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Color vision deficiency
Abstract and Figures
Colour vision deficiency is one of the commonest disorders of vision and can be divided into congenital and acquired forms. Congenital colour vision deficiency affects as many as 8% of males and 0.5% of females--the difference in prevalence reflects the fact that the commonest forms of congenital colour vision deficiency are inherited in an X-linked recessive manner. Until relatively recently, our understanding of the pathophysiological basis of colour vision deficiency largely rested on behavioural data; however, modern molecular genetic techniques have helped to elucidate its mechanisms. The current management of congenital colour vision deficiency lies chiefly in appropriate counselling (including career counselling). Although visual aids may be of benefit to those with colour vision deficiency when performing certain tasks, the evidence suggests that they do not enable wearers to obtain normal colour discrimination. In the future, gene therapy remains a possibility, with animal models demonstrating amelioration following treatment.
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... Color vision deficiency (CVD) is the inability or decreased ability to perceive color differences [1,2]. The condition primarily affects males due to its X-linked inheritance pattern [3,4], but it can also occur as a result of an ocular, neurologic, or systemic cause [5]. ...
... In Europe, a single study reported a prevalence of 7.33% [9], and a study from Asia found a prevalence of 6.8% [11], which only included male participants. This might be a possible reason for the higher prevalence, as color vision deficiency is linked to the X linked inheritance pattern and is more prevalent in men [2]. ...
Background
Color vision deficiency (CVD) cause is the difficulty distinguishing colors, which can present vocational and avocational challenges. There is a lack of data on its overall prevalence of CVD. Therefore, this systematic review and meta-analysis aim to determine the prevalence of CVD in Africa.
Methods
The protocol was registered with the Prospective Register of Systematic Reviews (PROSPERO) database (protocol registration number: CRD42024510403). A comprehensive systematic literature search was conducted via PubMed/MEDLINE/EMBASE, Google, and Google Scholar from February 2024 to May 28, 2024. The Johanna Bridges Institute quality appraisal tool was used to assess the quality of eligible articles. The pooled prevalence of CVD among Africans was estimated using a random effect model and expressed as prevalence and odds ratios with 95% confidence intervals using Der Simonian-Laird weight. The I² statistic test was used to measure heterogeneity, and subgroup analysis was performed based on country, source of population, and gender.
Result
A total of 502 initial studies were identified, and sixteen cross-sectional studies were included. The overall pooled prevalence of CVD in Africa was 2.71% (95% CI: 2.28,3.14, I² = 72.6%, P<0.001). The prevalence among African males and females was 2.13% and 0.34%, respectively. The highest pooled prevalence was recorded in Ethiopia at 3.63% and the prevalence among primary and secondary school students was 2.96%. A funnel plot showed that all of the studies were symmetric, and the Egger test showed no publication bias.
Conclusion
The pooled prevalence of color vision deficiency in Africa was found to be 2.71%. The highest prevalence was reported in studies conducted among school-age children in Ethiopia. Establishing effective screening programs and raising public awareness are recommended as future steps.
... According to the "Guiding Opinions on Physical Examination for Enrollment in Ordinary Colleges and Universities, " more than 50 professions are restricted to individuals with CVD. Consequently, people with CVD are excluded from certain professions such as the military, aviation, and specific medical fields (8,9), due to their distinct disadvantage in performing visual tasks (10). As a result, CVD significantly impacts people's daily lives, hindering them from achieving their goals and ambitions (11,12). ...
Purpose
This study presents a novel randomized controlled trial investigating photobiomodulation (PBM) therapy as an intervention method for color vision deficiency (CVD).
Methods
A total of 74 participants with CVD were assigned to either the PBM group or the control group. In the PBM group, participants wore virtual reality (VR) goggles twice daily, with a 12-h interval, over a four-week period. The VR video consisted of alternating red and green images, each presented for 5 s, totaling 6 min and 20 s. No treatment was administered to the control group. Color vision improvement was assessed using Yu’s, Ishihara’s pseudoachromatic plates, Color Blindness Check (CBC), and FM-100 Hue total error score (TES).
Results
After 4 weeks, in terms of Yu’s and Ishihara’s Plates, the patients in PBM group could identify increasing pieces (before: 1.6 ± 1.6, 2.3 ± 2.2; 4 weeks: 6.5 ± 4.4, 5.4 ± 2.9), while in control group, the number was before: 2.6 ± 3.4, 2.6 ± 2.5; 4 weeks: 3.3 ± 3.6, 2.9 ± 2.2. As for CBC scores, the patients in PBM also showed improved high scores (before: 2353.3 ± 700.0; 4 weeks: 2693.6 ± 642.5). Moreover, PBM treatment resulted in a significant reduction of FM-100 scores (before: 298.0 ± 211.3; 4 weeks: 202.1 ± 114.4).
Conclusion
These findings suggest that PBM therapy holds promise as a potential treatment option for individuals with CVD.
Clinical trial registration
The study received approval from the Ethics Committee of PLA General Hospital, China (KY2021-017). Additionally, it was registered as a Chinese domestic clinical trial (ChiCTR2200056761) at “http://Chictr.org.cn/index.aspx”.
... Unfortunately, with the current data, it is not possible to determine whether the lower cone density we found in our patients with DM is representative of cone absence or simply lack of waveguiding outer segments, 42 as not all cones could be resolved using non-confocal imaging. However, the accompanying changes in intercell regularity suggest some extent of cone loss. ...
Purpose
Although it is well known that photoreceptor damage and color vision loss occur in patients with diabetic retinopathy (DR), the relationship between structural and functional changes in diabetes mellitus (DM) remains unclear. Using highly sensitive measures of photoreceptor structure and function, we aim to determine whether early loss of color sensitivity in DM is also accompanied by decreased cone density.
Methods
Monocular data from 26 patients with DM and 25 healthy controls were examined to assess cone photoreceptor metrics, using confocal adaptive optics scanning light ophthalmoscopy, and red/green (RG) and yellow/blue (YB) color vision thresholds, using the Colour Assessment and Diagnosis test.
Results
Both RG and YB thresholds were significantly greater in patients with DM than in the healthy controls (RG and YB = P < 0.001), and there were statistically significant differences between the 2 groups in confocal cone density at 1 degree (P = 0.024), and intercell regularity at both 1 (P = 0.013) and 2 degrees (P = 0.012). In patients with DM, cone density was inversely correlated with YB (at 0.5, 1 and 2 degrees, all P values < 0.041), but not for RG color vision thresholds.
Conclusions
This is the first study to investigate the relationship between cone metrics and color vision in patients with DM. The results reveal a significant inverse relationship between confocal cone density and color vision thresholds at the locations assessed within the foveal region. These findings represent a significant advancement in oculomics research.
This study investigates colour vision deficits in children with amblyopia by employing a computerized colour vision test with varying stimulus sizes (1°, 2°, and 3°). The aim is to delineate the impact of amblyopia on colour discrimination in children and to determine the effectiveness of the computerized colour vision test in detecting these deficits. The study involved 40 participants, divided into 20 children with amblyopia and 20 without amblyopia (control group). Our findings reveal that, during binocular viewing, children with amblyopia exhibit significant impairments in colour vision both for red–green and blue–yellow axes, primarily for 1° chromatic stimuli, but not for larger stimuli (2° and 3°). These findings offer valuable insight into the functional visual limitations in pediatric amblyopia, potentially guiding more targeted clinical assessments and interventions.
Color blindness, also known as color vision deficiency (CVD), is a prevalent ocular disorder that hinders distinguishing different colors, a challenge experienced by a considerable portion of the global population (8−10% of males and 0.4−0.5% of females). CVD patients are frequently restricted from crucial professions such as military or police, and cannot recognize colors in public places or media like watching TV. Despite ongoing efforts, there is no definitive cure for color blindness; however, various color filter-based devices such as tinted glasses and contact lenses have been introduced to assist CVD people. Recently, plasmonic nanostructures have attracted significant attention for CVD management by replacing chemical dyes due to their outstanding properties and the adjustability of plasmonic resonances. This study reviews the different wearables utilized in CVD management, such as eyeglasses and contact lenses, with a special emphasis on the innovative plasmonic eye wearables that have emerged in recent advances. The capability to modify the plasmonic properties by manipulating their morphology provides novel perspectives for CVD management and smart ophthalmic wearables.
The dark red X-chrome lens, which can be worn on the nondominant eye of a person with color vision deficiency (CVD), is said to enhance color perception. We hereby report two cases of hereditary CVD in patient who had difficulty differentiating colors and had a problem with their daily tasks. The first case presented with 20/20 visual acuity (VA) with N6 in both eyes (BE) and could read 7 and 6 plates in the right eye (RE) and left eye (LE). In the second case, with a VA of 20/40 and N6 in BE, he appreciated 4 and 5 plates in RE and LE on Ishihara plates. Both cases improved to 20/25 plates after the insertion of the X-chrome lens. In conclusion, this case report highlights the efficacy of soft X-chrome lenses in ameliorating congenital CVD, particularly red-green impairments. Customized interventions, including thorough comprehension of mechanisms, patient expectation management, and lens care education, are essential. Prioritizing personalized care and ethical patient management underscores the potential of these lenses in enhancing the quality of life for individuals with CVD.
Color vision testing identifies deficiencies impacting safety and professional performance. Our study of 60 patients showed most first learn of their deficiency during mandatory driver's license exams. Many are unaware of their specific type of deficiency, highlighting diagnostic gaps.
Color vision testing has undergone significant facelift with ongoing developments enhancing accuracy, efficiency, and accessibility. The introduction of computer-based color vision tests has allowed for more standardized administration and scoring, reducing subjectivity. Advances in molecular genetics have led to a better understanding of the genetic basis of color vision deficiencies. Genetic testing can now identify specific gene mutations associated with various types of color blindness. Additionally, this chapter looks at the mobile applications and web-based tests that allow individuals to perform color vision assessments remotely, facilitating screening in diverse settings.
Aims
To examine the association between colour vision deficiency (CVD) and other ophthalmic disorders including amblyopia, strabismus and ametropia in a large population study.
Methods
The retrospective, cross-sectional study included 916 388 Israeli army male recruits who had their premilitary medical assessment at the age of 16–18 years from 2000 to 2020, analysing the prevalence of ophthalmic disorders including amblyopia, strabismus and ametropia in army recruits with CVD compared with all other recruits with normal colour vision. Demographic and socioeconomic data were also collected.
Results
The prevalence of amblyopia (1.28% vs 0.71%, p<0.001), strabismus (1.09% vs 0.83%, p<0.001) and ametropia (moderate—less than 6.00 diopters, 35.05% vs 30.50%, p<0.001 and high—higher than 6.00 diopters, 3.18% vs 2.30%, p<0.001) were all higher among 28 001 (3.06%) army recruits with CVD compared with all other individuals with normal colour vision. CVD was more common in individuals with a higher socioeconomic status (high 3.15% vs low 2.93%, p<0.001) and varied according to recruits’ origin. It was most frequent in individuals whose mother was born in the former Soviet Union (4.98%) compared with other European countries (3.89%), North America (3.28%), Asia (2.78%) and Ethiopia (1.63%).
Conclusion
CVD is associated with an increased frequency of amblyopia, strabismus and ametropia, which can all impart vision difficulties besides colour vision impairment alone.
It is 200 years since George Palmer suggested that colour vision depended on three classes of molecule or membrane. The present paper gives an introductory review of what is today known of the opsins, of the genes that encode them, and of the alterations to which they are subject. Several theories of anomalous trichromacy are briefly reviewed.
A broadband red filter placed over one eye will have the effect of improving the ability of certain color vision defectives to name colors correctly. A red-tinted contact lens will have the same effect; such a device is marketed under the name, the X-Chrom lens. In this article, the author examines the basic properties of color vision defects, explains the optical effect of the red filter, and reviews several studies which evaluate the effect of the X-Chrom lens. He concludes that while the lens may allow the wearer to achieve a better score on certain color vision tests, it does not actually correct color vision in the natural environment. Deleterious effects of wearing a red filter are also discussed. It is advised that patients wearing the X-Chrom lens be fully apprised of its limitations and of dangers that may be created by the associated visual distortions.
Citation
DEANE B. JUDD, "Facts of Color-Blindness," J. Opt. Soc. Am. 33, 294-294 (1943)
http://www.opticsinfobase.org/josa/abstract.cfm?URI=josa-33-6-294
The color deficient often seek visual aids to mitigate their color confusions. The most popular aids are red high-pass filters worn monocularly. Any benefit offered by such aids is limited to specific tasks and/or hue regions and may be negated by deleterious side- effects, including reduced luminance and visual acuity, induced visual distortions, altered stereopsis, and impaired depth perception. Different types of filters, taking into account advances in the molecular genetics of color vision and in coating technology, may offer greater advantages. © 2000 John Wiley & Sons, Inc. Col Res Appl, 26, S269–S272, 2001