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British Journal of Nursing (Mark Allen... Apr 2021
Topics: Color Vision Defects; Disabled Persons; Humans
PubMed: 33876691
DOI: 10.12968/bjon.2021.30.8.468 -
Optometry and Vision Science : Official... Feb 2023The Lanthony D15 has been reported to have poorer repeatability than the Farnsworth D15. This study found that two trials of the test provide high short-term... (Clinical Trial)
Clinical Trial
SIGNIFICANCE
The Lanthony D15 has been reported to have poorer repeatability than the Farnsworth D15. This study found that two trials of the test provide high short-term repeatability and can be administered this way for occupational testing.
PURPOSE
This study aimed to determine the short-term repeatability of the Lanthony D15 in patients with color vision deficiency. Repeated trials were used to examine if learning effects occur and to determine how many trials would be necessary to ensure the highest short-term repeatability for occupational testing.
METHODS
Twenty male subjects (mean [standard deviation] age, 27.2 [4.3] years) with congenital color vision deficiency, ranging from mild to severe, participated in this single-visit study. Visual acuity, color vision book screening, Farnsworth D15, and anomaloscope testing were performed for classification purposes. Ten trials of the Lanthony D15 were performed. Color confusion index scores from each trial were determined, and a repeated-measures analysis of variance was used to compare the scores across trials. Orthogonal polynomial analysis was performed to detect any trends across trials through the third order. The intraclass correlation coefficient was calculated.
RESULTS
No differences in color confusion index (mean [standard error of the mean], 3.57 [0.04]) were found across the 10 trials ( P = .18). Legendre polynomials showed no statistical significance (all P > .39). The intraclass correlation coefficient was 0.81 (95% confidence interval, 0.70 to 0.90). Based on the method of Shrout and Fleiss, intraclass correlation coefficients of 0.7, 0.8, and 0.9 could be achieved with an average of one, two, and four trials of the test, respectively. However, empirically, 0.9 was not achievable.
CONCLUSIONS
The Lanthony D15 test has fairly high short-term repeatability. Thus, although more trials would likely improve clinical certainty, the mean result of two trials appears sufficient for occupational testing.
Topics: Adult; Humans; Male; Color Perception; Color Perception Tests; Color Vision; Color Vision Defects; Vision Screening
PubMed: 36649587
DOI: 10.1097/OPX.0000000000001991 -
International Journal of Molecular... Feb 2021Achromatopsia (ACHM) is a rare genetic disorder of infantile onset affecting cone photoreceptors. To determine the extent of progressive retinal changes in... (Observational Study)
Observational Study
Achromatopsia (ACHM) is a rare genetic disorder of infantile onset affecting cone photoreceptors. To determine the extent of progressive retinal changes in achromatopsia, we performed a detailed longitudinal phenotyping and genetic characterization of an Italian cohort comprising 21 ACHM patients (17 unrelated families). Molecular genetic testing identified biallelic pathogenic mutations in known ACHM genes, including four novel variants. At baseline, the patients presented a reduced best corrected visual acuity (BCVA), reduced macular sensitivity (MS), normal dark-adapted electroretinogram (ERG) responses and undetectable or severely reduced light-adapted ERG. The longitudinal analysis of 16 patients (mean follow-up: 5.4 ± 1.0 years) showed a significant decline of BCVA (0.012 logMAR/year) and MS (-0.16 dB/year). Light-adapted and flicker ERG responses decreased below noise level in three and two patients, respectively. Only two patients (12.5%) progressed to a worst OCT grading during the follow-up. Our findings corroborate the notion that ACHM is a progressive disease in terms of BCVA, MS and ERG responses, and affects slowly the structural integrity of the retina. These observations can serve towards the development of guidelines for patient selection and intervention timing in forthcoming gene replacement therapies.
Topics: Adolescent; Adult; Biomarkers; Child, Preschool; Color Vision Defects; Cyclic Nucleotide Phosphodiesterases, Type 6; Cyclic Nucleotide-Gated Cation Channels; DNA Mutational Analysis; Eye Proteins; Female; Heterotrimeric GTP-Binding Proteins; Humans; Longitudinal Studies; Male; Mutation; Pedigree; Phenotype; Prognosis; Retrospective Studies; Tomography, Optical Coherence; Young Adult
PubMed: 33562422
DOI: 10.3390/ijms22041681 -
Eye (London, England) Aug 2021In the absence of pre-admission testing for colour blindness, many of the currently practicing ophthalmologists are colour blind, accordingly their accuracy of...
PURPOSE
In the absence of pre-admission testing for colour blindness, many of the currently practicing ophthalmologists are colour blind, accordingly their accuracy of distinguishing fine diabetic retinopathy (DR) changes is still unknown. This study aims to assess the accuracy of diagnosing and staging diabetic retinopathy and macular oedema among protonopic, deutronopic and tritanopic ophthalmologists.
METHODS
Cross-sectional assessment of fundus images that were prepared to simulate the appearance in cases of colour blindness. We assessed the accuracy of staging diabetic retinopathy and macular oedema by a retina specialist on colour-blind simulated images. We used randomiser.org to randomly select images to be simulated by the previously validated Vischeck colour blindness simulator.
RESULTS
A total of 150 simulated images were reviewed, 50 images for each of simulated protanopia, deuteranopia and tritanopia. We found that the accuracy for staging DR and macular oedema for protanope grader were 50% and 60%, respectively. Accuracy within one stage difference for DR and macular oedema were 88% and 90%, respectively. For deuteranopes, 56% and 64% accuracy for DR and macular oedema, respectively. Accuracy within one stage difference for DR and macular oedema were 86% and 90%, respectively. For Tritanope, 62% and 84% accuracy for DR and macular oedema, respectively.
CONCLUSION
Colour vision is important for distinguishing fine details during retina assessment in diabetic retinopathy patients. Colour blindness is associated with low accuracy in staging diabetic retinopathy and macular oedema, particularly among protonopic graders, and to a lesser extent in tritanopic graders.
Topics: Color; Color Vision Defects; Cross-Sectional Studies; Diabetes Mellitus; Diabetic Retinopathy; Humans; Ophthalmologists
PubMed: 33106610
DOI: 10.1038/s41433-020-01232-z -
Scientific Reports Feb 2022Color blindness, or color vision deficiency (CVD), is an ocular disease that suppresses the recognition of different colors. Recently, tinted glasses and lenses have...
Color blindness, or color vision deficiency (CVD), is an ocular disease that suppresses the recognition of different colors. Recently, tinted glasses and lenses have been studied as hopeful devices for color blindness correction. In this study, 2D biocompatible and flexible plasmonic contact lenses were fabricated using polydimethylsiloxane (PDMS) and a low-cost, and simple design based on the soft nano-lithography method and investigated for correction of red-green (deuteranomaly) color blindness. In addition, the stability test of the fabricated plasmonic contact lenses was investigated into the phosphate buffered saline (PBS) solution and the proposed lens offers an excellent stability into the PBS solution. The plasmonic contact lens proposed herein is based on the plasmonic surface lattice resonance (SLR) phenomenon and offers a good color filter for color blindness correction. The biocompatibility, low cost, stability, and simple fabrication of these contact lenses can offer new insights for applications of color blindness correction.
Topics: Biocompatible Materials; Buffers; Color; Color Perception; Color Vision Defects; Contact Lenses; Dimethylpolysiloxanes; Humans; Phosphates; Pliability; Saline Solution; Vision, Ocular
PubMed: 35132172
DOI: 10.1038/s41598-022-06089-8 -
Journal of Medical Genetics Dec 2017Throughout Earth's history, evolution's numerous natural 'experiments' have resulted in a diverse range of phenotypes. Though de novo phenotypes receive widespread... (Review)
Review
Throughout Earth's history, evolution's numerous natural 'experiments' have resulted in a diverse range of phenotypes. Though de novo phenotypes receive widespread attention, degeneration of traits inherited from an ancestor is a very common, yet frequently neglected, evolutionary path. The latter phenomenon, known as regressive evolution, often results in vertebrates with phenotypes that mimic inherited disease states in humans. Regressive evolution of anatomical and/or physiological traits is typically accompanied by inactivating mutations underlying these traits, which frequently occur at loci identical to those implicated in human diseases. Here we discuss the potential utility of examining the genomes of vertebrates that have experienced regressive evolution to inform human medical genetics. This approach is low cost and high throughput, giving it the potential to rapidly improve knowledge of disease genetics. We discuss two well-described examples, rod monochromacy (congenital achromatopsia) and amelogenesis imperfecta, to demonstrate the utility of this approach, and then suggest methods to equip non-experts with the ability to corroborate candidate genes and uncover new disease loci.
Topics: Amelogenesis Imperfecta; Animals; Color Vision Defects; Evolution, Molecular; Genetic Association Studies; Genetic Loci; Genetic Predisposition to Disease; Genome; Genomics; Humans; Models, Genetic; Mutation; Phenotype; Pseudogenes; Vertebrates
PubMed: 28814606
DOI: 10.1136/jmedgenet-2017-104837 -
Scientific Reports May 2022We set out to develop a simple objective test of functional colour vision based on eye movements made in response to moving patterns. We exploit the finding that while...
We set out to develop a simple objective test of functional colour vision based on eye movements made in response to moving patterns. We exploit the finding that while the motion of a colour-defined stimulus can be cancelled by adding a low-contrast luminance-defined stimulus moving in the opposite direction, the "equivalent luminance contrast" required for such cancellation is reduced when colour vision is abnormal. We used a consumer-grade infrared eye-tracker to measure eye movements made in response to coloured patterns drifting at different speeds. An automated analysis of these movements estimated individuals' red-green equiluminant point and their equivalent luminance contrast. We tested 34 participants: 23 colour vision normal controls, 9 deuteranomalous and 2 protanomalous individuals. We obtained reliable estimates of strength of directed eye movements (i.e. combined optokinetic and voluntary tracking) for stimuli moving at 16 deg/s and could use these data to classify participants' colour vision status with a sensitivity rate of 90.9% and a specificity rate of 91.3%. We conclude that an objective test of functional colour vision combining a motion-nulling technique with an automated analysis of eye movements can diagnose and assess the severity of protanopia and deuteranopia. The test places minimal demands on patients (who simply view a series of moving patterns for less than 90 s), requires modest operator expertise, and can be run on affordable hardware.
Topics: Color Perception; Color Vision; Color Vision Defects; Contrast Sensitivity; Eye Movements; Humans; Motion Perception
PubMed: 35562176
DOI: 10.1038/s41598-022-11152-5 -
Military Medicine Jan 2023Color vision deficiency (CVD) is a disqualifying condition for military special duty occupations. Color vision testing and standards vary slightly among the U.S....
INTRODUCTION
Color vision deficiency (CVD) is a disqualifying condition for military special duty occupations. Color vision testing and standards vary slightly among the U.S. military branches. Paper-based pseudoisochromatic plates (PIPs) remain a screening tool. Computer-based color vision tests (CVTs), i.e., the Cone Contrast Test (CCT), the Colour Assessment and Diagnosis (CAD) test, and the Waggoner Computerized Color Vision Test (WCCVT), are now replacing the Farnsworth Lantern Test (FALANT) and its variants to serve as a primary or secondary test in the U.S. Armed Forces. To maintain consistency in recruitment, performance, and safety, the study objectives were to examine military color vision testing, passing criteria, and color discrimination performance.
METHODS
Study participants were 191 (17% female) students, faculty, and staff of the U.S. Air Force Academy and the Naval Aerospace Medical Institute. All subjects performed six CVTs, and 141 participants completed two additional military relevant color discrimination tasks. Friedman non-parametric test and Wilcoxon signed-rank post hoc test with Bonferroni adjusted P values were used to compare CVTs and standards. Analysis of variance and Bonferroni adjusted post hoc test were used to describe effects on color discrimination performance.
RESULTS
The Heidelberg Multicolor-Moreland and Rayleigh (HMC-MR) anomaloscope diagnosed 58 CVD (30.4%). There were no statistically significant differences in identifying red-green CVD by the HMC-MR, CCT, CAD, WCCVT, and PIP tests (P = .18), or classifying deutan, protan, and normal color vision (CVN) by the HMC-MR and the CVT (P = .25). Classification of tritan CVD was significantly different depending on which CVT was used (P < .001). Second, overall passing rates were 79.1% on the CAD (≤6 standard normal unit (SNU)), 78.5% on the combined PIP/FALANT, 78.0% on the CCT (≥55%), and 75.4% on the WCCVT (mild) military standards. The CVTs and the PIP/FALANT standards were not significantly different in number of personnel selected, but CAD and CCT passed significantly more individuals than WCCVT (P = .011 and P = .004, respectively). The previous U.S. Air Force standard (CCT score ≥75%) passed significantly fewer individuals relative the U.S. Navy pre-2017 PIP/FALANT or the current CVT standards (P ≤ .001). Furthermore, for those who failed the PIP (<12/14), the FALANT (9/9 or ≥16/18) agreed with the CVTs on passing the same CVN (n = 5); however, it also passed moderate-to-severe CVD who did not pass WCCVT (n = 6), CCT (n = 3), and CAD (n = 1). Lastly, moderate/severe CVD were significantly slower and less accurate than the "mild" CVD or CVN in the two color discrimination tasks (P < .001). In comparison to CVN in the in-cockpit display color discrimination task, mild CVD (CCT ≥55% and <75%) were significantly slower by 1,424 ± 290 milliseconds in reaction time (P < .001) while maintaining accuracy.
CONCLUSIONS
CVTs are superior to paper-based PIP in diagnosing, classifying, and grading CVD. Relative to the PIP/FALANT standard in personnel selection, the current U.S. military CVT passing criteria offer comparable passing rates but are more accurate in selecting mild CVD. Nevertheless, military commanders should also consider specific operational requirements in selecting mild CVD for duty as reduced job performance may occur in a complex color critical environment.
Topics: Humans; Female; Male; Color Vision; Color Perception Tests; Military Personnel; Color Vision Defects; Cardiovascular Diseases
PubMed: 35352814
DOI: 10.1093/milmed/usac080 -
Methods in Molecular Biology (Clifton,... 2018Achromatopsia (ACHM) and retinitis pigmentosa (RP) are inherited disorders caused by mutations in cone and rod photoreceptor-specific genes, respectively. ACHM strongly...
Achromatopsia (ACHM) and retinitis pigmentosa (RP) are inherited disorders caused by mutations in cone and rod photoreceptor-specific genes, respectively. ACHM strongly impairs daylight vision, whereas RP initially affects night vision and daylight vision at later stages. Currently, gene supplementation therapies utilizing recombinant adeno-associated virus (rAAV) vectors are being developed for various forms of ACHM and RP. In this chapter, we describe the procedure of designing and developing specific and efficient rAAV vectors for cone- and rod-specific gene supplementation.
Topics: Color Vision Defects; Dependovirus; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; HEK293 Cells; Humans; Plasmids; Retinitis Pigmentosa
PubMed: 29188504
DOI: 10.1007/978-1-4939-7522-8_3 -
Optometry and Vision Science : Official... Feb 2015
Topics: Accidents; Color Perception Tests; Color Vision; Color Vision Defects; Health Occupations; History, 19th Century; Humans; Railroads; Sweden
PubMed: 25951474
DOI: 10.1097/OPX.0000000000000519