. Results of the Farnsworth-Munsell 100-hue test showed that the patient had poor color discrimination in both eyes. His color matches on the Nagel anomaloscope suggested a red/green disturbance. Results from increment threshold testing demonstrated on absence of the blue mechanism. Results of field sensitivity measurements confirmed that foveal vision was mediated by the red or green mechanism. This case showed both similarities and differences to previously reported cases of acquired color vision defects secondary to cortical trauma.

Accidents, Traffic↗
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↗
PubMed1995

[Panel D-15 test under reduced illumination for persons with color vision defects].

We evaluated the panel D-15 test under reduced illumination in subjects with color vision deficiency and in normal subjects. Forty subjects with color vision deficiency (3 protanopes, 10 protanomalies, 10 deuteranopes, 7 extreme deuteranomalies and 10 deuteranomalies) and 10 normal subjects were the subjects for the experiment. Seven light levels ranging from 0.9 to 900 lux were used. All normal subjects passed the test at 3.5 lux or more and 30% failed at 0.9 lux. Color vision defective subjects began to fail the test at 225 lux, with 56% failing at 3.5 lux and 92% at 0.9 lux. The performance on the panel D-15 test decreased in proportion to decreasing the illumination in some color vision defective subjects. Some protanomalous subjects showed a deutan pattern at low illumination levels.

Adolescent↗
PubMed1995

Recognition performance of subjects with color-vision deficiencies on a polychromatic sonar screen for ship navigation.

To facilitate differentiation between objects that are approaching, stationary, and moving away, these objects are represented in different colors on the screens of sonar locating devices used in ship navigation. Yellow represents stationary objects, and represents approaching objects, and green represents those objects moving away. A total of 46 subjects with normal color vision and 184 individuals with color-vision deficiencies, among them 29 deuteranopic, 100 deuteranomalous, 21 protanopic and 34 protanomalous individuals, were investigated for their ability to identify different signals. Ten different objects were presented for a period of 64 s each. As a minimal requirement it was established that 50% of the respective experimental group be capable of recognizing the objects within half of this time. Whereas 73.3% of the subjects with normal color vision could meet this requirement, none of the subjects in the different groups with color-vision deficiencies could do so. Only 16.1% of the deuteranopic subjects, 33.1% of the deuteranomalous individuals, 16.2% of the protanopic subjects, and 37.6% of the protanomalous individuals detected all objects within 32 s. No appreciable difference in the ability to recognize signals occurred among the different groups of subjects with color-vision deficiencies.

Color Perception↗
PubMed1993

[Reference to the Abney effect within the scope of linear opponent-color theory].

The Abney effect states that desaturation of spectral colours does not only change their chromatic saturation but also their hue. By means of Hering's perceptual criteria "neither blue nor yellow" and "neither green nor red" and heterochromatic brightness matching, chromaticity loci were measured in a visual tri-stimulus colorimeter; the loci served for construction of an opponent-colour triangle and the associated opponent-colour space. The chromaticity line resulting from the perceptual criterion "neither green nor red" deviated markedly--as an expression of the Abney effect--from a straight line. This phenomenon was captured by piecewise linearizing. The transformation of the (known) fundamental colour space, which may be interpreted as a cone excitation space, onto the opponent colour space thus gained yielded an explicit opponent-colour theory that reproduces some aspects of the Abney effect.

Color Perception↗
PubMed1995

The dyschromatopsia of optic neuritis: a descriptive analysis of data from the optic neuritis treatment trial.

PURPOSE: We sought to characterize the dyschromatopsia of optic neuritis, to determine the type and severity of color defect present and its relation to central vision and spatial acuity, to examine changes in this dyschromatopsia over time, and to determine the applicability of Köllner's rule to patients with optic neuritis. METHODS: We analyzed the raw data on color vision performance as assembled within the Optic Neuritis Treatment Trial (ONTT). The ONTT was designed to evaluate corticosteroids as a treatment for acute demyelinating optic neuritis and to allow long-term outcome and natural history analyses. Between July 1, 1988 and June 30, 1991, 488 patients were enrolled in this trial. All patients underwent extensive neurologic and ophthalmologic examinations including standardized testing of visual function that included testing of color vision. The ONTT population thus afforded a unique opportunity to characterize acquired dyschromatopsias in a large, homogenous, well-characterized cohort of patients with optic neuritis. We used quantitative analysis of FM-100 scores from this patient cohort to determine the severity of the dyschromatopsia, the selectivity of the dyschromatopsia (polarity of errors) and the type of dyschromatopsia (axis of confusion) by employing quadrant analysis of FM-100 scores. RESULTS: The results of high-and low-selectivity analyses of the FM-100 data showed that during the acute phase of optic neuritis, blue/yellow, red/ green, and non-selective color defects occurred; among patients with pure defects, blue/yellow defects were more frequent than red/green defects. At 6 months after the acute event, however, analyses showed that red/green defects were more common than blue/yellow defects. Among patients with selective color defects both acutely and at 6 months, the defect was as likely to change over time as remain the same. The likelihood of persistent dyschromatopsia at 6 months was related to the severity of initial central acuity loss, but the type of dyschromatopsia present (red/green versus blue/yellow) was not. CONCLUSIONS: Our results suggest that at the time of the acute attack of optic neuritis, the majority of selective color defects were blue/yellow defects, whereas at 6 months, more of the selective defects were red/green defects, though both types of defects (as well as nonselective defects) were seen acutely and at 6 months. Despite the rigorous inclusion criteria of the ONTT, the large number of patients we studied, correlation of color vision with visual acuity, and longitudinal follow up, this study showed that no single type of color defect was consistently associated with optic neuritis. Demyelinating optic neuritis does not obey Köllner's rule. Moreover, the type of defect present changed in some patients over the course of recovery. Thus, the type of defect may not even be consistent in individual patients as they recover. The type of defect appeared to be related to spatial vision at the time of the test, but the type of defect present at 6 months was not related to the severity of the initial visual loss. Therefore, in evaluating color defects associated with optic neuritis, the level of central visual function must be considered.

Acute Disease↗
PubMed1995

Colour contrast sensitivity in patients with age-related Bruch's membrane changes.

Patients with bilateral drusen as a manifestation of early age-related macular degeneration (AMD) may have minor psychophysically detectable visual defects in the presence of normal visual acuity. In a variety of retinal diseases, one of the earliest changes in visual processing is an impairment of normal colour vision. This study was undertaken to evaluate colour vision deficits in patients with macular drusen and to determine whether changes in colour contrast sensitivity may occur over time. In a prospective study, colour vision in 84 eyes of 84 patients aged 55-84 years (mean, 68.89 +/- 6.23 years) with macular drusen and clear media was tested using a computer graphics technique. A total of 47 patients were reviewed annually for up to 2 years and measurements were obtained at annual intervals. Colour contrasts sensitivity along protan, deutan and tritan colour confusion lines was determined at a foveal and a parafoveal region. The sensitivity to all stimuli showed large variations between patients. The thresholds for foveal blue-colour contrast sensitivity were elevated and increased during the review period. In contrast, there was no significant change in sensitivity with time for red and green at the foveal or parafoveal region. Tritan threshold changes suggest that the SW cone-receptor population is more susceptible to damage associated with early age-related macular disease than are red or green cones. The results indicate that blue colour contrast sensitivity determined over time may serve as a measure to assess the progression of age-related maculopathy prior to the manifestation of atrophic or exudative macular lesions associated with visual loss.

Aged↗
PubMed1996

Foveal color and luminance sensitivity losses in glaucoma.

BACKGROUND AND OBJECTIVE: Losses in color vision sensitivity are noted in patients with glaucoma and these losses can occur before the onset of visual field defects in ocular hypertensive patients. The authors incorporate a technique that measures foveal luminance and isoluminant-color thresholds. PATIENTS AND METHODS: This study included 31 patients with glaucoma, 10 patients suspected of having glaucoma, and 67 control subjects. The testing conditions measured thresholds under identical spatial and temporal conditions. Individual differences in luminosity between colors were controlled by presenting 16 different ratios of the three phosphors on a color monitor. RESULTS: Relative to the control subjects, the patients with glaucoma showed a nonselective defect in both color and luminance sensitivity for red-green stimuli (P < .05), but a selective color defect for yellow-blue stimuli (P < .01). There were no statistically significant differences between patients suspected of having glaucoma and control subjects (P > 0.3). CONCLUSION: If the isoluminant-color stimuli are detected by foveal P-ganglion cells, then these results suggest that glaucoma leads to a generalized decrease in P-ganglion cell sensitivity that is more pronounced for cells with an input from cones sensitive to short wavelengths.

Adult↗
PubMed1996

Comparison of the standard pseudoisochromatic plates--Parts 1 and 2--As screening tests for congenital red-green color vision deficiencies.

BACKGROUND: The Standard Pseudoisochromatic Plates-Part 2 (SPP-2) are designed primarily as a screening test for acquired color vision deficiencies. However, results from several studies suggest that the SPP-2 may also be effective as a screening test for congenital red-green color vision defects. METHODS: In this study, the screening effectiveness of the SPP-2 was compared with the Standard Pseudoisochromatic Plates-Part 1 (SPP-1) to determine whether clinicians must use both tests: the SPP-1 to screen for congenital color vision defects and the SPP-2 to screen for acquired color vision defects. RESULTS: The results showed that, when using the recommended scoring criterion for the SPP-1, the SPP-2 test is slightly more sensitive in detecting congenital red-green defects. CONCLUSIONS: Clinicians can use the SPP-2 to screen for both congenital and acquired color vision defects.

Adolescent↗
PubMed1996

Color vision measured with pseudoisochromatic plates at five-and-a-half years in eyes of children from the CRYO-ROP study.

PURPOSE: To investigate the prevalence of color deficits at age 5 1/2 years in preterm children with birth weights of less than 1251 g who participated in the multicenter Cryotherapy for Retinopathy of Prematurity (CRYO-ROP) study. METHODS: Two cohorts of CRYO-ROP participants served as subjects: 1055 children who participated in a long-term study of the natural history of ROP at 5 of the 23 CRYO-ROP centers, and 187 children (from all 23 study centers) who had threshold ROP in both eyes and who were randomized to receive cryotherapy in 1 eye. Monocular color vision was tested at age 5 1/2 years, using the Standard Pseudoisochromatic Plates, part 2 (SPP2) for acquired color vision defects. RESULTS: In the Natural History cohort, prevalence of red-green (R-G) color deficits was 6.6% for males and 1.0% for females, similar to that of the general adult population. Prevalence of blue-yellow (B-Y) color deficits was 2.8% for males and 2.2% for females, more than 200 times that in the general adult population. Prevalence of B-Y deficits was not related to birth weight, gestational age, acute-phase ROP, optic atrophy, or retinal residua of ROP, but was related to visual acuity. In the Threshold ROP cohort, color vision deficits were no more likely in eyes that had received cryotherapy than in control eyes. CONCLUSIONS: The results confirm an increased prevalence of B-Y deficits in children born before term, and provide evidence that the increased prevalence is not related to birth weight, gestational age, or severity of ROP within this group of preterm children. No evidence was found to indicate that cryotherapy increased the rate of color vision deficits in eyes with threshold ROP.

Birth Weight↗