RESUMEN
Color is an important visual feature that informs behavior, and the retinal basis for color vision has been studied across various vertebrate species. While many studies have investigated how color information is processed in visual brain areas of primate species, we have limited understanding of how it is organized beyond the retina in other species, including most dichromatic mammals. In this study, we systematically characterized how color is represented in the primary visual cortex (V1) of mice. Using large-scale neuronal recordings and a luminance and color noise stimulus, we found that more than a third of neurons in mouse V1 are color-opponent in their receptive field center, while the receptive field surround predominantly captures luminance contrast. Furthermore, we found that color-opponency is especially pronounced in posterior V1 that encodes the sky, matching the statistics of natural scenes experienced by mice. Using unsupervised clustering, we demonstrate that the asymmetry in color representations across cortex can be explained by an uneven distribution of green-On/UV-Off color-opponent response types that are represented in the upper visual field. Finally, a simple model with natural scene-inspired parametric stimuli shows that green-On/UV-Off color-opponent response types may enhance the detection of 'predatory'-like dark UV-objects in noisy daylight scenes. The results from this study highlight the relevance of color processing in the mouse visual system and contribute to our understanding of how color information is organized in the visual hierarchy across species.
Asunto(s)
Visión de Colores , Corteza Visual , Animales , Ratones , Visión de Colores/fisiología , Corteza Visual/fisiología , Percepción de Color/fisiología , Estimulación Luminosa , Ratones Endogámicos C57BL , Neuronas/fisiología , Corteza Visual Primaria/fisiología , MasculinoRESUMEN
Color vision in honeybees is a well-documented perceptual phenomenon including multiple behavioral tests of trichromaticity and color opponency. Data on the combined color/space properties of high order visual neurons in the bee brain is however limited. Here we fill this gap by analyzing the activity of neurons in the anterior optic tract (AOT), a high order brain region suggested to be involved in chromatic processing. The spectral response properties of 72 units were measured using UV, blue and green light stimuli presented in 266 positions of the visual field. The majority of these units comprise combined chromatic-spatial processing properties. We found eight different neuron categories in terms of their spectral, spatial and temporal response properties. Color-opponent neurons, the most abundant neural category in the AOT, present large receptive fields and activity patterns that were typically opponent between UV and blue or green, particularly during the on-tonic response phase. Receptive field shapes and activity patterns of these color processing neurons are more similar between blue and green, than between UV and blue or green. We also identified intricate spatial antagonism and double spectral opponency in some receptive fields of color-opponent units. Stimulation protocols with different color combinations applied to 21 AOT units allowed us to uncover additional levels of spectral antagonism and hidden inhibitory inputs, even in some units that were initially classified as broad-band neurons based in their responses to single spectral lights. The results are discussed in the context of floral color discrimination and celestial spectral gradients.
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Encéfalo , Percepción de Color , Neuronas , Animales , Abejas/fisiología , Neuronas/fisiología , Percepción de Color/fisiología , Encéfalo/fisiología , Estimulación Luminosa , Vías Visuales/fisiología , Campos Visuales/fisiología , Visión de Colores/fisiologíaRESUMEN
The neural pathways that start human color vision begin in the complex synaptic network of the foveal retina where signals originating in long (L), middle (M), and short (S) wavelength-sensitive cone photoreceptor types are compared through antagonistic interactions, referred to as opponency. In nonhuman primates, two cone opponent pathways are well established: an L vs. M cone circuit linked to the midget ganglion cell type, often called the red-green pathway, and an S vs. L + M cone circuit linked to the small bistratified ganglion cell type, often called the blue-yellow pathway. These pathways have been taken to correspond in human vision to cardinal directions in a trichromatic color space, providing the parallel inputs to higher-level color processing. Yet linking cone opponency in the nonhuman primate retina to color mechanisms in human vision has proven particularly difficult. Here, we apply connectomic reconstruction to the human foveal retina to trace parallel excitatory synaptic outputs from the S-ON (or "blue-cone") bipolar cell to the small bistratified cell and two additional ganglion cell types: a large bistratified ganglion cell and a subpopulation of ON-midget ganglion cells, whose synaptic connections suggest a significant and unique role in color vision. These two ganglion cell types are postsynaptic to both S-ON and L vs. M opponent midget bipolar cells and thus define excitatory pathways in the foveal retina that merge the cardinal red-green and blue-yellow circuits, with the potential for trichromatic cone opponency at the first stage of human vision.
Asunto(s)
Percepción de Color , Visión de Colores , Fóvea Central , Células Fotorreceptoras Retinianas Conos , Células Ganglionares de la Retina , Humanos , Fóvea Central/fisiología , Células Fotorreceptoras Retinianas Conos/fisiología , Células Fotorreceptoras Retinianas Conos/metabolismo , Visión de Colores/fisiología , Células Ganglionares de la Retina/fisiología , Percepción de Color/fisiología , Células Bipolares de la Retina/fisiología , Células Bipolares de la Retina/metabolismo , Retina/fisiología , Masculino , Femenino , Adulto , Conectoma , Vías Visuales/fisiologíaRESUMEN
PURPOSE: To evaluate whether colour vision normal (CVN) adults pass two Fletcher-Evans (CAM) lantern tests and to investigate the impact of imposed blur on Ishihara, CAM lantern and computerised colour discrimination test (colour assessment and diagnosis test [CAD] and Cambridge colour test [CCT]) results. METHODS: In a pilot experiment, 20 (16 CVN and 4 colour vision deficient [CVD]) participants with normal VA were tested with the CAM lantern. In the main experiment, the impact of imposed dioptric blur (up to +8.00 D) on visual acuity and the Ishihara test, CAM lantern, CAD and CCT was assessed for 15 CVN participants. RESULTS: CVN participants can fail the CAM lantern, with specificity of 81.25% (aviation mode) and 75% (clinical mode), despite following the test requirements of participants having at least 0.18 logMAR (6/9) in the better eye. With blur, test accuracy was affected. As expected, significant detrimental effects of blur on test results were found for logMAR VA and CAM lantern (aviation) with +1.00 D or higher. Ishihara, CAD and CCT results were not detrimentally affected until +8.00 D. Yellow-blue discrimination was more affected by blur for the CAD than the CCT, which was not explained by the different colour spaces used or vectors tested. CONCLUSION: False-positive findings on lantern colour vision tests with small apertures are likely to be increased in patients with blur due to uncorrected refractive error or ocular and visual pathway disease. Other colour vision tests with larger stimuli are more robust to blur.
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Pruebas de Percepción de Colores , Defectos de la Visión Cromática , Visión de Colores , Agudeza Visual , Humanos , Pruebas de Percepción de Colores/métodos , Adulto , Masculino , Femenino , Agudeza Visual/fisiología , Defectos de la Visión Cromática/diagnóstico , Defectos de la Visión Cromática/fisiopatología , Visión de Colores/fisiología , Adulto Joven , Proyectos Piloto , Percepción de Color/fisiología , Persona de Mediana Edad , Reproducibilidad de los ResultadosRESUMEN
Photopic negative response (PhNR), an index of retinal ganglion cell (RGC) function, is impaired in patients with optic pathway gliomas (OPGs). The aim of this longitudinal study was to evaluate whether PhNR deteriorates over time in OPG patients. Fourteen pediatric patients affected by OPG (4 males and 10 females, mean age 12.4 ± 5.7 years, 8 with neurofibromatosis type 1 [NF1]) with ≥12 months of follow-up and ≥2 evaluations, were included in this retrospective study. All patients had received chemotherapy, with or without OPG surgical resection, at least 5 years prior to the study. At baseline, all patients underwent a complete ophthalmological examination. Follow-up included clinical examination and PhNR measurement as well as brain MRI (according to pediatric oncologist indications) every 6 or 12 months. Mean follow-up duration was 16.7 ± 7.5 months (range 12-36 months). Photopic electroretinograms were elicited by 2.0 cd-s/m2 Ganzfeld white flashes presented on a steady 20 cd/m2 white background. The PhNR amplitude was measured as the difference between baseline and the maximal negative amplitude (minimum) of the negative wave, following the photopic b-wave. Compared to baseline, mean PhNR amplitude was significantly decreased at the end of follow-up (p = 0.008). NF1-related OPGs exhibited a decline in PhNR amplitude (p = 0.005) and an increase in PhNR peak-time during the follow-up (p = 0.013), whereas sporadic OPGs showed no significant changes. Tumor size remained stable in all patients on MRI. PhNR amplitude decreased over the observation period, suggesting progressive RGC dysfunction in NF1-related pediatric OPGs, despite stable size on MRI imaging. PhNR could serve as a non-invasive objective tool for assessing longitudinal changes in RGC function in the clinical management of childhood OPG.
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Visión de Colores , Electrorretinografía , Glioma del Nervio Óptico , Células Ganglionares de la Retina , Humanos , Femenino , Masculino , Células Ganglionares de la Retina/patología , Niño , Estudios Retrospectivos , Glioma del Nervio Óptico/fisiopatología , Adolescente , Visión de Colores/fisiología , Estudios de Seguimiento , Imagen por Resonancia Magnética , Estimulación Luminosa , Preescolar , Agudeza Visual/fisiologíaRESUMEN
Visual function comprises three principles: light sensation, color sensation, and minimum separable sensation. Although clinical evaluation of light sensation and visual acuity have been remarkably developed through comprehensive application of various methods, the test methods to evaluate color sensation in the clinical field have not reflected these various significant developments after their recommendation at the International Congress of Ophthalmology in 1933. To date, various research methods in color vision have been invented on the basis of clinical evaluation methods, most of which were limited to laboratory investigations and were not applied to the clinical field. In this review, the author focuses on both the currently clinical available evaluation methods and the clinically applicable methods based on the present laboratory research studies.
Asunto(s)
Pruebas de Percepción de Colores , Percepción de Color , Visión de Colores , Humanos , Visión de Colores/fisiología , Pruebas de Percepción de Colores/métodos , Percepción de Color/fisiología , Agudeza Visual/fisiología , Defectos de la Visión Cromática/diagnóstico , Defectos de la Visión Cromática/fisiopatologíaRESUMEN
SIGNIFICANCE: Imposing a time limit on the Farnsworth D15 test may prevent patients from compromising the test. PURPOSE: This study aimed to investigate the effect of test time on the Farnsworth D15 color vision test in unpracticed and practiced subjects and determine an optimal test time. METHODS: Twenty-one subjects (mean/standard deviation age, 33.1/9.3 years) with a range of congenital color vision deficiency participated in the study. Pseudoisochromatic plate screening, Farnsworth D15, and anomaloscope testing were performed for classification purposes. At each of 2 visits, 10 trials of the Farnsworth D15 were performed with a range in test times from 30 seconds to 10 minutes. Between visits, subjects practiced the test. Major crossovers were used as the outcome measure. A repeated-measures analysis of variance compared the scores across trials. Post hoc Dunnett's testing analyzed the pairwise data. RESULTS: Although no significant difference in the mean number of major crossovers was found across the 10 trials for the first visit ( F (9, 180) = 1.30, p=0.24), a significant difference was found for the second visit ( F (9, 180) = 4.77, p<0.001). The range of mean number of major crossovers for the second visit was 1.71 to 5.1, with the 30-second trial resulting in the largest number of major crossovers and the longest trial resulting in the smallest number of major crossovers. Analysis showed that a 2-minute time limit resulted in a Farnsworth D15 outcome that would be expected based on the anomaloscope for a majority of subjects. CONCLUSIONS: In this study, test time was found to affect performance in practiced subjects but not in unpracticed subjects. Based on this study, we recommend enforcing a time limit of 2 minutes to discourage those who try to pass the Farnsworth D15 through practice. Additional measures, such as recording patient behavior, can also be taken.
Asunto(s)
Pruebas de Percepción de Colores , Defectos de la Visión Cromática , Humanos , Defectos de la Visión Cromática/fisiopatología , Defectos de la Visión Cromática/diagnóstico , Adulto , Masculino , Femenino , Factores de Tiempo , Pruebas de Percepción de Colores/métodos , Adulto Joven , Persona de Mediana Edad , Reproducibilidad de los Resultados , Percepción de Color/fisiología , Estudios de Seguimiento , Visión de Colores/fisiologíaRESUMEN
OBJECTIVES: To examine relationships between visual function (ie, contrast sensitivity, visual field, color vision, and motion perception) and cognitive impairment, including any definition of "cognitive impairment," mild cognitive impairment, or dementia. DESIGN: Systematic review and meta-analyses. SETTING AND PARTICIPANTS: Any settings; participants with (cases) or without (controls) cognitive impairment. METHODS: We searched 4 databases (to January 2024) and included published studies that compared visual function between cases and controls. Standardized mean differences (SMD) with 95% CIs were calculated where data were available. Data were sufficient for meta-analyses when cases were people with dementia. The Joanna Briggs Institute checklists were used for quality assessment. RESULTS: Fifty-one studies/69 reports were included. Cross-sectional evidence shows that people with dementia had worse contrast sensitivity function and color vision than controls: measured by contrast sensitivity (log units) on letter charts, SMD -1.22 (95% CI -1.98, -0.47), or at varied spatial frequencies, -0.92 (-1.28, -0.57); and by pseudoisochromatic plates, -1.04 (-1.59, -0.49); color arrangement, -1.30 (-2.31, -0.29); or matching tests, -0.51 (-0.78, -0.24). They also performed more poorly on tests of motion perception, -1.20 (-1.73, -0.67), and visual field: mean deviation, -0.87 (-1.29, -0.46), and pattern standard deviation, -0.69 (-1.24, -0.15). Results were similar when cases were limited to participants with clinically diagnosed Alzheimer disease. Sources of bias included lack of clarity on study populations or settings and definitions of cognitive impairment. The 2 included longitudinal studies with follow-ups of approximately 10 years were of good quality but reported inconsistent results. CONCLUSIONS AND IMPLICATIONS: In the lack of longitudinal data, cross-sectional studies indicate that individuals with cognitive impairment have poorer visual function than those with normal cognition. Additional longitudinal data are needed to understand whether poor visual function precedes cognitive impairment and the most relevant aspects of visual function, dementia pathologies, and domains of cognition.
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Disfunción Cognitiva , Sensibilidad de Contraste , Percepción de Movimiento , Humanos , Sensibilidad de Contraste/fisiología , Percepción de Movimiento/fisiología , Disfunción Cognitiva/fisiopatología , Campos Visuales/fisiología , Visión de Colores/fisiología , Anciano , Femenino , Masculino , Demencia/fisiopatología , Percepción de Color/fisiología , Estudios TransversalesRESUMEN
PURPOSE: To evaluate mesopic and photopic contrast sensitivity in patients with congenital red-green color vision deficiency regarding with and without glare conditions and to compare these findings with age- and gender-matched healthy controls with normal color vision. METHODS: Patients with congenital red-green color vision deficiency and age- and gender-matched healthy controls were included in this cross-sectional comparative study. Contrast sensitivity measurements were taken from all subjects in 4 different conditions; binocular mesopic-without glare, mesopic-with glare, photopic-without glare, photopic-with glare, and the results were compared. RESULTS: Twenty one patients with color vision deficiency (13 deuteranopic, 8 protanopic) and 22 age- and gender-matched healthy controls were included in the study. The mean age was 35.2 ± 13.5 years in the protan group, 30.6 ± 7.7 years in the deutan group, 32.0 ± 8.8 years in the control group, and there was no significant difference in age between the groups (P > 0.05). The mean mesopic and photopic contrast sensitivity values of the groups at all spatial frequencies (1.5, 3, 6, 12, 18 cpd) were not statistically significant when evaluated by the multifactor repeated measures test of ANOVA to evaluate the effect of light conditions (with and without glare) (P > .05). CONCLUSION: Mesopic and photopic contrast sensitivity values of patients with congenital red-green color vision deficiency were similar to healthy controls regarding with and without glare conditions.
Asunto(s)
Defectos de la Visión Cromática , Visión de Colores , Sensibilidad de Contraste , Humanos , Sensibilidad de Contraste/fisiología , Defectos de la Visión Cromática/fisiopatología , Defectos de la Visión Cromática/diagnóstico , Femenino , Masculino , Estudios Transversales , Adulto , Visión de Colores/fisiología , Adulto Joven , Persona de Mediana Edad , Visión Mesópica/fisiología , Deslumbramiento , Agudeza Visual , AdolescenteRESUMEN
In the perception of color, wavelengths of light reflected off objects are transformed into the derived quantities of brightness, saturation and hue. Neurons responding selectively to hue have been reported in primate cortex, but it is unknown how their narrow tuning in color space is produced by upstream circuit mechanisms. We report the discovery of neurons in the Drosophila optic lobe with hue-selective properties, which enables circuit-level analysis of color processing. From our analysis of an electron microscopy volume of a whole Drosophila brain, we construct a connectomics-constrained circuit model that accounts for this hue selectivity. Our model predicts that recurrent connections in the circuit are critical for generating hue selectivity. Experiments using genetic manipulations to perturb recurrence in adult flies confirm this prediction. Our findings reveal a circuit basis for hue selectivity in color vision.
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Drosophila , Animales , Percepción de Color/fisiología , Vías Visuales/fisiología , Neuronas/fisiología , Lóbulo Óptico de Animales no Mamíferos/fisiología , Estimulación Luminosa/métodos , Visión de Colores/fisiología , Conectoma , Red Nerviosa/fisiologíaRESUMEN
Objective assessment of the visual system can be performed electrophysiologically using the visual evoked potential (VEP). In many clinical circumstances, this is performed using high contrast achromatic patterns or diffuse flash stimuli. These methods are clinically valuable but they may only assess a subset of possible physiological circuitries within the visual system, particularly those involved in achromatic (luminance) processing. The use of chromatic VEPs (cVEPs) in addition to standard VEPs can inform us of the function or dysfunction of chromatic pathways. The chromatic VEP has been well studied in human health and disease. Yet, to date our knowledge of their underlying mechanisms and applications remains limited. This likely reflects a heterogeneity in the methodology, analysis and conclusions of different works, which leads to ambiguity in their clinical use. This review sought to identify the primary methodologies employed for recording cVEPs. Furthermore cVEP maturation and application in understanding the function of the chromatic system under healthy and diseased conditions are reviewed. We first briefly describe the physiology of normal colour vision, before describing the methodologies and historical developments which have led to our understanding of cVEPs. We thereafter describe the expected maturation of the cVEP, followed by reviewing their application in several disorders: congenital colour vision deficiencies, retinal disease, glaucoma, optic nerve and neurological disorders, diabetes, amblyopia and dyslexia. We finalise the review with recommendations for testing and future directions.
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Potenciales Evocados Visuales , Humanos , Potenciales Evocados Visuales/fisiología , Defectos de la Visión Cromática/fisiopatología , Visión de Colores/fisiología , Percepción de Color/fisiologíaRESUMEN
Late development of color vision improves object recognition.
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Desarrollo Infantil , Percepción de Color , Visión de Colores , Reconocimiento Visual de Modelos , Humanos , Percepción de Color/fisiología , Visión de Colores/fisiología , LactanteRESUMEN
Primary congenital glaucoma is a rare disease that occurs in early birth and can lead to low vision. Evaluating affected children is challenging and there is a lack of studies regarding color vision in pediatric glaucoma patients. This cross-sectional study included 21 eyes of 13 children with primary congenital glaucoma who were assessed using the Farnsworth D-15 test to evaluate color vision discrimination and by spectral domain optical coherence tomography to measure retinal fiber layer thickness. Age, visual acuity, cup-to-disc ratio and spherical equivalent data were also collected. Global and sectional circumpapillary and macular retinal fiber layer thicknesses were measured and compared based on color vision test performance. Four eyes (19%) failed the color vision test with diffuse dyschromatopsia patterns. Only age showed statistical significance in color vision test performance. Global and sectional circumpapillary and macular retinal fiber layer thicknesses were similar between the color test outcomes dyschromatopsia and normal. While the color vision test could play a role in assessing children with primary congenital glaucoma, further studies are needed to correlate it with damage to retinal fiber layer thickness.
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Visión de Colores , Glaucoma , Tomografía de Coherencia Óptica , Humanos , Femenino , Masculino , Niño , Estudios Transversales , Tomografía de Coherencia Óptica/métodos , Glaucoma/congénito , Glaucoma/diagnóstico por imagen , Glaucoma/fisiopatología , Glaucoma/patología , Glaucoma/diagnóstico , Preescolar , Visión de Colores/fisiología , Agudeza Visual , Adolescente , Defectos de la Visión Cromática/fisiopatología , Defectos de la Visión Cromática/congénito , Percepción de Color/fisiología , Retina/diagnóstico por imagen , Retina/patología , Retina/fisiopatología , Pruebas de Percepción de ColoresRESUMEN
This review discusses the current state of knowledge regarding the phenomenon called two-photon vision. It involves the visual perception of pulsed infrared beams in the range of 850-1200 nm as having colors corresponding to one-half of the IR wavelengths. It is caused by two-photon absorption (TPA), which occurs when the visual photopigment interacts simultaneously with two infrared photons. The physical mechanism of TPA is described, and implications about the efficiency of the process are considered. The spectral range of two-photon vision is defined, along with a detailed discussion of the known differences in color perception between normal and two-photon vision. The quadratic dependence of the luminance of two-photon stimuli on the power of the stimulating beam is also explained. Examples of recording two-photon vision in the retinas of mice and monkeys are provided from the literature. Finally, applications of two-photon vision are discussed, particularly two-photon microperimetry, which has been under development for several years; and the potential advantages of two-photon retinal displays are explained.
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Percepción de Color , Rayos Infrarrojos , Fotones , Animales , Humanos , Percepción de Color/fisiología , Visión de Colores/fisiología , Ratones , Estimulación Luminosa/métodosRESUMEN
Perceptual learning is the improvement of perceptual performance after repeated practice on a perceptual task. Studies on perceptual learning in color vision are limited. In this study, we measured the impact of color discrimination repetitions at a specific base color on color perception for entire hues. Participants performed five sessions of color discrimination training (200 or 300 trials per session) over five days, at colors on either the negative or positive direction of the L-M color axis, based on group assignment. We administered three color perception assessments (unique hues, color category boundaries, and color appearance) before and after the sessions to evaluate perceptual changes after training. The results showed declines in color discrimination thresholds after training, as expected. Additionally, the training influenced outcomes across all three assessment types. After the training, the perceived color appearance changed near the trained color along the stimulus hue, and some of the unique hues and the color category boundaries moved significantly toward the trained color. These findings indicate that short-term repetitions of color discrimination training can alter color representations in the visual system, distorting color perception around the trained color.
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Percepción de Color , Humanos , Percepción de Color/fisiología , Femenino , Masculino , Adulto Joven , Adulto , Estimulación Luminosa , Color , Aprendizaje/fisiología , Visión de Colores/fisiología , Aprendizaje Discriminativo/fisiología , Discriminación en PsicologíaRESUMEN
With the advances in smartphone and tablet screens, as well as their processing power and software, mobile apps have been developed reporting to assess visual function. This review assessed those mobile apps that have been evaluated in the scientific literature to measure visual acuity, reading metrics, contrast sensitivity, stereoacuity, colour vision and visual fields; these constitute just a small percentage of the total number of mobile apps reporting to measure these metrics available for tablets and smartphones. In general, research suggests that most of the mobile apps evaluated can accurately mimic most traditionally paper-based tests of visual function, benefitting from more even illumination from the backlit screen and aspects such as multiple tests and versions (to minimise memorisation) being available on the same equipment. Some also utilise the in-built device sensors to monitor aspects such as working distance and screen tilt. As the consequences of incorrectly recording visual function and using this to inform clinical management are serious, clinicians must check on the validity of a mobile app before adopting it as part of clinical practice.
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Aplicaciones Móviles , Pruebas de Visión , Agudeza Visual , Humanos , Agudeza Visual/fisiología , Pruebas de Visión/métodos , Pruebas de Visión/instrumentación , Sensibilidad de Contraste/fisiología , Campos Visuales/fisiología , Trastornos de la Visión/diagnóstico , Trastornos de la Visión/fisiopatología , Visión de Colores/fisiología , Teléfono Inteligente , LecturaRESUMEN
PURPOSE: To describe the phenotype of Danish patients with genetically verified achromatopsia (ACHM) with special focus on signs of progression on structural or functional parameters, and possible genotype-phenotype correlations. METHODS: Forty-eight patients were identified, with disease-causing variants in five different genes: CNGA3, CNGB3, GNAT2, PDE6C and PDE6H. Longitudinal evaluation was possible for 11 patients and 27 patients participated in a renewed in-depth phenotyping consisting of visual acuity assessment, optical coherence tomography (OCT), fundus autofluorescence, colour vision evaluation, contrast sensitivity, mesopic microperimetry and full-field electroretinography. Foveal morphology was evaluated based on OCT images for all 48 patients using a grading system based on the integrity of the hyperreflective photoreceptor band, the inner segment ellipsoid zone (ISe). Signs of progression were evaluated based on longitudinal data and correlation with age. RESULTS: We found a statistically significant positive correlation between OCT grade and age (Spearman ρ = 0.62, p < 0.0001) and we observed changes in the foveal morphology in 2 of 11 patients with ≥5 years of follow-up. We did not find any convincing correlation between age and functional parameters (visual acuity, retinal sensitivity and contrast sensitivity) nor did we find correlation between structural and functional parameters, or any clear genotype-phenotype correlation. CONCLUSIONS: Some patients with ACHM demonstrate signs of progressive foveal changes in OCT characteristics with increasing age. This is relevant in terms of possible new treatments. However, functional characteristics, such as visual acuity, remained stable despite changing foveal structure. Thus, seen from a patient perspective, ACHM can still be considered a non-progressive condition.
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Defectos de la Visión Cromática , Canales Catiónicos Regulados por Nucleótidos Cíclicos , Electrorretinografía , Fenotipo , Tomografía de Coherencia Óptica , Agudeza Visual , Humanos , Defectos de la Visión Cromática/genética , Defectos de la Visión Cromática/fisiopatología , Defectos de la Visión Cromática/diagnóstico , Masculino , Tomografía de Coherencia Óptica/métodos , Femenino , Agudeza Visual/fisiología , Adulto , Dinamarca , Adolescente , Adulto Joven , Niño , Persona de Mediana Edad , Canales Catiónicos Regulados por Nucleótidos Cíclicos/genética , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 6/genética , Mutación , Pruebas del Campo Visual , Sensibilidad de Contraste/fisiología , Estudios de Seguimiento , Angiografía con Fluoresceína/métodos , Proteínas del Ojo/genética , Guanilato Ciclasa/genética , Campos Visuales/fisiología , Estudios de Asociación Genética , Análisis Mutacional de ADN , ADN/genética , Visión de Colores/fisiologíaRESUMEN
Interphotoreceptor retinoid-binding protein (IRBP) is an abundant glycoprotein in the subretinal space bound by the photoreceptor (PR) outer segments and the processes of the retinal pigmented epithelium (RPE). IRBP binds retinoids, including 11-cis-retinal and all-trans-retinol. In this study, visual function for demanding visual tasks was assessed in IRBP knock-out (KO) mice. Surprisingly, IRBP KO mice showed no differences in scotopic critical flicker frequency (CFF) compared to wildtype (WT). However, they did have lower photopic CFF than WT. IRBP KO mice had reduced scotopic and photopic acuity and contrast sensitivity compared to WT. IRBP KO mice had a significant reduction in outer nuclear layer (ONL) thickness, PR outer and inner segment, and full retinal thickness (FRT) compared to WT. There were fewer cones in IRBP KO mice. Overall, these results confirm substantial loss of rods and significant loss of cones within 30 days. Absence of IRBP resulted in cone circuit damage, reducing photopic flicker, contrast sensitivity, and spatial frequency sensitivity. The c-wave was reduced and accelerated in response to bright steps of light. This result also suggests altered retinal pigment epithelium activity. There appears to be a compensatory mechanism such as higher synaptic gain between PRs and bipolar cells since the loss of the b-wave did not linearly follow the loss of rods, or the a-wave. Scotopic CFF is normal despite thinning of ONL and reduced scotopic electroretinogram (ERG) in IRBP KO mice, suggesting either a redundancy or plasticity in circuits detecting (encoding) scotopic flicker at threshold even with substantial rod loss.
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Proteínas del Ojo , Visión Nocturna , Retina , Proteínas de Unión al Retinol , Retina/fisiología , Retina/ultraestructura , Estimulación Luminosa , Proteínas del Ojo/genética , Proteínas del Ojo/fisiología , Proteínas de Unión al Retinol/genética , Proteínas de Unión al Retinol/fisiología , Ratones Noqueados , Animales , Ratones , Fusión de Flicker/genética , Fusión de Flicker/fisiología , Visión de Colores/genética , Visión de Colores/fisiología , Agudeza Visual/genética , Agudeza Visual/fisiología , Visión Nocturna/genética , Visión Nocturna/fisiología , Tomografía de Coherencia Óptica , Masculino , FemeninoRESUMEN
Purpose: To explore the relationship of color vision deficiency with myopia progression and axial elongation in Chinese primary school children during a five-year cohort study. Methods: A total of 2849 grade 1 students (aged 7.1 ± 0.4 years) from 11 primary schools were enrolled and followed up for five years. Cycloplegic autorefraction and axial length were measured annually. Color vision testing was performed using Ishihara's test and the City University color vision test. Results: The prevalence of color vision deficiency was 1.68%, with 2.81% in boys and 0.16% in girls. Color-deficient cases consisted of 91.6% deutan and 8.3% protan. Over the five years, the cumulative incidence of myopia was 35.4% (17/48) in the color-vision deficiency group, which was lower than the 56.7% (1017/1794) in the color normal group (P = 0.004). Over the five-year study period, the change in spherical equivalent refraction in the color vision-deficiency group (-1.81 D) was also significantly lower than that in the color normal group (-2.41 D) (P = 0.002). Conclusions: The lower incidence and slower progression of myopia in children with color-vision deficiency over the five-year follow-up period suggest that color-deficient individuals are less susceptible to myopia onset and development.
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Defectos de la Visión Cromática/etiología , Visión de Colores/fisiología , Miopía/complicaciones , Refracción Ocular/fisiología , Longitud Axial del Ojo , Niño , Preescolar , China/epidemiología , Defectos de la Visión Cromática/epidemiología , Defectos de la Visión Cromática/fisiopatología , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Morbilidad/tendencias , Miopía/epidemiología , Miopía/fisiopatología , Estudios Retrospectivos , Factores de TiempoRESUMEN
Deficits in color vision and related retinal changes hold promise as early screening biomarkers in patients with Alzheimer's disease. This study aimed to determine a cut-off score that can screen for Alzheimer's dementia using a novel color vision threshold test named the red, green, and blue (RGB) modified color vision plate test (RGB-vision plate). We developed the RGB-vision plate consisting of 30 plates in which the red and green hues of Ishihara Plate No.22 were sequentially adjusted. A total of 108 older people participated in the mini-mental state examination (MMSE), Ishihara plate, and RGB-vision plate. For the analyses, the participants were divided into two groups: Alzheimer's dementia (n = 42) and healthy controls (n = 38). K-means cluster analysis and ROC curve analysis were performed to identify the most appropriate cut-off score. As a result, the cut-off screening score for Alzheimer's dementia on the RGB-vision plate was set at 25, with an area under the curve of 0.773 (p<0.001). Moreover, there was a negative correlation between the RGB-vision plate thresholds and MMSE scores (r = -0.36, p = 0.02). In conclusion, patients with Alzheimer's dementia had a deficit in color vision. The RGB-vision plate is a potential early biomarker that may adequately detect Alzheimer's dementia.