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Retinal Cases & Brief ReportsTo report novel electroretinographic findings in a genetically confirmed case of achromatopsia.
PURPOSE
To report novel electroretinographic findings in a genetically confirmed case of achromatopsia.
METHODS
A patient with a history of childhood nystagmus, photoaversion, and absent color vision was examined. Electroretinography and fundus examination were performed under anesthesia at the time of corrective surgery for nystagmus. Genomic DNA isolated from peripheral blood was directly sequenced for variations in the CNGA3 and CNGB3 genes.
RESULTS
Ophthalmoscopic examination revealed no distinct abnormalities. Electroretinography obtained under anesthesia at age three years revealed absent photopic responses. The dark-adapted combined responses had reduced b-wave amplitudes resulting in an electronegative configuration. Genetic testing revealed two heterozygous sequence variations present in the coding sequence of the CNGA3 gene (Arg223Trp and Pro372Ser), which have been previously described in the setting of achromatopsia. Sequencing of the patient's parents confirmed that these two variations lie on separate alleles.
CONCLUSION
Novel electroretinography findings in a patient with genetically confirmed achromatopsia are reported. The electronegative configuration in this clinical setting is of unclear etiology; however, it may suggest some component of inner retinal dysfunction.
Topics: Child, Preschool; Color Vision Defects; Electroretinography; Female; Humans; Ophthalmoscopy; Retinal Cone Photoreceptor Cells; Visual Acuity
PubMed: 27820752
DOI: 10.1097/ICB.0000000000000451 -
Journal of AAPOS : the Official... Apr 2020To describe the nystagmus characteristics of subjects with molecularly confirmed CNGB3-associated achromatopsia and report the spectral domain optical coherence...
PURPOSE
To describe the nystagmus characteristics of subjects with molecularly confirmed CNGB3-associated achromatopsia and report the spectral domain optical coherence tomography (SD-OCT) findings in these individuals.
METHODS
Adults and children with CNGB3-achromatopsia underwent visual acuity testing, ocular motility assessments, video nystagmography, and SD-OCT imaging. Qualitative assessment of foveal structure was performed by grading SD-OCT images into one of five categories.
RESULTS
A total of 18 subjects (11 adults) were included. The majority demonstrated a phoria, with manifest strabismus present in only 3 subjects. The predominant nystagmus waveform within the cohort was pure pendular. Nine individuals demonstrated a mixture of waveforms. Nystagmus frequencies were 4-8 cycles/second, with no notable differences in eye movements between adults and children. SD-OCT imaging revealed a continuous ellipsoid zone (EZ) at the fovea in 2 subjects (grade 1) and EZ disruption (grade 2) in the remaining 16. Retinal structure characteristics were symmetrical in both eyes in each subject.
CONCLUSIONS
In our study cohort, nystagmus in CNGB3-associated achromatopsia had distinctive features, and the majority of subjects had retinal abnormalities at the fovea on SD-OCT. Early use of SD-OCT in the clinical work-up may eliminate the need for more invasive investigations, such as neuro-imaging.
Topics: Color Vision Defects; Cyclic Nucleotide-Gated Cation Channels; Fovea Centralis; Humans; Nystagmus, Pathologic; Tomography, Optical Coherence
PubMed: 32151571
DOI: 10.1016/j.jaapos.2019.11.013 -
Archivos de La Sociedad Espanola de... Jan 2019Congenital colour vision deficiencies affect 8% of the male and 0.5% of the female population. The study of colour vision is a complex process due to several factors:... (Review)
Review
INTRODUCTION
Congenital colour vision deficiencies affect 8% of the male and 0.5% of the female population. The study of colour vision is a complex process due to several factors: the psychophysics of vision itself, the difficulty to establish mathematical models for its analysis, the vague correlation of results between different tests, and the influence of external factors such as lighting, the tests condition, or the experience of the examiner and the patient. In the present document, a simplified review was carried out on the main colour vision tests available in clinical practice.
MATERIAL AND METHODS
Once a filtered preliminary review was made of the bibliography related to the study of colour vision using the PubMed search tool, the most used tests in clinical practice were selected according to their frequency of use and the purpose for which they were applied. A bibliographic study was then carried out on each particular test according to the design of the shown stimuli, its target population, and its sensitivity and specificity.
RESULTS
From the 95 publications found using the PubMed search tool, in 41 of them, colour tests were used by researchers in their methodology. From the 64 colour tests used, 19 of them were different (with 4 of them being different tests adapted by research groups, and 2 of them carried out online). The most used tests were the following: Ishihara test (10.88%), Farnsworth-Munsell (7.04%), Farnsworth-Munsell 100 Hue (6.4%), Cambridge Colour Test (3.84%), Hardy-Rand-Rittler (3.2%), tests developed by the groups (2.56%), the Anomaloscope (1.28%), the online tests (1.28%) and, finally, Colour Assessment and Diagnosis (0.64%), Pflüger Trident Colour Plates (0.64%), Toothguide Training Box (0.64%), Lanthony Desaturated D-15 (0.64%), City University Test (0.64%), Universal Colour Discrimination Test (0.64%), and Rabin Cone Contrast Test (0.64%).
CONCLUSIONS
The Anomaloscope is the "gold standard" in terms of colour vision testing, despite its incompatibility with daily clinical practice. It is fairly complex to use, difficult to understand for children, and its practice requires having the time available. Nevertheless, it is possible to reach an accurate approximation through the combination of some of the tests listed in this article. The above mentioned tests are a good alternative to determine the presence of dyschromatopsia in settings closer to daily clinical practice or in less controlled settings than a clinical study. The major drawback among the wide range of tests available for the study of colour vision is the difficulty to compare results between tests, since units of the reported data are usually different, and experience is required for its correct interpretation. Currently, there is no consensus on which colour test is the most complete. It is, therefore, advisable to use at least 2 tests in order to ensure diagnoses, and have more extensive information about the visual perception of patients.
Topics: Color Perception Tests; Color Vision; Color Vision Defects; Humans; Reference Standards; Sensitivity and Specificity
PubMed: 30361001
DOI: 10.1016/j.oftal.2018.08.006 -
Archivos de La Sociedad Espanola de... Jan 2017To evaluate recent evidence concerning the relationship between the exposure to organic solvents and the impairment of colour vision. (Review)
Review
OBJECTIVE
To evaluate recent evidence concerning the relationship between the exposure to organic solvents and the impairment of colour vision.
METHODS
A bibliographic search was conducted for scientific papers published in the last 15 years, in the LILACS, PubMed, Science Direct, EBSCO, and Cochrane databases that included observational studies assessing the relationship between impairment in colour vision and exposure to organic solvents.
RESULTS
Eleven studies were selected that were performed on an economically active population and used the Lanthony D-15 desaturated test (D-15d), measured the exposure to organic solvents, and included unexposed controls. It was found that there is a statistically significant relationship between the exposure to organic solvents and the presence of an impairment in colour vision.
CONCLUSIONS
The results support the hypothesis that exposure to organic solvents could induce acquired dyschromatopsia. The evaluation of colour vision with the D-15d test is simple and sensitive for diagnosis. More studies need to be conducted on this subject in order to better understand the relationship between impaired colour vision and more severe side effects caused by this exposure.
Topics: Air Pollutants, Occupational; Color Perception Tests; Color Vision Defects; Humans; Meta-Analysis as Topic; Observational Studies as Topic; Occupational Diseases; Occupational Exposure; Organic Chemicals; Solvents
PubMed: 27422480
DOI: 10.1016/j.oftal.2016.05.008 -
Investigative Ophthalmology & Visual... Feb 2021Psychophysical and genetic testing provide substantial information about color vision phenotype and genotype. However, neither reveals how color vision phenotypes and...
PURPOSE
Psychophysical and genetic testing provide substantial information about color vision phenotype and genotype. However, neither reveals how color vision phenotypes and genotypes manifest themselves in individual cones, where color vision and its anomalies are thought to originate. Here, we use adaptive-optics phase-sensitive optical coherence tomography (AO-PSOCT) to investigate these relationships.
METHODS
We used AO-PSOCT to measure cone function-optical response to light stimulation-in each of 16 human subjects with different phenotypes and genotypes of color vision (five color-normal, three deuteranopic, two protanopic, and six deuteranomalous trichromatic subjects). We classified three spectral types of cones (S, M, and L), and we measured cone structure-namely cone density, cone mosaic arrangement, and spatial arrangement of cone types.
RESULTS
For the different phenotypes, our cone function results show that (1) color normals possess S, M, and L cones; (2) deuteranopes are missing M cones but are normal otherwise; (3) protanopes are missing L cones but are normal otherwise; and (4) deuteranomalous trichromats are missing M cones but contain evidence of at least two subtypes of L cones. Cone function was consistent with the subjects' genotype in which only the first two M and L genes in the gene array are expressed and was correlated with the estimated spectral separation between photopigments, including in the deuteranomalous trichromats. The L/M cone ratio was highly variable in the color normals. No association was found between cone density and the genotypes and phenotypes investigated, and the cone mosaic arrangement was altered in the dichromats.
CONCLUSIONS
AO-PSOCT is a novel method for assessing color vision phenotype and genotype in single cone cells.
Topics: Adult; Color Perception; Color Vision; Color Vision Defects; Female; Genotype; Humans; Male; Middle Aged; Phenotype; Retinal Cone Photoreceptor Cells; Retinal Pigments; Tomography, Optical Coherence; Young Adult
PubMed: 33544131
DOI: 10.1167/iovs.62.2.8 -
International Ophthalmology Clinics Oct 2021
Topics: Color Vision Defects; Electroretinography; Genetic Therapy; Humans
PubMed: 34584052
DOI: 10.1097/IIO.0000000000000379 -
Human Gene Therapy. Clinical Development Mar 2015Spontaneous canine models exist for several inherited retinal dystrophies. This review will summarize the models and indicate where they have been used in translational... (Review)
Review
Spontaneous canine models exist for several inherited retinal dystrophies. This review will summarize the models and indicate where they have been used in translational gene therapy trials. The RPE65 gene therapy trials to treat childhood blindness are a good example of how studies in dogs have contributed to therapy development. Outcomes in human clinical trials are compared and contrasted with the result of the preclinical dog trials.
Topics: Animals; Blindness; Color Vision Defects; Disease Models, Animal; Dogs; Genetic Therapy; Humans; Leber Congenital Amaurosis; Macular Degeneration; Retinal Dystrophies; cis-trans-Isomerases
PubMed: 25671556
DOI: 10.1089/humc.2014.155 -
Graefe's Archive For Clinical and... Apr 2018The purpose of this study was to characterise alterations in colour discrimination in a cohort of patients with choroideremia prior to gene therapy, using a test...
PURPOSE
The purpose of this study was to characterise alterations in colour discrimination in a cohort of patients with choroideremia prior to gene therapy, using a test previously validated for use in patients with retinal dystrophies.
METHODS
We tested 20 eyes of 10 patients with a diagnosis of choroideremia and an age-matched cohort of 10 eyes of 10 normal controls using the "Cambridge Colour Test" (CCT), in which subjects are required to distinguish the gap in a C presented in one of 4 orientations in a Stilling-type array. Colour discrimination was probed along eight axes in the CIE L*u*v* colour space, and the resulting data were plotted in the CIE 1976 chromaticity diagram and fitted with least-squares ellipses. Subsequently, we estimated the achromatic area for each subject by calculating the area of the resultant discrimination ellipse and calculated sensitivity thresholds along relevant colour confusion axes.
RESULTS
Colour discrimination-as quantified by log of the ellipse area expressed in square 1/1000th units in CIE 1976-was 2.26 (range 1.82 to 2.67) for normal subjects and 3.85 (range 2.35 to 5.41) for choroideremia patients. There was a statistically significant correlation between both achromatic area and red-green colour discrimination at the CCT and BCVA, and to a lesser degree between blue colour discrimination at the CCT and BCVA. The majority of ellipses in choroideremia were aligned close to the tritan axis, and loss of sensitivity was significantly larger in the tritan direction than in the red-green.
CONCLUSIONS
The majority of our patients demonstrated greater loss in tritan discrimination than in red-green colour discrimination using the CCT. There was a significant correlation between achromatic area and BCVA. In keeping with our current understanding of the machinery of colour vision, there was a significant correlation between BCVA and colour discrimination thresholds, which was stronger for red-green colour discrimination, than for tritan colour discrimination. We propose that this and similar tests of colour discrimination may prove to be suitable tools for assessing functional outcomes in gene therapy trials for choroideremia.
Topics: Adult; Aged; Choroid; Choroideremia; Color Perception; Color Perception Tests; Color Vision; Color Vision Defects; Female; Fluorescein Angiography; Fundus Oculi; Humans; Male; Middle Aged; Retinal Pigment Epithelium; Slit Lamp Microscopy; Tomography, Optical Coherence; Visual Acuity; Young Adult
PubMed: 29404760
DOI: 10.1007/s00417-018-3921-0 -
Neurology India 2018
Review
Topics: Aged; Brain Ischemia; Cerebral Cortex; Cerebrovascular Circulation; Color Vision Defects; Databases, Bibliographic; Humans; Magnetic Resonance Imaging; Male; Stroke
PubMed: 29547203
DOI: 10.4103/0028-3886.227322 -
Scientific Reports Jun 2023The ARR3 gene, also known as cone arrestin, belongs to the arrestin family and is expressed in cone cells, inactivating phosphorylated-opsins and preventing cone...
The ARR3 gene, also known as cone arrestin, belongs to the arrestin family and is expressed in cone cells, inactivating phosphorylated-opsins and preventing cone signals. Variants of ARR3 reportedly cause X-linked dominant female-limited early-onset (age < 7 years old) high myopia (< - 6D). Here, we reveal a new mutation (c.228T>A, p.Tyr76*) in ARR3 gene that can cause early-onset high myopia (eoHM) limited to female carriers. Protan/deutan color vision defects were also found in family members, affecting both genders. Using ten years of clinical follow-up data, we identified gradually worsening cone dysfunction/color vision as a key feature among affected individuals. We present a hypothesis that higher visual contrast due to the mosaic of mutated ARR3 expression in cones contributes to the development of myopia in female carriers.
Topics: Child; Female; Humans; Male; Arrestin; Color Vision; Color Vision Defects; Mutation; Myopia; Retinal Cone Photoreceptor Cells
PubMed: 37268727
DOI: 10.1038/s41598-023-36141-0