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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 -
Genes Jun 2023Achromatopsia (ACHM) is a congenital cone photoreceptor disorder characterized by reduced visual acuity, nystagmus, photophobia, and very poor or absent color vision....
Achromatopsia (ACHM) is a congenital cone photoreceptor disorder characterized by reduced visual acuity, nystagmus, photophobia, and very poor or absent color vision. Pathogenic variants in six genes encoding proteins composing the cone phototransduction cascade (, , , , ) and of the unfolded protein response () have been related to ACHM cases, while and alone are responsible for most cases. Herein, we provide a clinical and molecular overview of 42 Brazilian patients from 38 families affected with ACHM related to biallelic pathogenic variants in the and genes. Patients' genotype and phenotype were retrospectively evaluated. The majority of variants were missense, and the most prevalent variant was c.1148delC (p.Thr383Ilefs*13), resulting in a frameshift and premature stop codon, which is compatible with previous publications in the literature. A novel variant c.1893T>A (p.Tyr631*) in the gene is reported for the first time in this study. A great variability in morphologic findings was observed in our patients, although no consistent correlation with age and disease stage in OCT foveal morphology was found. The better understanding of the genetic variants landscape in the Brazilian population will help in the diagnosis of this disease.
Topics: Humans; Color Vision Defects; Mutation; Brazil; Retrospective Studies; Cyclic Nucleotide-Gated Cation Channels
PubMed: 37372476
DOI: 10.3390/genes14061296 -
Quality of Life Research : An... Apr 2019This article shows an integrative review on the impact that abnormal color vision may have on the daily routine of individuals. (Review)
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.
Topics: Color Vision; Color Vision Defects; Female; Humans; Male; Quality of Life
PubMed: 30443703
DOI: 10.1007/s11136-018-2030-1 -
Brain : a Journal of Neurology Nov 2022Recent advances in regenerative therapy have placed the treatment of previously incurable eye diseases within arms' reach. Achromatopsia is a severe monogenic heritable...
Recent advances in regenerative therapy have placed the treatment of previously incurable eye diseases within arms' reach. Achromatopsia is a severe monogenic heritable retinal disease that disrupts cone function from birth, leaving patients with complete colour blindness, low acuity, photosensitivity and nystagmus. While successful gene-replacement therapy in non-primate models of achromatopsia has raised widespread hopes for clinical treatment, it was yet to be determined if and how these therapies can induce new cone function in the human brain. Using a novel multimodal approach, we demonstrate for the first time that gene therapy can successfully activate dormant cone-mediated pathways in children with achromatopsia (CNGA3- and CNGB3-associated, 10-15 years). To test this, we combined functional MRI population receptive field mapping and psychophysics with stimuli that selectively measure cone photoreceptor signalling. We measured cortical and visual cone function before and after gene therapy in four paediatric patients, evaluating treatment-related change against benchmark data from untreated patients (n = 9) and normal-sighted participants (n = 28). After treatment, two of the four children displayed strong evidence for novel cone-mediated signals in visual cortex, with a retinotopic pattern that was not present in untreated achromatopsia and which is highly unlikely to emerge by chance. Importantly, this change was paired with a significant improvement in psychophysical measures of cone-mediated visual function. These improvements were specific to the treated eye, and provide strong evidence for successful read-out and use of new cone-mediated information. These data show for the first time that gene replacement therapy in achromatopsia within the plastic period of development can awaken dormant cone-signalling pathways after years of deprivation. This reveals unprecedented neural plasticity in the developing human nervous system and offers great promise for emerging regenerative therapies.
Topics: Humans; Child; Color Vision Defects; Cyclic Nucleotide-Gated Cation Channels; Electroretinography; Retinal Cone Photoreceptor Cells; Genetic Therapy
PubMed: 35998912
DOI: 10.1093/brain/awac226 -
Advanced Healthcare Materials Jun 2018Color vision deficiency (color blindness) is an inherited genetic ocular disorder. While no cure for this disorder currently exists, several methods can be used to...
Color vision deficiency (color blindness) is an inherited genetic ocular disorder. While no cure for this disorder currently exists, several methods can be used to increase the color perception of those affected. One such method is the use of color filtering glasses which are based on Bragg filters. While these glasses are effective, they are high cost, bulky, and incompatible with other vision correction eyeglasses. In this work, a rhodamine derivative is incorporated in commercial contact lenses to filter out the specific wavelength bands (≈545-575 nm) to correct color vision blindness. The biocompatibility assessment of the dyed contact lenses in human corneal fibroblasts and human corneal epithelial cells shows no toxicity and cell viability remains at 99% after 72 h. This study demonstrates the potential of the dyed contact lenses in wavelength filtering and color vision deficiency management.
Topics: Color Vision Defects; Contact Lenses, Hydrophilic; Cornea; Epithelial Cells; Female; Humans; Male; Materials Testing; Rhodamines
PubMed: 29696828
DOI: 10.1002/adhm.201800152 -
Clinics in Dermatology 2019The physical nature of color is well known and is based on its wavelength; however, the color perception in humans and animals is much less understood and is based...
The physical nature of color is well known and is based on its wavelength; however, the color perception in humans and animals is much less understood and is based mostly only on some assumptions and theories. We present the current knowledge on both of these topics, describe the anatomic basis for color vision, and discuss color vision deficiencies. Color vision disturbances can not only interfere with everyday activities but also impede performing specific professions. Commercial or military pilots, electricians, defense forces including paramilitary, food and art critics, and some physicians, scientists, and engineers may not be able to perform their professions to the full extent. Colors play an important role in the culture of various societies. The same color can have the opposite meaning in different cultures. Lack of knowledge of these meanings, when overcoming huge distances, is no longer a problem, but it can lead to unpleasant misunderstandings. Such cultural meanings of color are also discussed.
Topics: Animals; Color; Color Perception; Color Vision; Color Vision Defects; Culture; Eye; Humans; Visual Cortex
PubMed: 31896397
DOI: 10.1016/j.clindermatol.2019.07.008 -
Clinical & Experimental Optometry Nov 2020Diagnosing colour vision deficiency is vital, owing to its impact on the choice of career and activities of daily living. Conventional screening methods require frequent...
BACKGROUND
Diagnosing colour vision deficiency is vital, owing to its impact on the choice of career and activities of daily living. Conventional screening methods require frequent replacement due to soiling of the materials, and hence are expensive and not feasible for large-scale community screening. This study aims to construct and validate a new screening tool, Dalton's pseudo-isochromatic plates (PIP), addressing the disadvantages of the conventional methods.
METHODS
The two phases of the study included the construction and validation of the Dalton's PIP. Construction involved utilising specific wavelengths based on spectral tuning, selection of numerals as targets for the chart and identification of a material with durability and resistance to wear and tear. Validation of the chart was done against the 38-plate edition of Ishihara's PIP by two masked examiners for 1,019 school children aged between 11-17 years (mean ± SD: 14 ± 2 years) as part of a school eye-health program.
RESULTS
The sensitivity and the specificity of the Dalton's PIP was found to be 94.12 per cent (95% CI 71.31-99.85) and 99.60 per cent (95% CI 98.98-99.89) respectively and the positive and negative predictive values were 80 per cent and 99.90 per cent respectively. Dalton's PIP when used with a failure criterion of less than three plates correct in two screening sets had the maximum sensitivity and specificity and the area under the curve was 0.96 (95% CI 0.90-0.99, p < 0.05).
CONCLUSION
The newly constructed Dalton's PIP is found to be a valid screening tool to detect congenital colour vision deficiency and is comparable to the Ishihara PIP. This screening tool with its shorter screening time, cost and longer durability would effectively serve in large-scale vision screening programs.
Topics: Activities of Daily Living; Adolescent; Child; Color Perception Tests; Color Vision Defects; Humans; Schools; Sensitivity and Specificity; Vision Screening
PubMed: 31845416
DOI: 10.1111/cxo.13034 -
The American Journal of Medicine May 2023
Topics: Humans; Color Vision Defects; Biomedical Research
PubMed: 36754131
DOI: 10.1016/j.amjmed.2023.01.019 -
Genetics in Medicine : Official Journal... Mar 2022This study aimed to systematically review and summarize gene therapy treatment for monogenic retinal and optic nerve diseases. (Review)
Review
PURPOSE
This study aimed to systematically review and summarize gene therapy treatment for monogenic retinal and optic nerve diseases.
METHODS
This review was prospectively registered (CRD42021229812). A comprehensive literature search was performed in Ovid MEDLINE, Ovid Embase, Cochrane Central, and clinical trial registries (February 2021). Clinical studies describing DNA-based gene therapy treatments for monogenic posterior ocular diseases were eligible for inclusion. Risk of bias evaluation was performed. Data synthesis was undertaken applying Synthesis Without Meta-analysis guidelines.
RESULTS
This study identified 47 full-text publications, 50 conference abstracts, and 54 clinical trial registry entries describing DNA-based ocular gene therapy treatments for 16 different genetic variants. Study summaries and visual representations of safety and efficacy outcomes are presented for 20 unique full-text publications in RPE65-mediated retinal dystrophies, choroideremia, Leber hereditary optic neuropathy, rod-cone dystrophy, achromatopsia, and X-linked retinoschisis. The most common adverse events were related to lid/ocular surface/cornea abnormalities in subretinal gene therapy trials and anterior uveitis in intravitreal gene therapy trials.
CONCLUSION
There is a high degree of variability in ocular monogenic gene therapy trials with respect to study design, statistical methodology, and reporting of safety and efficacy outcomes. This review improves the accessibility and transparency in interpreting gene therapy trials to date.
Topics: Color Vision Defects; Genetic Therapy; Humans; Optic Nerve Diseases; Retina; Retinal Dystrophies
PubMed: 34906485
DOI: 10.1016/j.gim.2021.10.013 -
Optics Letters Mar 2020We embed large-scale, plasmonic metasurfaces into off-the-shelf rigid gas permeable contact lenses and study their ability to serve as visual aids for color vision...
We embed large-scale, plasmonic metasurfaces into off-the-shelf rigid gas permeable contact lenses and study their ability to serve as visual aids for color vision deficiency. In this study, we specifically address deuteranomaly, which is the most common class of color vision deficiency. This condition is caused by a redshift of the medium-type cone photoreceptor and leads to ambiguity in the color perception of red and green and their combinations. The effect of the metasurface-based contact lenses on the color perception was simulated using Commission Internationale de l'Eclairage (CIE) color spaces and conventional models of the human color-sensitive photoreceptors. Comparison between normal color vision and uncorrected and corrected deuteranomaly by the proposed element demonstrates the ability offered by the nanostructured contact lens to shift back incorrectly perceived pigments closer to the original pigments. The maximal improvement in the color perception error before and after the proposed correction for deuteranomaly is up to a factor of $\sim{10}$∼10. In addition, an Ishihara-based color test was also simulated, showing the contrast restoration achieved by the element, for deuteranomaly conditions.
Topics: Coated Materials, Biocompatible; Color Perception; Color Perception Tests; Color Vision Defects; Computer Simulation; Contact Lenses; Equipment Design; Humans; Nanostructures; Optical Devices; Optical Phenomena; Sensory Aids; Spectrum Analysis; Surface Properties
PubMed: 32163975
DOI: 10.1364/OL.384970