Left OFC Activation in Functional Near-Infrared Spectroscopy during an Inhibitory Control Task in an Early Years Sample: Integrating Stress Responses with Cognitive Function and Brain Activation.

INTRODUCTION: Previous functional near-infrared spectroscopy (fNIRS) studies using Go/No-Go (GNG) tasks have focused on brain activation in relation to cognitive processes, particularly inhibitory control (IC). The results of these studies commonly describe right hemispheric engagement of the dorsolateral, ventromedial, or inferior frontal regions of the prefrontal cortex. Considering that typical healthy cognitive development is negatively correlated with higher cortisol levels (which may alter brain development), the overarching aim of the current study was to investigate how elevated stress (due to unforeseeable events such as the pandemic) impacts early cognitive development. METHOD: In this study, we examined fNIRS data collected from a sample of children (aged 2-4 years) during a GNG task relative to the response to stressors measured via hair cortisol concentrations. We acquired data in an ecological setting (Early Childhood Education and Care) during the coronavirus pandemic. RESULTS: We found that children with higher stress levels and a less efficient IC recruited more neural terrain and our group-level analysis indicated activation in the left orbitofrontal area during IC performance. CONCLUSIONS: A contextual stressor may disrupt accuracy in the executive function of IC early in development. More research efforts are needed to understand better how an orbitofrontal network subserves goal-directed behavior.

Olfactory interference on the emotional processing speed of visual stimuli: The influence of facial expressions intensities.

Research on olfactory stimulation indicates that it can influence human cognition and behavior, as in the perception of facial expressions. Odors can facilitate or impair the identification of facial expressions, and apparently its hedonic valence plays an important role. However, it was also demonstrated that the presentation of happiness and disgust faces can influence the emotional appraisal of odorants, indicating a bilateral influence in this phenomenon. Hence, it's possible that odor influences on emotional categorization vary depending on the intensity of expressions. To investigate this hypothesis, we performed an emotion recognition task using facial expressions of five emotional categories (happiness, fear, disgust, anger and sadness) with ten different intensities. Thirty-five participants completed four blocks of the task, each with a different olfactory condition, and we found that odorants' effects varied according to the facial expressions intensity. Odorants enhanced the Reaction Time (RT) differences between threshold and high-intensity expressions for disgust and fear faces. Also, analysis of the RT means for high-intensity facial expressions revealed that the well-known advantage in recognition of happiness facial expressions, compared to other emotions, was enhanced in the positive olfactory stimulation and decreased in the negative condition. We conclude that olfactory influences on emotional processing of facial expressions vary along intensities of the latter, and the discrepancies of past research in this field may be a result of a bilateral effect in which the odorants influence the identification of emotional faces just as the facial expressions influence the emotional reaction to the odor.

The impacts of abnormal color vision on people's life: an integrative review.

BACKGROUND: This article shows an integrative review on the impact that abnormal color vision may have on the daily routine of individuals. PURPOSE: We followed the PRISMA guidelines for reviews and carried out researches in four databases (Pubmed, Lilacs, Scopus, and Web of Science) using keywords related to the impact of abnormal color vision. METHOD: Initially, 805 articles were retrieved and after a first filtering stage, we selected 74 articles for a detailed analysis of the abstracts in which it was found that a total of 20 studies were in fact related to the topic of this review. We then read the selected studies in full and those included in the final selection were analyzed and categorized into specific topic groups of findings. Seven categories were created in total: "impact on daily routine activities", "occupational impact", "impact on product choice motivation", "emotional impact", "impact on school or professional qualification", "impact on self-care and health", and "advantages". RESULTS: From the definition of these categories we could understand that people with some degree of color vision loss face challenges in different aspects of their daily life, especially in their work activities. Still, the amount of research and hence technical support which could be offered to this population is restricted. Additionally, the scarce availability of publications on the topic and the fact that they include very specific groups of people, such as drivers and medical students, allow us to draw only partial conclusions about the all possible impacts yield by such perceptual difference since they observe the impact of the color-vision deficiency in their daily routine from a specific and precise point of view. CONCLUSIONS: A broader view of the impact of this problem on the daily life of its carriers is fundamental for implementing strategies that allow such people to be included in all sorts of activities or for the impact of this sensory change to be decreased or treated in a way that would reduce the detrimental impacts.

Contrasting effects of transcranial direct current stimulation on central and peripheral visual fields.

Recent research suggested that transcranial direct current stimulation (tDCS) can affect visual processing and that it can be useful in visual rehabilitation. Nevertheless, there are still few investigations on the subject. tDCS selectivity and the extent of its outcomes on visual perception are still to be assessed. Here, we investigate whether central and peripheral visual fields are equally affected by tDCS. We also tried to reproduce a previous work that has evaluated tDCS effects on the central visual field only (Kraft et al. 207:283-290, 2010). Fifteen healthy subjects participated in this randomized repeated-measure design study and received 1.5-mA anodal, cathodal and sham stimulation in different sessions, while performing 10-2 and 60-4 protocols in an automated perimeter. Anodal tDCS significantly decreased thresholds, but was limited to the most eccentric regions of the visual field measured (60°). This suggests that tDCS might be used for rehabilitation of peripheral visual field losses. We did not replicate the excitatory tDCS effect in the central visual field as previously reported by another group. Instead, we observed a trend toward an inhibitory (yet not statistically significant) effect of anodal tDCS on the central field. This might be explained by methodological differences. These results highlight that although tDCS is a technique with a low focality in the spatial domain, its effects might be highly focal in a functional domain. When taken together with previous findings, this also suggests that tDCS may have a differential effect on different retinotopic areas in the brain.

Transcranial direct current stimulation can selectively affect different processing channels in human visual cortex.

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that can modulate cortical activity. Nonetheless, information regarding its functional specificity and the extent by which visual performance can be modulated is still lacking. Here, we used vision as model to address if it differentially affects different cell groups in the stimulated area. We applied tDCS to the occiput and performed a series of visual tests in a sham-controlled repeated-measures design. Achromatic contrast sensitivity was assessed psychophysically during tDCS, with tasks designed to target specific spatial frequency (SF) channels, inferred ON, OFF channels and inferred magnocellular and parvocellular pathways of the visual system. Sweep visual evoked potential (sVEP) for contrast sensitivity and Vernier acuity was recorded before and after tDCS. Anodal tDCS significantly increased thresholds for luminance decrements (OFF) only for the inferred magnocellular thresholds. Although tDCS had no significant effects on Vernier or contrast sVEP thresholds, it modulated suprathreshold amplitudes for both tasks. Cathodal tDCS increased sVEP amplitudes at a low SF, decreased it at a medium, and had no effect at a high SF. Cathodal tDCS increased sVEP phase lags for low and decreased it for high SF (maximum change corresponding to change in apparent latency >6 ms). Cathodal and anodal stimulation decreased amplitudes of sVEP Vernier responses. Exclusive tDCS effects on magnocellular thresholds agree with reports of pathway-specific tDCS effects. The dependence of tDCS effects on SF and contrast levels further suggests that tDCS differentially affects different cell groups in the visual cortex.

Early visual changes in diabetic patients with no retinopathy measured by color discrimination and electroretinography

Early visual changes caused by diabetes include color vision losses and an abnormal full-field electroretinogram. The purpose of this study was to evaluate color vision in type 2 diabetic patients with no clinically detectable retinopathy using an objective psychophysical color vision test, evaluate retinal function assessed by full-field electroretinography (ffERG), and verify the agreement among the changes detected by each of these tests. Color vision was tested and ffERG was performed in 34 diabetic patients (20 males; ages 56 ± 9 years). Results were compared with those obtained from age-matched control groups. Color discrimination losses occurred in all three color-confusion axes with a higher incidence on the protan axis. The full-field electroretinographic data indicated that inner retinal components (i.e., ffERG oscillatory potentials) were more affected than outer retinal components, indicating impairment of second- and third-order retinal neurons early in the disease. Previous studies reported tritan losses as a classic color vision defect in diabetes, but our results showed that all three color-confusion axes (i.e., protan, deutan, and tritan) are compromised, at least during the very early stages of the disease, reflecting a diffuse pattern of color vision loss. The full-field electroretinographic results that showed abnormalities of the inner retina support the color vision findings...

Early visual changes in diabetic patients with no retinopathy measured by color discrimination and electroretinography

Early visual changes caused by diabetes include color vision losses and an abnormal full-field electroretinogram. The purpose of this study was to evaluate color vision in type 2 diabetic patients with no clinically detectable retinopathy using an objective psychophysical color vision test, evaluate retinal function assessed by full-field electroretinography (ffERG), and verify the agreement among the changes detected by each of these tests. Color vision was tested and ffERG was performed in 34 diabetic patients (20 males; ages 56 ± 9 years). Results were compared with those obtained from age-matched control groups. Color discrimination losses occurred in all three color-confusion axes with a higher incidence on the protan axis. The full-field electroretinographic data indicated that inner retinal components (i.e., ffERG oscillatory potentials) were more affected than outer retinal components, indicating impairment of second- and third-order retinal neurons early in the disease. Previous studies reported tritan losses as a classic color vision defect in diabetes, but our results showed that all three color-confusion axes (i.e., protan, deutan, and tritan) are compromised, at least during the very early stages of the disease, reflecting a diffuse pattern of color vision loss. The full-field electroretinographic results that showed abnormalities of the inner retina support the color vision findings.(AU)

Long-term occupational exposure to organic solvents affects color vision, contrast sensitivity and visual fields.

The purpose of this study was to evaluate the visual outcome of chronic occupational exposure to a mixture of organic solvents by measuring color discrimination, achromatic contrast sensitivity and visual fields in a group of gas station workers. We tested 25 workers (20 males) and 25 controls with no history of chronic exposure to solvents (10 males). All participants had normal ophthalmologic exams. Subjects had worked in gas stations on an average of 9.6 ± 6.2 years. Color vision was evaluated with the Lanthony D15d and Cambridge Colour Test (CCT). Visual field assessment consisted of white-on-white 24-2 automatic perimetry (Humphrey II-750i). Contrast sensitivity was measured for sinusoidal gratings of 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 and 20.0 cycles per degree (cpd). Results from both groups were compared using the Mann-Whitney U test. The number of errors in the D15d was higher for workers relative to controls (p<0.01). Their CCT color discrimination thresholds were elevated compared to the control group along the protan, deutan and tritan confusion axes (p<0.01), and their ellipse area and ellipticity were higher (p<0.01). Genetic analysis of subjects with very elevated color discrimination thresholds excluded congenital causes for the visual losses. Automated perimetry thresholds showed elevation in the 9°, 15° and 21° of eccentricity (p<0.01) and in MD and PSD indexes (p<0.01). Contrast sensitivity losses were found for all spatial frequencies measured (p<0.01) except for 0.5 cpd. Significant correlation was found between previous working years and deutan axis thresholds (rho = 0.59; p<0.05), indexes of the Lanthony D15d (rho=0.52; p<0.05), perimetry results in the fovea (rho= -0.51; p<0.05) and at 3, 9 and 15 degrees of eccentricity (rho= -0.46; p<0.05). Extensive and diffuse visual changes were found, suggesting that specific occupational limits should be created.

Contrast sensitivity mediated by inferred magno- and parvocellular pathways in type 2 diabetics with and without nonproliferative retinopathy.

PURPOSE: To evaluate achromatic contrast sensitivity (CS) with magnocellular- (M) and parvocellular- (P) probing stimuli in type 2 diabetics, with (DR) or without (NDR) nonproliferative retinopathy. METHODS: Inferred M- and P-dominated responses were assessed with a modified version of the steady-/pulsed-pedestal paradigm (SP/PP) applied in 26 NDR (11 male; mean age, 55 ± 9 years; disease duration, 5 ± 4 years); 19 DR (6 male; mean age, 58 ± 7 years; disease duration = 9 ± 6 years); and 18 controls (CTRL; 12 male; mean age, 55 ± 10 years). Thresholds were measured with pedestals at 7, 12, and 19 cd/m(2), and increment durations of 17 and 133 ms. The thresholds from the two stimulus durations were used to estimate critical durations (Tc) for each data set. RESULTS: Both DR and NDR patients had significant reduction in CS in both SP and PP paradigms in relation to CTRL (Kruskal-Wallis, P < 0.01). Patients' critical duration estimates for either paradigm were not significantly different from CTRL. CONCLUSIONS: The significant reduction of CS in both paradigms is consistent with losses of CS in both M and P pathways. The CS losses were not accompanied by losses in temporal processing speed in either diabetic group. Significant CS loss in the group without retinopathy reinforces the notion that neural changes associated with the cellular and functional visual loss may play an important role in the etiology of diabetic visual impairment. In addition, the results show that the SP/PP paradigm provides an additional tool for detection and characterization of the early functional damage due to diabetes.

Color vision impairment in type 2 diabetes assessed by the D-15d test and the Cambridge Colour Test.

Color vision impairment emerges at early stages of diabetes mellitus type 2 (DM2) and may precede diabetic retinopathy or the appearance of vascular alterations in the retina. The aim of the present study was to compare the evaluation of the color vision with two different tests - the Lanthony desaturated D-15d test (a traditional color arrangement test), and the Cambridge Colour Test (CCT) (a computerized color discrimination test) - in patients diagnosed with DM2 without clinical signs of diabetic retinopathy (DR), and in sex- and age-matched control groups. Both color tests revealed statistically significant differences between the controls and the worst eyes of the DM2 patients. In addition, the degree of color vision impairment diagnosed by both tests correlated with the disease duration. The D-15d outcomes indicated solely tritan losses. In comparison, CCT outcomes revealed diffuse losses in color discrimination: 13.3% for best eyes and 29% for worst eyes. In addition, elevation of tritan thresholds in the DM2 patients, as detected by the Trivector subtest of the CCT, was found to correlate with the level of glycated hemoglobin. Outcomes of both tests confirm that subclinical losses of color vision are present in DM2 patients at an early stage of the disease, prior to signs of retinopathy. Considering the advantages of the CCT test compared to the D-15d test, further studies should attempt to verify and/or improve the efficiency of the CCT test.

Avaliação funcional da visão de pacientes diabéticos em estados pré e pós retinopatia diabética / Functional visual assessment in diabetic patients at stages pre- and post- diabetic retinopathy

O presente estudo avaliou diferentes aspectos funcionais da visão de diabéticos do tipo 2 com e sem retinopatia diabética. A visão desses pacientes foi avaliada em diferentes níveis do sistema visual por meio da aplicação de uma bateria de testes psicofísicos e eletrofisiológicos de grande sensibilidade. O objetivo foi caracterizar as alterações visuais provocadas pela doença antes do aparecimento de retinopatia, e avaliar o efeito da presença da retinopatia sobre as alterações funcionais precoces. Materiais e métodos: 31 pacientes diabéticos com retinopatia não proliferativa leve (15 , 16 ; idade = 59 ± 09; tempo de diabetes = 10 ± 06 anos); 36 pacientes diabéticos sem retinopatia (16 , 20 idade = 56 ± 11; tempo de diabetes = 06 ± 04 anos) e 30 sujeitos controle (13 , 17 ; idade = 44 ± 10 anos) foram submetidos a exames de (1) eletrorretinograma multifocal - mfERG; (2) sensibilidade ao contraste acromático segregada em componentes magno (MC) e parvocelulares (PC) Teste do pedestal; (3) perimetria visual computadorizada branco/branco e azul/amarelo e (4) teste quantitativo de visão de cores Teste de cores de Cambridge. A comparação dos dados de pacientes e controles foi feita com ANOVA e a comparação da capacidade de detecção do dano funcional entre os testes foi feita por meio da análise de curvas ROC. Resultados: ambos os grupos de pacientes manifestaram perdas significantes no mfERG, sensibilidade ao contraste e visão de cores. Em ambos os protocolos de perimetria apenas os pacientes com retinopatia tiveram perdas significativas. As respostas de pacientes com e sem retinopatia não foram significantemente diferentes na maior parte das medidas. Diferenças significativas foram encontradas entre os dois grupos em parte das latências do mfERG e na visão de cores, nos limiares do eixo tritan. (...)

... Na análise entre testes, o mfERG teve os maiores índices de sensibilidade e especificidade, seguido por visão de cores, sensibilidade ao contraste e perimetria, nesta ordem. Na comparação das áreas sob as curvas ROC não houve diferença significativa apenas entre os testes 1, 2 e 4. Conclusões: foram encontradas perdas funcionais estatisticamente significativas na avaliação psicofísica e eletrofisiológica da visão de pacientes diabéticos do tipo 2 sem e com retinopatia diabética. O presente trabalho confirma e amplia o crescente corpo de evidencias de perdas funcionais observadas precocemente no curso da diabetes, na ausência de alterações morfológicas (vasculares) detectáveis na retina. A interpretação dessas perdas precoces é de que tenham origem neural. Nossos achados indicam que a presença de retinopatia leve não teve efeito significativo sobre a maior parte dos aspectos funcionais analisados, corroborando a noção de origem neural das perdas. O efeito da diabetes sobre a função neural não parece ser específico a nenhuma das vias de processamento visual, como indicado pelos testes de sensibilidade ao contraste e de visão de cores. Os achados deste trabalho confirmam a hipótese de que, para o sistema visual, a diabetes seja uma doença neurodegenerativa da retina que pode estabelecer- se mesmo na ausência de retinopatia. Assim, a avaliação dos aspectos funcionais da visão deve ser melhor que a avaliação morfológica da retina para a identificação de pacientes diabéticos sob risco de perda visual

Visual field losses in workers exposed to mercury vapor.

Visual field losses associated with mercury (Hg) exposure have only been assessed in patients exposed to methylmercury. Here we evaluate the automated visual field in 35 ex-workers (30 males; 44.20+/-5.92 years) occupationaly exposed to mercury vapor and 34 controls (21 males; 43.29+/-8.33 years). Visual fields were analyzed with the Humphrey Field Analyzer II (model 750i) using two tests: the standard automated perimetry (SAP, white-on-white) and the short wavelength automated perimetry (SWAP, blue-on-yellow) at 76 locations within a 27 degrees central visual field. Results were analyzed as the mean of the sensitivities measured at the fovea, and at five successive concentric rings, of increasing eccentricity, within the central field. Compared to controls, visual field sensitivities of the experimental group measured using SAP were lower for the fovea as well as for all five eccentricity rings (p<0.05). Sensitivities were significantly lower in the SWAP test (p<0.05) for four of the five extra-foveal eccentricity rings; they were not significant for the fovea (p=0.584) or for the 15 degrees eccentricity ring (p=0.965). These results suggest a widespread reduction of sensitivity in both visual field tests. Previous reports in the literature describe moderate to severe concentric constriction of the visual field in subjects with methylmercury intoxication measured manually with the Goldman perimeter. The present results amplify concerns regarding potential medical risks of exposure to environmental mercury sources by demonstrating significant and widespread reductions of visual sensitivity using the more reliable automated perimetry.

Male prevalence of acquired color vision defects in asymptomatic carriers of Leber's hereditary optic neuropathy.

PURPOSE: Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease resulting in loss of central vision and dyschromatopsia, caused by mitochondrial DNA point mutations. However, only a subset of the mutation carriers becomes affected, with a higher penetrance in males. This study was conducted to investigate chromatic losses in asymptomatic carriers of the LHON mutation. METHODS: Monocular chromatic discrimination was studied with the Cambridge Colour Test (CCT; Cambridge Research Systems, Ltd., Rochester, UK) along the protan, deutan, and tritan cone isolation axes in 46 LHON carriers (15 men) belonging to the same LHON maternal lineage and 74 age-matched control subjects (39 men). Inclusion criteria were absence of ophthalmic complaints and clear ocular media. A detailed neuro-ophthalmic examination was performed in all the LHON carriers. RESULTS: The differences in threshold between carriers and control subjects were significant for the three cone isolation axes at P < 0.0001. Sixty-five percent of the carriers had abnormal protan and/or deutan thresholds; some of those with higher thresholds also had elevated tritan thresholds (13%). The male thresholds were higher and more frequent than those of the women for the protan and deutan axes (ANOVA; P < 0.05), but not for tritan thresholds. In the most severe losses, the women had instances of diffuse defect whereas all the men displayed a red-green defect. CONCLUSIONS: Male LHON asymptomatic carriers had color vision losses with the red-green pattern of dyschromatopsia typical of patients affected with LHON, which includes elevation of tritan thresholds as well. This predominantly parvocellular (red-green) impairment is compatible with the histopathology of LHON, which affects mostly the papillomacular bundle. In contrast with male losses, female losses were less frequent and severe. These gender differences are relevant to understanding LHON pathophysiology, suggesting that hormonal factors may be of great importance.

Chromatic and luminance contrast sensitivities in asymptomatic carriers from a large Brazilian pedigree of 11778 Leber hereditary optic neuropathy.

PURPOSE: To determine whether asymptomatic 11778 LHON carriers demonstrated impairments in (1) chromatic red/green (R/G) and blue/yellow (B/Y) contrast sensitivity functions (CSF) and in (2) luminance contrast sensitivity functions in the spatial CSF (SCSF) and temporal CSF (TCSF) domains. METHODS: Twenty-five carriers (8 male, 17 female; 34.1 +/- 15.1 years of age) of homoplasmic 11778 LHON from the same well-described family and 30 age-matched controls (17 male, 13 female; 29.2 +/- 7.1 years of age) were tested in one eye, randomly selected. Of the 25 eyes tested, 18 had normal fundus, 5 had swelling and microangiopathy, and 2 had temporal pallor. The R/G and B/Y CSFs were obtained after equiluminance correction with bichromatic horizontal sinusoidal gratings at 0.3, 0.7, and 2 cycles per degree (cpd); the SCSFs were obtained with achromatic gratings at 0.3, 2, 6, and 12 cpd; and the TCSFs were obtained at 2, 10, 20, and 33 Hz with sinusoidal modulation of a 2.7 degrees field with a superimposed spatial Gabor function. RESULTS: Differences between carriers and controls were statistically significant for all spatial frequencies of chromatic and luminance SCSFs, but not for the TCSFs. R/G equiluminance settings of carriers differed from those of controls (P < 0.001), requiring higher luminance in the green; B/Y equiluminance settings were not statistically different in carriers and controls. Fundus findings did not correlate with CS results. CONCLUSIONS: Luminance and chromatic spatial CS losses that affected all tested spatial frequencies, are reported in LHON asymptomatic carriers with the mtDNA 11778 mutation. No losses were found in the temporal CSF. An intriguing finding is that the blue system is substantially spared in this LHON family. These represent subclinical visual impairments in otherwise asymptomatic LHON carriers.

Visão de cores e sensibilidade ao contraste em indivíduos com diabete melito: avaliação psicofísica e eletrofisiológica / Color vision and contrast sensitivity in subjects with diabetes mellitus: psychophysical and electrophysiological evaluation

Mesmo antes do estabelecimento de retinopatia detectável no exame clínico, a visão de cores e a sensibilidade ao contraste podem estar afetadas (Dean e cols., 1997; Kurtenbach e cols., 1999). Os déficits sensoriais têm sido atribuídos a alterações vasculares e da função de fotorreceptores (Greenstein e cols., 2000; Lieth e cols., 2000). Contudo, poucas conclusões acerca dos mecanismos fisiopatológicos têm sido obtidas. Este trabalho teve por objetivo identificar - em pacientes diabéticos tipo 2 com fundo de olho normal - possíveis alterações na visão de cores e sensibilidade ao contraste cromático e acromático e correlacionar os prejuízos sensoriais com a função eletrofisiológica da retina. A avaliação sensorial foi feita utilizando o Teste de Cores de Cambridge e o teste de sensibilidade ao contraste Psycho (Ventura e cols., 2003a, Ventura e cols., no prelo) e a função eletrofisiológica foi avaliada usando o eletrorretinograma de campo total (ERG). Os resultados dos pacientes diabéticos (n= 40; idade= 56 anos ± 9 e tempo de diabetes= 7 anos ± 9) foram comparados aos de grupos equiparado por idade. O limiar de discriminação de cores no eixo protan foi superior ao limite normal em 50 per cent dos pacientes, no eixo deutan em 37 per cent e tritan em 28 per cent. A sensibilidade ao contraste cromático nos eixo vermelho/verde e azul/amarelo dos pacientes entre as freqüências espaciais de 0,2 a 2 cpg foi em média 10 dB menor que a dos pacientes, enquanto que na função de sensibilidade ao contraste acromático entre as freqüências espaciais de 0,3 a 20 cpg, a sensibilidade dos pacientes foi apenas 6 dB menor que a dos controles. No ERG, os componentes mais alterados foram os relacionados à atividade da retina interna...(AU)

Color vision loss in patients treated with chloroquine

Patient that make use of chloroquine or hydroxychloroquine, drugs which are frequently administered for treatment of rheumatoid arthritis, lupus erithromatosus or malaria, may suffer alterations in color vision and in contrast sensitivity. The present work evaluates the visual functions of these patients in a joint study of the University of São Paulo (USP), in São Paulo, and of the Federal University of Pará (UFPA), in belém. Thirty two chloroquine user patients without alterations in the eye fundus exam were evaluated in São Paulo (n=10; aged 38 to 71 years; mean=55,8 years) and in Belém (n=22; aged 20 to 67; mean=40 years). The described accumulated chloroquine dose was 45 to 430g (mean=213g; as=152g) for the São Paulo group, and 36 to 540g (mean=174g; sd=183g) for the Belém group. Tests were performed monocularly corrected eye refractive state. Color discrimination was evaluated using the Cambridge Colour Test (CCT): the color discrimination threshold was measured first in the protan, deutan and tritan axes and , in succession, three MacAdamÆs ellipses were determined. The patientÆs color vision was also evaluated with color arrangement tests: the Farnsworth-Munsell 100 Hue (FM100), the Farnsworth-Munsell D15, and the Lanthony Desaturated (D15d) tests. We also measured the contrast sensitivity for black-and-white sine wave grating of twenty two patients. The results were compared with control without ophthalmologic or neuro-ophthalmologic pathologies. Twenty four patients presented acquired dyschromatopsia. There were cases of selective loss (11 patients) and of diffuse loss (13 patients). Although losses were present in the FM100 there was no correlation between the FM100 error score and the ellipse area measured by the CCT. Moreover, three patients that scored normal in the FM100, failed to reach normal threshold in the CCT. The Lanthony test was less sensitive than the other two tests, since it failed to indicate loss in about half the patients, and the D15 was the least sensitive test, having failed to indicate loss in 9 out of 10 patients. Contrast sensitivity was within normal values for patients submitted to this test. The extent of losses in color discrimination was positively correlated with the accumulated dose. The CCT is recommended for follow up since it provides quantitative data that can be directly interpreted in CIE (Commission Internationalle dÆÉclairage) color space.