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PubMed2001

Colour discrimination impairment is not a reliable early marker of Parkinson's disease.

Disturbances of colour visual discrimination have been shown to occur frequently in Parkinson's disease (PD). To verify the potential utility of reduced colour sensitivity as a diagnostic marker of early PD, we examined 14 PD patients, mean age 55.4 years, disease duration 2.3 years, in Hoehn and Yahr stages 1, 1.5, or 2, previously untreated with levodopa. Colour discrimination was measured with the Farnsworth-Munsell 100-hue test in patients who were compared with age-matched controls. The examinations were performed under standard conditions in a room illuminated by a daylight lamp Biolux Osram 6500 K. The mean total error score (MTES) and partial error scores (green-yellow and red-green axis) were calculated for every person examined. No significant differences were found between PD patients (MTES 49.1 +/- SD 37) and controls (MTES 37.9 +/- SD 25). Similarly, the mean partial scores were not significantly elevated in PD patients. We found an elevation of error scores exceeding the upper limit of normality (control mean + 2SD) only in three patients. We conclude that colour visual discrimination is not consistently impaired in early stages of PD and does not appear as a reliable early marker of Parkinson's disease.

Adult↗

PubMed2004

Colour vision and occupational toluene exposure: results of repeated examinations.

Potential effects of human occupational exposures to toluene on colour vision were investigated in a follow-up study over 4 years with three repeated examinations. Colour vision was measured with the Lanthony desaturated colour vision test D-15d, and the colour confusion index (CCI) was calculated. The mean current exposures were 26+/-21 ppm for printers (high toluene level) and 3+/-4 ppm for end-processors (low toluene level). The mean exposure durations were 23+/-6 years for "long-time exposed" and 7+/-2 years for "short-time exposed" subjects. Repeated analyses (n=162) and multiple regressions (maximum available n=267) did not reveal significant effects of toluene with respect to intensity or duration of current or long-term exposure. Age and occupational qualification were significantly associated with CCI in both kinds of analysis, whereas alcohol consumption (carbohydrate-deficient transferrin, CDT) and smoking habits (cigarettes per day) were not. It is concluded that current industrial exposure limits of toluene provide sufficient protection against possible disturbance of colour vision.

Adult↗

PubMed2001

Chromatic contrast thresholds as a prognostic test for visual improvement after macular hole surgery: color vision and macular hole surgery outcome.

PURPOSE: To evaluate the relationship between preoperative chromatic contrast thresholds, postoperative visual acuities (VA), and visual improvement after macular hole surgery. METHODS: A consecutive series of patients with Stage II to IV macular holes was studied before macular hole surgery. Preoperative chromatic contrast thresholds, VA, and reading acuity were analyzed in relation to the postoperative visual function. The chromatic contrast thresholds were measured using a computerized cathode ray tube-based system along red-green and tritan confusion axes. RESULTS: Preoperative and postoperative chromatic contrast thresholds were elevated significantly in affected eyes (P < 0.001). Preoperative VA showed a strong correlation with postoperative VA (r = 0.66, P < 0.001) but a weak correlation with visual improvement (r = -0.33, P = 0.03). Red-green contrast threshold correlated strongly with both the distance visual improvement (r = -0.77, P < 0.001) and reading visual improvement (r = -0.61, P < 0.001). Tritan contrast threshold, however, showed a slightly weaker correlation (distance: r = -0.63, P < 0.001; reading: r = -0.47, P < 0.005). CONCLUSIONS: These results suggest that chromatic contrast thresholds, especially the red-green contrast threshold, represent a better prognostic guide for visual improvement after macular hole surgery than VA measurement.

Aged↗

PubMed1991

Correlation of retinal nerve-fiber-layer loss, changes at the optic nerve head and various psychophysical criteria in glaucoma.

In 61 eyes of 61 patients with glaucoma, semiquantitative assessment of retinal nerve-fiber-layer (RNFL) loss and neuroretinal rim measurement of the optic nerve head by means of the Optic Nerve Head Analyzer were correlated to the outcomes of automated light-sense, flicker and resolution perimetry and the Farnsworth-Munsell (FM) 100-Hue test. A significant influence of age on total RNFL and total diffuse RNFL scores was found, but there was no measurable effect of age on neuroretinal rim area. Total RNFL and total diffuse RNFL scores showed a good correlation to the various visual field indices: total RNFL score vs mean flicker frequency as determined by flicker perimetry, r = -0.606, P less than 0.0001; total RNFL score vs mean sensitivity as determined by light-sense perimetry, r = -0.385, P = 0.002; and total RNFL score vs mean ring score as determined by resolution perimetry, r = 0.341, P = 0.007. There was no significant correlation between RNFL scores and the FM 100-Hue score. Correlation between the neuroretinal rim area and the various psychophysical indices was poor and mostly not statistically significant. The high correlation of flicker scores with RNFL loss provides interest for future applications of this perimetric technique.

Adult↗

PubMed1999

Assessment of potential macular function using a color saturation discrimination test in eyes with cataract.

PURPOSE: To study the efficacy of a color saturation discrimination test (CSDT) in assessing potential macular function in eyes with cataract. SETTING: Yamanashi Medical University and Nirasaki City Hospital, Yamanashi, Japan. METHODS: In this prospective study of 200 consecutive eyes with cataract, the thresholds of color saturation discrimination on 6 hues were measured with the CSDT. The CSDT program was run on a personal computer and cathode-ray tube color monitor. The preoperative CSDT scores and postoperative visual acuities were compared. In addition, preoperative laser interferometry (LI) and postoperative CSDT were performed on selected patients and the results compared with their preoperative CSDT results. RESULTS: Patients who had a CSDT score of 11 or more had a significantly lower postoperative visual acuity (P < .0001). The prevalence of neuroretinal abnormality postoperatively increased with the preoperative CSDT score. The CSDT score was not correlated with preoperative visual acuity (P = 1409). Cataract severity had little influence on the CSDT score. The preoperative results of the CSDT and Ll were correlated with the postoperative acuity, with the correlation coefficient being stronger with the CSDT (r = -0.338 and 0.276 for CSDT and Ll, respectively). CONCLUSION: The CSDT was effective in evaluating neuroretinal pathology and predicting postoperative acuity.

Cataract↗

PubMed2001

Distant cancer effects on standardised testing of peripheral vision.

BACKGROUND: Profound central-retinal visual losses have been a major presenting factor reported in cancer and melanoma associated retinopathies (CAR, MAR). However, it is well established that standardised tests of peripheral retinal function are often the most sensitive detectors of early eye disease. This is a preliminary investigation of the responsiveness of the peripheral retina to "distant" (non-eye or CNS) cancers using easily obtained standardised tests. METHODS: The design is a single blind study where test results are compared with published norms and a small age matched control group. Of 120 ambulatory cancer outpatients who were interviewed at routine follow up examinations, 111 volunteered and admitted a range of mild visual changes. 25 cancer patients completed all tests of peripheral vision function and a clinical screening. There were seven control subjects of the same age range. RESULTS: 98% (49 of 50) of eyes from the patient cohort were judged clinically normal following examinations which emphasised the central retina, fundus appearance, and static fields. On testing which emphasised the visual periphery, 46 (92%) eyes showed one or more quantitative abnormalities >2 SD from the age adjusted norm means. These abnormalities clustered mainly about dark adaptation (rod cell) sensitivity (31, 62% of measured sites), the blue sensitive retinal cells (17, 34% of measured eyes), and the oscillatory component (OP) of the electroretinogram (23, 46% of measured eyes). One control eye (7%) showed a significant dark adaptation abnormality and ERG reduction. There was no identifiable interaction between chemotherapy mode and the cancer associated retinal deficits (CARD). Antiretinal antibodies were found in sera from most patients and controls. CONCLUSION: CARD is common in the retinal periphery of many cancer patients, and is distinct from rare CAR, MAR central-retinal responses. CARD has numerous potential clinical uses which justify expanded research with more defined large samples.

Adaptation, Ocular↗

PubMed1987

Assessing color vision loss among solvent-exposed workers.

Acquired color vision loss has been associated with exposure to organic solvents in the workplace. However, not all tests of chromatic discrimination loss are designed to detect acquired, as opposed to congenital, loss. The Lanthony D-15 desaturated panel (D-15-d), a simple 15 cap color arrangement test, designed to identify mild acquired dyschromatopsia, can be administered rapidly in the field, under standard conditions. The objective of the present study was to evaluate the D-15-d among 23 solvent-exposed workers of a paint manufacturing plant, by comparing the results obtained with the D-15-d to those obtained with the Farnsworth-Munsell 100 Hue (FM-100), a highly sensitive measure of color vision loss. The D-15-d revealed a significantly higher prevalence of dyschromatopsia among the ten highly exposed workers (80%) as compared to the 13 moderately exposed workers (30.8%); FM-100 results revealed one false positive. All dyschromatopic workers presented blue-yellow loss; the FM-100 detected eight complex patterns, while the D-15-d identified 5. Comparison of D-15-d and FM-100 scores were highly correlated (corr. coeff. 0.87; p less than 0.001). Multiple regression analyses showed both scores to be significantly related to age and exposure level. The findings of this study indicate that the D-15-d is an adequate instrument for field study batteries. However, the FM-100 should be used for more detailed assessment.

Color Perception↗

PubMed1995

[Evaluation of the desaturated Panel D-15. IV. Effect of the repetition of desaturated Panel D-15].

PURPOSE: The desaturated Panel D-15 was performed in a repetitive manner to determine whether such repetition improves test results, and, specially, whether repetition can eliminate false positives. METHODS: The study population included 100 subjects with normal colour vision. The experimental procedure included: first the standard Farnsworth's Panel D-15 test, then the desaturated Panel D-15 test performed three times consecutively by each subject. Qualitative evaluation with the Farnsworth D-15 classical diagram and quantitative evaluation with scores calibrated according to the ages of the subjects were used. RESULTS: The standard Panel D-15, performed first, was of no predictive value for the subsequent desaturated Panel D-15 (Cohen's K = 0.08). The desaturated Panel D-15 performed three times consecutively gave evidence of improvement in all the studied variables, from the first to the third time: scores tended toward low values, lower mean score (from 85 to 42); more zero scores (from 17 to 32); smaller number of abnormal scores (from 16 to 3). At the first performance of the desaturated Panel D-15, there were 16% false positives. At the second, there were 3%; and at the third, none of the initial false positives occurred. CONCLUSION: Three successive performances of the desaturated Panel D-15 were necessary and sufficient to eliminate all false positives and can also assess some abnormal results.

Adolescent↗

PubMed2002

Short-wavelength sensitivity deficits in patients with migraine.

OBJECTIVE: To examine short-wavelength sensitivity in patients with migraine using short-wavelength automated perimetry (SWAP) and Stiles 2-color increment threshold procedures. METHODS: Twenty-five subjects with migraine with (n = 11) and without (n = 14) aura and 20 age-matched headache-free subjects underwent testing. All subjects underwent standard automated perimetry (SAP) and SWAP (using a Humphrey field analyzer; 24-2 presentation pattern). In 2 migraine patients (one with and another without aura), the 2-color increment threshold procedure was used to determine whether sensitivity losses were specific to short-wavelength sensitivity pathways or a generalized loss to multiple pathways. RESULTS: No statistically significant differences between migraine patients and controls were found for mean deviation (MD) or pattern-standard deviation (PSD) for SAP. However, for SWAP, MD and PSD were worse for the migraine group (P =.04). Twelve migraine patients had more than 4 locations with sensitivity worse than the 5% probability level (reference value). Increment threshold determinations in the 2 selected migraine patients indicated a selectively greater loss for short-wavelength sensitivity mechanisms. CONCLUSIONS: Approximately 50% of subjects with migraine (with or without aura) demonstrate SWAP sensitivity losses, at times between migraine events. These findings, in conjunction with previous results for SAP and flicker perimetry, suggest that migraine patients should be excluded from normative databases of visual function, and warrant further investigations of the relationship between migraine and glaucoma.

Adolescent↗

PubMed1996

The variable expressivity of a family with central areolar pigment epithelial dystrophy.

PURPOSE: To clarify the nosology of autosomal dominant central areolar pigment epithelial dystrophy (CAPED) as previously described. METHODS: The authors studied a family of 69 members spanning six generations with a macular dystrophy. Thirty-four patients were examined, and those found to be affected underwent further testing, including visual fields, electrophysiologic studies, and fluorescein angiography. Family history and medical records were used in three additional deceased patients. RESULTS: Eleven patients were identified as having CAPED. The phenotype was inherited in an autosomal dominant fashion. Six of these patients were examined by us and had mid-life onset (at 32-53 years) of progressive visual loss (20/50--counting fingers), occurring over a 3- to 10-year period. These subjects had circumscribed hypopigmented maculae, retinal pigment epithelial window defects on fluorescein angiography, central scotomas, and electrophysiologic studies, ranging from normal to severely abnormal. Three deceased patients were presumed to have CAPED by review of records or family history. Two additional patients examined had mild macular changes but good visual acuity and no significant abnormalities on electrophysiologic studies. The latter two patients are presumed to have had early manifestations of CAPED. CONCLUSION: This family demonstrates that CAPED is an autosomal-dominant hereditary macular dystrophy which has late-onset and variable expressivity.

Adult↗

PubMed2004

Peripheral cone dystrophy: a variant of cone dystrophy with predominant dysfunction in the peripheral cone system.

PURPOSE: To determine the phenotype of 3 patients from 2 pedigrees with an unusual form of cone dystrophy in which the peripheral cone system is more affected than the central cone system, and whose rod system is relatively normal. DESIGN: Three observational case reports with electrophysiologic and psychophysical studies. METHODS: Three patients underwent fundus photography, fluorescein angiography, color vision testing, Goldmann visual field testing, full-field electroretinograms (ERGs), focal macular cone ERGs, and rod-cone perimetry, in addition to routine ophthalmologic examinations. Multifocal ERGs also were recorded from 2 patients. RESULTS: The fundus examination and fluorescein angiogram results essentially were normal except for a mild temporal pallor of the optic disc in 2 patients. The corrected visual acuity ranged from 20/16 to 20/100. Color vision was normal in 1 patient, but was abnormal in 2 patients. A relative paracentral scotoma was detected in 2 patients. Full-field ERG cone responses were reduced significantly, but rod responses were normal in all patients, as in patients with typical cone dystrophy. However, the focal macular cone ERGs were well preserved in all patients. Psychophysical rod-cone perimetry demonstrated that the peripheral cone system was impaired, whereas the rod sensitivity was completely normal. The results of the multifocal ERG in 2 patients supported the findings made by the full-field and focal macular ERGs. CONCLUSIONS: These findings demonstrate that there is a subgroup of patients with cone dystrophy where the peripheral cone system is more affected than the central cone system.

Adult↗

PubMed2006

Combining local and global contributions to perceived colour: an analysis of the variability in symmetric and asymmetric colour matching.

Are surfaces' colours judged from weighted averages of the light that they reflect to the eyes and the colour contrast at their borders? To find out we asked subjects to set the colour and luminance of test disks to match reference disks, on various backgrounds, and analysed the variability in their settings. Most of the variability between repeated settings was in luminance. The standard deviations in the set colour were smallest when the disk and background were the same colour, irrespective of the colour itself. Matches were equally precise for greenish or reddish disks on a grey background, as for grey disks on a greenish or reddish background. The precision was less dependent on the colour contrast at the disks' borders when the backgrounds were more complex and when there was a large luminance contrast at the disks' borders. Subjects were less precise when different colours surrounded the two disks. These findings are consistent with the perceived colour at any position being a weighted average of the local cone excitation ratio and the change in the cone excitation ratio at the borders of the surface in question. However, the involved weights must be variable and depend systematically on parameters such as the luminance contrast at the surface's borders and other chromatic contrasts within the scene.

Color Perception↗

PubMed1990

Evaluation of patients with obvious or suspected degenerative and dystrophic disorders of the retina, pigment epithelium and choroid. Experience from a Swedish referral center.

Between August 1, 1982, and December 31, 1988, 487 patients with clinically established or suspected diagnosis of a hereditary degenerative or dystrophic disorder of the ocular fundus or of a disorder of the optic pathways were evaluated with an extensive set of clinical and electrophysiological tests, 67% of the patients were referred from other eye departments. In order of magnitude the most frequently encountered diagnoses were: 1) 'functional' disturbances (18%), 2) disorders of the optic nerve (9%), 3) retinitis pigmentosa (8%), 4), 5) and 6) progressive cone dystrophy, disorders of the central optic pathways, and fundus flavimaculatus/Stargardt's disease (5% each), and 7) choriocapillaris atrophy (4%). Choriocapillaris atrophy affected older patients than retinitis pigmentosa (P less than 0.001). A male preponderance was observed for juvenile retinoschisis (P less than 0.005) and congenital stationary night blindness (P less than 0.05), and a female dominance in the groups of patients with 'functional' symptoms (P less than 0.01). A specific diagnosis was established in 469 patients. After exclusion of 16 patients referred because of a known hereditary disposition, 196 (43%) of the remaining 453 patients were referred under the same diagnosis as our final diagnosis, 153 (34%) under a different diagnosis and 104 (23%) without any clear diagnosis. Obviously, there is a need for regional centers specialized in these disorders.

Adolescent↗

PubMed2005

Increasing reading speed by using colours: issues concerning reliability and specificity, and their theoretical and practical implications.

By using techniques for precision ophthalmic tinting, individuals who report perceptual distortion of text can often find a colour of illumination that eliminates the distortions and increases reading speed. Most individuals choose green or blue hues, but there is considerable variability. We investigated how specific the colour has to be to obtain optimal reading speed. Individuals who habitually wear coloured filters for reading were asked to read text illuminated by coloured light (without using their filters). Reading speed was measured repeatedly with light of different colours. The colour (chromaticity) at which reading was fastest was consistent from one test session to the next. It was different from one individual to another, but highly specific for each individual: departures of colour from optimum by about 6 JNDs eliminated most of the speed advantage conferred by the optimal colour. It was difficult to attribute the consistency and specificity simply to familiarity with the tint or immediate memory for the colour of illumination. A consecutive sample of 1000 tint prescriptions was analysed numerically. For most prescriptions the variation in chromaticity with different types of lighting was not such as to remove all the potential benefit of the tint, as judged from a model of the effect of chromaticity on reading speed. The exceptions were the few tints that were weakly saturated or purple in colour. Across participants, reading speed was not consistently related to the scotopic energy, to the energy captured by any cone class, or to opponent colour processes. The reading was generally slowest with white light, and not with the colour complementary to the optimum. Explanations in terms of magnocellular deficits and cortical hyperexcitability are briefly discussed.

Adolescent↗

PubMed1994

Effects of lorazepam on cardiac vagal tone during rest and mental stress: assessment by means of spectral analysis.

Dose-dependent effects of intravenously administered lorazepam on haemodynamic fluctuations were studied by means of spectral analysis, in order to elucidate sympathetic and parasympathetic components in cardiovascular control during situations of rest and mental stress after benzodiazepine administration. In a double-blind randomized cross-over study, nine male volunteers participated in two sessions: a placebo and lorazepam session. During these sessions, the subjects repeatedly performed a 10-min version of the Stroop Color Word Test (CWT), with 10 min of rest between the CWTs. Lorazepam was administered before each rest period in increasing doses of 0.0, 0.06, 0.13, 0.25 and 0.5 mg (total cumulative dose: 0.94 mg). During the placebo session the subjects received five placebo injections. For five of the nine subjects the lorazepam session was their first session. Heat rate (HR), blood pressure (BP) and respiration were recorded continuously. Power spectra were calculated per 2.5-min periods for HR, systolic (SBP) and diastolic BP (DBP). Spectral density was assessed for three frequency bands: low (LFB: 0.02-0.06 Hz), mid (MFB: 0.07-0.14 Hz) and high (HFB: 0.15-0.40 Hz). During the consecutive periods of rest, lorazepam induced a dose-dependent decrease in HR, and a dose-dependent increase in LFB, MFB and HFB power of HR, but lorazepam had no effect on BP. The effects were significant after 0.44 mg lorazepam for HR and HFB power, and after 0.94 mg lorazepam for the HR fluctuations in the LFB and MFB. Lorazepam did not influence the cardiovascular responses to the CWT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Color changes in the red-green plates of the 50-year-old AO HRR color vision test.

The original AO HRR color vision test has been considered by many as one of the best plate tests. It is still accepted by many governmental agencies for color vision certification. In their 1954 publication, Hardy, Rand, and Rittler stated that specially compounded inks were used for printing to avoid color changes with time. Fifty years later, it is both important and interesting to determine whether the wear and tear cause significant color changes. The chance finding of a never-used second edition offers an opportunity to evaluate the color changes. A GretagMacbeth Spectrolino spectrophotometer was used to measure the chromaticities of the never-used book, and an extensively used book. Four plates (#4, 7, 13, 16), selected randomly from the four red-green sections, were analyzed. The colored dots from each of the eight plates were plotted on a CIE chromaticity diagram. Isocolor lines were drawn to evaluate chromatic alignment. Chromaticities for plates #4 and 7 are significantly different between the two books. With regard to alignment with isocolor lines, the extensively used book is better than the never-used book for plate #4. There is significant misalignment on plate #7 for both books. Chromaticities for plates #13 and 16 are essentially identical between books, all with good alignment with isocolor lines. The overall comparison shows that the chromatic alignment characteristics of the extensively used book are not worse than the never-used book. Since colors in these plates have to be aligned with both the protan and deutan axes, any significant color changes would have disturbed this delicate requirement. The findings of many plates with good alignment, and the lack of differences on plates #13 and 16 between books, suggest that there are no significant color changes over time. Differences between books on plates #4 and 7 were likely the result of the original printing process.

Color↗

PubMed1993

Investigations of the functional anatomy of attention using the Stroop test.

In two separate experiments positron emission tomography (PET) was used to measure changes in regional cerebral blood flow while normal subjects performed the Stroop colour word interference test, a test of selective attention. In the first experiment performance of the Stroop task was associated with activation of right orbito-frontal and bilateral parietal structures, an unexpected result in view of previously reported findings. In addition, there were highly significant time related focal changes in rCBF. A second experiment was therefore carried out which altered the experimental parameters to replicate an earlier study. In this second experiment focal activation of the right anterior cingulate and right frontal polar cortex occurred during the Stroop task. As in the first experiment significant time effects were again apparent. To determine the functionally related brain systems during the performance of the Stroop task a correlation analysis was carried out in relation to blood flow changes induced by experimental manipulation in the right anterior cingulate. This analysis indicated the engagement of a widespread network of anterior brain regions and reciprocal inhibition of posterior brain regions during the performance of the task. The results provide evidence for the involvement of anterior right hemisphere and medial frontal structures in attentional tasks but also indicate that time effects can confound task specific activations. Furthermore subtle experimental treatment parameters, such as stimulus presentation rate, influence the degree and distribution of observed activations.

Adult↗

PubMed2006

Cone contributions to signals for accommodation and the relationship to refractive error.

The accommodation response is sensitive to the chromatic properties of the stimulus, a sensitivity presumed to be related to making use of the longitudinal chromatic aberration of the eye to decode the sign of the defocus. Thus, the relative sensitivity to the long- (L) and middle-wavelength (M) cones may influence accommodation and may also be related to an individual's refractive error. Accommodation was measured continuously while subjects viewed a sine wave grating (2.2c/d) that had different cone contrast ratios. Seven conditions tested loci that form a circle with equal vector length (0.27) at 0, 22.5, 45, 67.5, 90, 120, 145 deg. An eighth condition produced an empty field stimulus (CIE (x,y) co-ordinates (0.4554, 0.3835)). Each of the gratings moved at 0.2 Hz sinusoidally between 1.00 D and 3.00 D for 40s, while the effects of longitudinal chromatic aberration were neutralized with an achromatizing lens. Both the mean level of accommodation and the gain of the accommodative response, to sinusoidal movements of the stimulus, depended on the relative L and M cone sensitivity: Individuals more sensitive to L-cone stimulation showed a higher level of accommodation (p=0.01; F=12.05; ANOVA) and dynamic gain was higher for gratings with relatively more L-cone contrast. Refractive error showed a similar correlation: More myopic individuals showed a higher mean level of accommodation (p<0.01; F=11.42; ANOVA) and showed higher gain for gratings with relatively more L-cone than M-cone contrast (p=0.01; F=10.83 ANOVA). If luminance contrast is maximized by accommodation, long wavelengths will be imaged behind the photoreceptors. Individuals in whom luminance is dominated by L-cones may maximize luminance contrast both by accommodating more, as shown here, and by increased ocular elongation, resulting in myopia, possibly explaining the correlations reported here among relative L/M-cone sensitivity, refractive error and accommodation.

Accommodation, Ocular↗