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ACS Nano Mar 2021Color vision deficiency (CVD) is an ocular congenital disorder that affects 8% of males and 0.5% of females. The most prevalent form of color vision deficiency (color...
Color vision deficiency (CVD) is an ocular congenital disorder that affects 8% of males and 0.5% of females. The most prevalent form of color vision deficiency (color blindness) affects protans and deutans and is more commonly known as "red-green color blindness". Since there is no cure for this disorder, CVD patients opt for wearables that aid in enhancing their color perception. The most common wearable used by CVD patients is a form of tinted glass/lens. Those glasses filter out the problematic wavelengths (540-580 nm) for the red-green CVD patients using organic dyes. However, few studies have addressed the fabrication of contact lenses for color vision deficiency, and several problems related to their effectiveness and toxicity were reported. In this study, gold nanoparticles are integrated into contact lens material, thus forming nanocomposite contact lenses targeted for red-green CVD application. Three distinct sets of nanoparticles were characterized and incorporated with the hydrogel material of the lenses (pHEMA), and their resulting optical and material properties were assessed. The transmission spectra of the developed nanocomposite lenses were analogous to those of the commercial CVD wearables, and their water retention and wettability capabilities were superior to those in some of the commercially available contact lenses used for cosmetic/vision correction purposes. Hence, this work demonstrates the potential of gold nanocomposite lenses in CVD management and, more generally, color filtering applications.
Topics: Color; Color Vision Defects; Contact Lenses; Female; Gold; Humans; Male; Metal Nanoparticles; Nanocomposites
PubMed: 33570901
DOI: 10.1021/acsnano.0c09657 -
Genes Jul 2021Light absorption by photopigment molecules expressed in the photoreceptors in the retina is the first step in seeing. Two types of photoreceptors in the human retina are... (Review)
Review
Light absorption by photopigment molecules expressed in the photoreceptors in the retina is the first step in seeing. Two types of photoreceptors in the human retina are responsible for image formation: rods, and cones. Except at very low light levels when rods are active, all vision is based on cones. Cones mediate high acuity vision and color vision. Furthermore, they are critically important in the visual feedback mechanism that regulates refractive development of the eye during childhood. The human retina contains a mosaic of three cone types, short-wavelength (S), long-wavelength (L), and middle-wavelength (M) sensitive; however, the vast majority (~94%) are L and M cones. The and genes, located on the X-chromosome at Xq28, encode the protein component of the light-sensitive photopigments expressed in the L and M cones. Diverse haplotypes of exon 3 of the and genes arose thru unequal recombination mechanisms that have intermixed the genes. A subset of the haplotypes causes exon 3- skipping during pre-messenger RNA splicing and are associated with vision disorders. Here, we review the mechanism by which splicing defects in these genes cause vision disorders.
Topics: Exons; Haplotypes; Humans; RNA Splicing; Retina; Rod Opsins; Vision Disorders
PubMed: 34440353
DOI: 10.3390/genes12081180 -
Clinical & Experimental Optometry Jul 2016Studies have shown considerable evidence of visual dysfunction in autism spectrum disorders. Anomalies in visual information processing can have a major effect on the... (Review)
Review
Studies have shown considerable evidence of visual dysfunction in autism spectrum disorders. Anomalies in visual information processing can have a major effect on the life quality of individuals with autism spectrum disorders. We summarise the hypotheses and theories underlying neural aetiologies and genetic factors that cause these disorders, as well as the possible influences of unusual sensory processing on the communications and behaviour characterised by the autistics. In particular, we review the impact of these dysfunctions on visual performance.
Topics: Autism Spectrum Disorder; Brain; Color Vision Defects; Contrast Sensitivity; Depth Perception; Epigenesis, Genetic; Humans; Ocular Motility Disorders; Refractive Errors; Vision Disorders; Vision, Ocular; Visual Fields
PubMed: 27161596
DOI: 10.1111/cxo.12383 -
Investigative Ophthalmology & Visual... Apr 2023Specific haplotypes (LVAVA, LIVVA, and LIAVA) formed by five polymorphisms (p.L153M, p.V171I, p.A174V, p.I178V, and p.S180A in exon 3 of OPN1LW) that cause partial or...
PURPOSE
Specific haplotypes (LVAVA, LIVVA, and LIAVA) formed by five polymorphisms (p.L153M, p.V171I, p.A174V, p.I178V, and p.S180A in exon 3 of OPN1LW) that cause partial or complete exon skipping have been reported as unique genetic causes of high myopia with or without colorblindness. This study aimed to identify the contribution of OPN1LW to early-onset high myopia (eoHM) and the molecular basis underlying eoHM with or without colorblindness.
METHODS
Comparative analysis of exome sequencing data was conducted for 1226 families with eoHM and 9304 families with other eye conditions. OPN1LW variants detected by targeted or whole exome sequencing were confirmed by long-range amplification and Sanger sequencing, together with segregation analysis. The clinical data were thoroughly analyzed.
RESULTS
Unique haplotypes and truncation variants in OPN1LW were detected exclusively in 68 of 1226 families with eoHM but in none of the 9304 families with other visual diseases (P = 1.63 × 10-63). Four classes of variants were identified: haplotypes causing partial splicing defects in OPN1LW (LVAVA or LIVVA in 31 families), LVAVA in OPN1LW-OPN1MW hybrid gene (in 3 families), LIAVA in OPN1LW (in 29 families), and truncations in OPN1LW (in 5 families). The first class causes partial loss of red photopigments, whereas the latter three result in complete loss of red photopigments. This is different from the replacement of red with green owing to unequal re-arrangement causing red-green colorblindness alone. Of the 68 families, 42 affected male patients (31 families) with the first class of variants (LVAVA or LIVVA in OPN1LW) had eoHM alone, whereas 37 male patients with the latter 3 classes had eoHM with protanopia. Adaptive optics retinal imaging demonstrated reduced cone regularity and density in men with eoHM caused by OPN1LW variants compared to those patients with eoHM and without OPN1LW variants.
CONCLUSION
Based on the 68 families with unique variants in OPN1LW, our study provides firm evidence that the two different phenotypes (eoHM with or without colorblindness) are caused by two different classes of variants (partial splicing-effect haplotypes or complete splicing-effect haplotypes/truncation variants, respectively). The contribution of OPN1LW to eoHM (isolated and syndromic) was characterized by OPN1LW variants found in 5.5% (68/1226) of the eoHM families, making it the second most common cause of monogenic eoHM alone (2.4%) and a frequent cause of syndromic monogenic eoHM with colorblindness. Such haplotypes, in which each individual variant alone is considered a benign polymorphism, are potential candidates for other hereditary diseases with causes of missing genetic defects.
Topics: Humans; Male; Color Vision Defects; Haplotypes; Mutation; Myopia; Pedigree
PubMed: 37097228
DOI: 10.1167/iovs.64.4.29 -
Current Research in Food Science Jun 2020Visual perception plays a key role in the selection of nutritious and healthy foods. Color, as one of the most important senses of vision, can be used as an indicator of...
Visual perception plays a key role in the selection of nutritious and healthy foods. Color, as one of the most important senses of vision, can be used as an indicator of food quality/defects and grade. It is recommended consumers include various colors in their plate to obtain various vitamins and minerals. Color is also thought to be related to antioxidant capacity. Within this regard, this study investigated the relationship between color and antioxidant capacity in various fruits and vegetables. The results indicate the color hues analyzed by computer vision based image analysis can be related with TAC of fruits and vegetables, but with some limitations and can be used as a guide for food selection to increase daily antioxidant intake. Most of fruits and vegetables having hue values above 180° and below 20°, have high antioxidant capacity (>10 mmol TE/kg fresh weight). The results also emphasized the importance of the serving size of fruits and vegetables in terms of their contribution to daily antioxidant intake. Based on these results, fruits and vegetables could be categorized into low-, medium-, and high-antioxidant groups according to their TAC and potential contributions to fulfill the recommended daily antioxidant intake. Finally, daily antioxidant intake was evaluated with a healthier scenario created by doubling vegetable portion and reducing fruit portion by half in the meal.
PubMed: 32914105
DOI: 10.1016/j.crfs.2019.11.001 -
Proceedings of the National Academy of... Jul 2015Around 2% of males have red-green dichromacy, which is a genetic disorder of color vision where one type of cone photoreceptor is missing. Here we investigate the color...
Around 2% of males have red-green dichromacy, which is a genetic disorder of color vision where one type of cone photoreceptor is missing. Here we investigate the color preferences of dichromats. We aim (i) to establish whether the systematic and reliable color preferences of normal trichromatic observers (e.g., preference maximum at blue, minimum at yellow-green) are affected by dichromacy and (ii) to test theories of color preference with a dichromatic sample. Dichromat and normal trichromat observers named and rated how much they liked saturated, light, dark, and focal colors twice. Trichromats had the expected pattern of preference. Dichromats had a reliable pattern of preference that was different to trichromats, with a preference maximum rather than minimum at yellow and a much weaker preference for blue than trichromats. Color preference was more affected in observers who lacked the cone type sensitive to long wavelengths (protanopes) than in those who lacked the cone type sensitive to medium wavelengths (deuteranopes). Trichromats' preferences were summarized effectively in terms of cone-contrast between color and background, and yellow-blue cone-contrast could account for dichromats' pattern of preference, with some evidence for residual red-green activity in deuteranopes' preference. Dichromats' color naming also could account for their color preferences, with colors named more accurately and quickly being more preferred. This relationship between color naming and preference also was present for trichromat males but not females. Overall, the findings provide novel evidence on how dichromats experience color, advance the understanding of why humans like some colors more than others, and have implications for general theories of aesthetics.
Topics: Color; Color Perception; Color Vision; Color Vision Defects; Colorimetry; Female; Humans; Male; Multivariate Analysis; Psychophysics; Reproducibility of Results; Retinal Cone Photoreceptor Cells
PubMed: 26170287
DOI: 10.1073/pnas.1502104112 -
Experimental Eye Research Jul 2022The purpose of this study was to establish spectral domain optical coherence tomography (SD-OCT) assessment data in well-established canine models of inherited retinal...
Quantitative and qualitative characterization of retinal dystrophies in canine models of inherited retinal diseases using spectral domain optical coherence tomography (SD-OCT).
The purpose of this study was to establish spectral domain optical coherence tomography (SD-OCT) assessment data in well-established canine models of inherited retinal dystrophies: PDE6B-rod-cone dysplasia 1 (RCD1: early onset retinitis pigmentosa), PRCD-progressive rod-cone degeneration (PRCD: late onset retinitis pigmentosa), CNGB3-achromatopsia, and RPE65-Leber congenital amaurosis (LCA). High resolution SD-OCT images of the retina were acquired from both eyes in 5 planes: temporal; superotemporal; superior; nasal; and inferior in adult dogs with: RCD1 (n = 4 dogs, median age: 1.5 yrs); PRCD (n = 2, 4.3 yrs); LCA (n = 3, 5.2 yrs); achromatopsia (n = 3, 4.2 yrs); and wild types (wt, n = 6, 5.5 yrs). Total, inner and outer retinal thicknesses and ellipsoid zone were analyzed. In selected animals, histomorphometric evaluations were performed. In dogs with RCD1, PRCD, and LCA, the thickness of the outer retina was, compared to wt, significantly decreased (p ≤ 0.02) in all OCT imaging planes, and in superotemporal and inferior imaging planes in dogs with achromatopsia. No significant thinning was observed in inner retina thickness in any disease model except in the inferior imaging plane in dogs with RCD1. Dogs with RCD1, PRCD, and LCA had significantly more areas with disrupted ellipsoid zone in the presumed area centralis than wt (p ≤ 0.001). OCT findings provide baseline information for research of retinal dystrophies using these canine models.
Topics: Animals; Color Vision Defects; Dogs; Retina; Retinal Dystrophies; Retinitis Pigmentosa; Tomography, Optical Coherence
PubMed: 35588783
DOI: 10.1016/j.exer.2022.109106 -
Romanian Journal of Ophthalmology 2021This article represents an engagement between ophthalmology, culture, art, and knowledge. The paper reviews numerous ophthalmic pathologies that affected some of the... (Review)
Review
This article represents an engagement between ophthalmology, culture, art, and knowledge. The paper reviews numerous ophthalmic pathologies that affected some of the most famous artists from all the time. The style of a painting can be created on purpose by the artist, but it can also be affected by the visual acuity. The most significant ocular diseases that might affect visual acuity and style of painting are represented by strabismus, refractive errors, cataract, retinal diseases, color vision deficiency and ocular trauma. During the time, various styles of paintings could be encountered and, very often, we wondered whether the style is influenced by the visual acuity of the artists or visual acuity does not affect at all the styles. The purpose of this study was to prove how ocular pathologies might have affected art creation during the past centuries.
Topics: Color Vision Defects; Humans; Ophthalmology; Paintings; Retinal Diseases; Strabismus
PubMed: 35087973
DOI: 10.22336/rjo.2021.67 -
Translational Vision Science &... Jun 2020To examine repeatability and reproducibility of foveal cone density measurements in patients with and -associated achromatopsia (ACHM) using split-detection adaptive...
PURPOSE
To examine repeatability and reproducibility of foveal cone density measurements in patients with and -associated achromatopsia (ACHM) using split-detection adaptive optics scanning light ophthalmoscopy (AOSLO).
METHODS
Thirty foveae from molecularly confirmed subjects with ACHM, half of whom harbored disease-causing variants in and half in underwent nonconfocal split-detection AOSLO imaging. Cone photoreceptors within the manually delineated rod-free zone were manually identified twice by two independent observers. The coordinates of the marked cones were used for quantifying foveal cone density. Cone density and difference maps were generated to compare cone topography between trials.
RESULTS
We observed excellent intraobserver repeatability in foveal cone density estimates, with intraclass correlation coefficients (ICCs) ranging from 0.963 to 0.991 for and subjects. Interobserver reproducibility was also excellent for both (ICC = 0.952; 95% confidence interval [CI], 0.903-1.0) and (ICC = 0.968; 95% CI, 0.935-1.0). However, Bland-Altman analysis revealed bias between observers.
CONCLUSIONS
Foveal cone density can be measured using the described method with good repeatability and reproducibility both for - and -associated ACHM. Any degree of bias observed among the observers is of uncertain clinical significance but should be evaluated on a study-specific basis.
TRANSLATIONAL RELEVANCE
This approach could be used to explore disease natural history, as well as to facilitate stratification of patients and monitor efficacy of interventions for ongoing and upcoming ACHM gene therapy trials.
Topics: Color Vision Defects; Cyclic Nucleotide-Gated Cation Channels; Fovea Centralis; Humans; Reproducibility of Results; Retinal Cone Photoreceptor Cells
PubMed: 32832242
DOI: 10.1167/tvst.9.7.37 -
International Ophthalmology Dec 2020Visual electrophysiological testing continues to generate interest among glaucoma experts because of its potential help in clarifying disease pathophysiology and... (Review)
Review
PURPOSE
Visual electrophysiological testing continues to generate interest among glaucoma experts because of its potential help in clarifying disease pathophysiology and promoting early detection of glaucomatous damage. The photopic negative response (PhNR) is a slow negative component of the full-field electroretinogram that has been shown to provide specific information about retinal ganglion cells (RGCs) activity. The purpose of this article is to review the literature to explore the currently available measurement methods and the utility of PhNR in glaucoma diagnostic process.
METHODS
We gathered publications related to the origins, types of stimuli used, measurements methods and applications of the PhNR of ERG in animal models and humans through a search of the literature cited in PubMed. Search terms were: "PhNR", "photopic negative response", "glaucoma", "glaucomatous optic neuropathy", "ERG", "electroretinogram".
RESULTS
The most reliable PhNR measurements are obtained using a red stimulus on a blue background, without requiring refractive correction, fixation monitoring, or ocular media transparency. Given its direct correlation with RGCs response, the PhNR measured as baseline-to-trough (BT) represents the most reliable parameter of evaluation. Glaucoma patients with evident perimetric defects show pathologic PhNR values. Even though the PhNR is promising in detecting early RGCs impairment, distinguishing between healthy subjects and suspect patients at risk of developing glaucomatous damage still remains challenging.
CONCLUSION
The PhNR is a useful additional tool to explore disorders that affect the innermost retina, including glaucoma and other forms of optic neuropathy. In particular, comparing reports of the standard examinations (optic disc assessment, OCT RNFL measurement, standard automated perimetry) with the results of electrophysiological tests may be helpful in solving clinical diagnostic and management dilemmas. On the one hand, the PhNR of the ERG can examine the parvocellular pathways; on the other hand, the steady-state pattern ERG optimized for glaucoma screening (PERGLA) can explore the magnocellular pathways. This could give ophthalmologists a useful feedback to identify early RGCs alterations suggestive of glaucoma, stratify the risk and potentially monitor disease progression.
Topics: Animals; Color Vision; Electroretinography; Glaucoma; Humans; Photic Stimulation; Retinal Ganglion Cells
PubMed: 32737731
DOI: 10.1007/s10792-020-01515-0