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At least 1,639 records · Page 91Linked to original sources
PubMed1996

Visual outcome in bilateral nonarteritic anterior ischemic optic neuropathy.

BACKGROUND: Nonarteritic anterior ischemic optic neuropathy (NAION) is a common cause of visual loss in the older population. Bilateral NAION is a well-documented entity; however, no study to date has compared the visual outcome between affected eyes. METHODS: The authors retrospectively reviewed the charts of 99 patients with diagnoses of NAION over 3 1/2 years. In the 23 patients with bilateral involvement, 16 were included in the study for analysis of final visual outcome between affected eyes. Snellen acuity, Ishihara color plates, and Humphrey automated perimetry were evaluated as the parameters of visual function. Descriptive analysis of the outcome between affected eyes for each parameter is presented as a frequency distribution of pre-defined groups. Statistical significance is established using nonparametric tests. RESULTS: Bilateral NAION was found in 23% (23/99) of the patients studied. The authors identified a high percent agreement between eyes with regard to visual acuity (81% within 3 Snellen lines), color vision (69% within 3 plates), and Humphrey visual field (75% within 5 decibels of mean deviation). Additionally, there was a statistically significant correlation between affected eyes for all three visual parameters: visual acuity (P = 0.043), color vision (P = 0.001), and Humphrey visual field (P = 0.039). CONCLUSION: The authors found a high percent agreement and statistically significant correlation in final outcome between affected eyes of patients with bilateral NAION for visual acuity, color vision, and visual field loss. With a larger series, it may be possible to predict the visual outcome of the second affected eye based on the parameters of the first eye.

Adult↗
PubMed1985

The effect of ocular pigmentation on intraocular pressure response to timolol.

The one-hour intraocular pressure (IOP) response to topical ocularly applied timolol was studied in darkly and lightly pigmented eyes. One drop of 0.25% 1-timolol was applied to one eye of ten subjects with brown and ten subjects with blue iris color. In the treated and untreated eyes with blue iris color the IOP fell significantly from the baseline value, whereas no pressure reduction was obtained either in the treated or untreated eyes with brown iris color. Beta-blocking agents are known to accumulate in pigment-containing ocular structures. The lack of a one-hour pressure response to timolol in darkly pigmented eyes observed in our study may refer to the reduction of 1-timolol in the biophase due to excessive pigment binding.

Adult↗
PubMed2002

Effect of opacifiers on color stability of pigmented maxillofacial silicone A-2186 subjected to artificial aging.

PURPOSE: This study was designed to determine the effect of opacifiers used at different ratios on the color stability of pigmented A-2186 silicone maxillofacial elastomers and to evaluate the color spectrophotometrically before and after artificial aging. MATERIALS AND METHODS: Sixty experimental groups of elastomers were made using various concentrations (5%, 10%, and 15%) of 4 opacifiers (Georgia kaolin powder neutral, kaolin powder calcined, Artskin white, and dry pigment titanium white) with 1 of 5 dry earth cosmetic pigment groups (no pigment [control], red, yellow ochre, burnt sienna, and a mixture of all pigments). Five specimens of each elastomer were tested, for a total of 300 specimens. All specimens were placed in an aging chamber and artificially aged by exposure to light, water spray, fluctuating temperatures, and humidity. CIE L*a*b* values were measured by spectrophotometer. The color differences (Delta E*) at various exposure energies (150, 300, and 450 kJ/m(2)) were subjected to 4-way analysis of variance with repeated measures (super ANOVA). Mean values were compared with Tukey-Kramer intervals calculated at the 0.05 significance level. RESULTS: The trained human eye can detect color changes (Delta E*) greater than 1.0. Adding all pigments to any of the kaolin groups did not protect silicone A-2186 from color degradation over time. Mixing red pigment in all groups at all times drastically increased DeltaE* values ranging from 0.1 to 1.3 up to 16.6 to 49.6. Yellow ochre had an effect only with 10% and 15% concentrations of kaolin powder calcined, increasing the value of Delta E* to greater than 1.0. Burnt sienna had an effect only with a 15% concentration of kaolin powder calcined, increasing the value of Delta E* at 300 and 450 kJ/m(2) to greater than 11.0. At the 5% concentration, kaolin powder calcined had the smallest color changes, followed by, in order, dry pigment titanium white, Artskin white, and Georgia kaolin. At the 10% concentration, Artskin white had the smallest color changes, followed by, in order, dry pigment titanium white, kaolin powder calcined, and Georgia kaolin. At the 15% concentration, Artskin white again had the smallest color changes, followed by, in order, dry pigment titanium white, Georgia kaolin, and the kaolin powder calcined. The smallest color changes in each kaolin group were at the 10% concentration for Artskin white, dry pigment titanium white, and kaolin powder calcined and at the 5% concentration for Georgia kaolin. CONCLUSIONS: Mixing dry earth cosmetic pigments with opacifiers did not protect silicone A-2186 from color degradation over time, especially in the case of red pigment. The group in which pigments were mixed with 10% Artskin white had the smallest color changes over time, followed by, in order, the groups in which pigments were mixed with 10% dry pigment titanium white, 10% kaolin powder calcined, and 5% Georgia kaolin. Red pigment had a significant effect on all opacifiers, especially Georgia kaolin and kaolin powder calcined. Yellow ochre and burnt sienna had an effect only on 15% kaolin powder calcined. Among all the pigment groups tested, yellow ochre remained the most color stable over time.

Analysis of Variance↗
PubMed1998

Iris color, skin sun sensitivity, and age-related maculopathy. The Blue Mountains Eye Study.

OBJECTIVE: The purpose of the study was to assess relationships between age-related maculopathy (ARM) and iris color, skin sun sensitivity, and other sunlight-related factors. DESIGN: Cross-sectional population-based study. PARTICIPANTS: The Blue Mountains Eye Study performed a detailed eye examination of 3654 residents living in the Blue Mountains area, west of Sydney, Australia. MAIN OUTCOME MEASURES: Subjects with late age-related macular degeneration (late AMD), early ARM, and large drusen (> or = 125 microns diameter) were identified using masked grading of retinal photographs. Iris color was graded using standard photographs, and interviewers collected questionnaire data on sunlight-related factors. Logistic regression, adjusting for age, sex, AMD family history, and current smoking, was used to assess associations. RESULTS: Blue iris color was significantly associated with an increased risk of both late AMD (odds ratio [OR], 1.69) and early ARM (OR, 1.45). An increased risk of late AMD, but not early ARM, was associated with both high (OR, 2.54) and low (OR, 2.18) skin sun sensitivity, as assessed using the Fitzpatrick sun-sensitivity scale. These associations remained after adjusting for the presence of sun-related skin damage. Neither history (or treatment) of skin cancer lesions, signs of sun-induced skin damage, or number of severe sunburns was associated with either late AMD or early ARM. CONCLUSIONS: Blue iris color was associated with an increased risk of both late AMD and early ARM in this population. Abnormal skin sensitivity to sunlight was also associated with an increased risk of late AMD.

Cross-Sectional Studies↗
PubMed2000

Metals and arsenic in eye shadows.

The regulations relating to cosmetic products give no limit values for toxic elements such as metals or arsenic occurring as impurities in cosmetic products. The present study of metals (lead, cobalt, nickel, chromium) and arsenic in eye shadows in 88 colors of 25 brands and 49 products provides a basis for assessing the safety of eye shadow. 66 out of 88 (75%) of the colors contained more than 5 ppm of at least one of the elements, and all 49 products contained more than one 1 ppm of at least 1 of the elements. In one color, the amount of all elements was less than 1 ppm. The highest levels of cobalt and nickel were 41 and 49 ppm, respectively. These levels were high enough to cause allergic symptoms in those previously sensitized. Furthermore, long-term exposure to such levels may probably sensitize. The concentrations of arsenic were extremely low, 2.3 ppm at most. The level of lead was less than 20 ppm in all products. Accordingly, the concentrations of arsenic and lead seemed to be safe. 9 colors had concentrations of water-soluble chromium exceeding 2 ppm, and a very high level, 318 ppm, was encountered in 1 case. The overall results indicate that eye-shadows probably have no significant systemic toxicological effects. The groups at greatest risk are those already sensitized to the allergenic elements. Such consumers will have difficulties in choosing suitable products, since these elements in the form of impurities are not declared in the list of ingredients. Manufacturers should demand certification that the raw materials they buy contain no toxic elements. Although some of the products studied were acceptable, many had excessive levels of the elements from the consumer's viewpoint.

Arsenic↗
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↗
PubMed1978

[Lens caused shifts in color co-ordinates measured on the ocular fundus (author's transl)].

Changes in certain areas of the ocular fundus are frequently accompanied by changes in the spectral distribution of the reflected light. In many diseases of the ocular fundus, it is desirable to have an objective difinition of the color of the fundus during a particular phase of the disease. An instrument designed by Carl Zeiss, Oberkochen, West Germany, provides a satisfactory solution to the problem of measuring color on the ocular fundus. Transformational equations make it possible to convert the measurement parameters obtained by visual comparison into standardized color measurment values. The measurement error is slighter than necessary for clinical examinations. The possible influence of the ocular lens's own color on the color co-ordinates measured on the fundus was examined. Measurement of fundus color in three suitable situations showed no differences in color coordinates on the fundus between aphakic eyes of younger patients and eyes containing lenses. Incipient cataracts cause only a slight shift of the color co-ordinates. More marked cataracts cannot lead to erroneous interpretation of the measurement results, since measurement with this method is no longer technically possible in such cases.

Adolescent↗
PubMed2006

Neural basis for priming of pop-out during visual search revealed with fMRI.

Maljkovic and Nakayama first showed that visual search efficiency can be influenced by priming effects. Even "pop-out" targets (defined by unique color) are judged quicker if they appear at the same location and/or in the same color as on the preceding trial, in an unpredictable sequence. Here, we studied the potential neural correlates of such priming in human visual search using functional magnetic resonance imaging (fMRI). We found that repeating either the location or the color of a singleton target led to repetition suppression of blood oxygen level-dependent (BOLD) activity in brain regions traditionally linked with attentional control, including bilateral intraparietal sulci. This indicates that the attention system of the human brain can be "primed," in apparent analogy to repetition-suppression effects on activity in other neural systems. For repetition of target color but not location, we also found repetition suppression in inferior temporal areas that may be associated with color processing, whereas repetition of target location led to greater reduction of activation in contralateral inferior parietal and frontal areas, relative to color repetition. The frontal eye fields were also implicated, notably when both target properties (color and location) were repeated together, which also led to further BOLD decreases in anterior fusiform cortex not seen when either property was repeated alone. These findings reveal the neural correlates for priming of pop-out search, including commonalities, differences, and interactions between location and color repetition. fMRI repetition-suppression effects may arise in components of the attention network because these settle into a stable "attractor state" more readily when the same target property is repeated than when a different attentional state is required.

Adult↗
PubMed2005

[Color vision in glaucoma].

This article is a general view of evaluated acquired color vision defects in the early stages of primary glaucoma and in patients at risk for glaucoma. The articles published until now indicates a decrease in color discriminating sensitivity in the short wavelength part of the visible spectrum in patients with glaucoma as well as in patients with ocular hypertension. It has been found a positive correlation between the blue-yellow color vision defects and the perimetric changes in the glaucomatous eyes. Blue-yellow color vision testing with the anomaloscope may serve as an additional test in the early diagnosis of glaucoma but the absence of dyschromatopsia does not exclude the disease.

Color Perception↗
PubMed1990

Study of estimation of color recognition on the dentist. On the ability of subjects to discriminate color in terms of hue, value and chroma.

The tooth crown color space model was manufactured and the improvement of the color representation and communication on the dental clinic have been trying. The study of color discrimination by dentist and student viewing with the use of tooth crown color chips reported here in basic knowledge on the color sensitivity of human eye. The test card were 55 x 90 mm in size and the color chip, 5 x 10 mm. The paired color chips were placed on the test card to have a 2 mm distance between them. Color difference of two tooth crown color chips on the test cards was 3.5 (delta E*ab), the combination of hue, value and chroma was constant of all cards. The subjects were 22 people, 6 dentists and 16 dental school students with normal color sensibility. In proportion of method of comparison for surface color (JIS Z 8723), the subject observed the test card which were different of hue, value and chroma on the their naked-eye, were investigated to evaluate their judgement of the test cards. The following results were obtained. The standard of judgment for the color discrimination was made firstly in terms of hue, secondly in terms of value, and thirdly in terms of chroma.

Adult↗