Acquired Colour Vision Deficiencies Research Articles

Impact of Prolonged Screening and COVID-19 Infection on Acquired Colour Vision Deficiencies Assessed by the Farnsworth–Munsell 100 Hue Test

Over the past decade, global screening time has increased, a trend intensified by the COVID-19 pandemic, leading to the integration of screens into daily life. Studies have documented the adverse effects of prolonged screening on ocular health and binocular vision, such as dry eye syndrome, blurry vision, headaches, myopia, and visual fatigue. However, it remains unclear if prolonged screening affects the development of colour vision defects. Objectives: This study aimed to determine the relationship between (a) prolonged screening and acquired colour vision deficiencies and (b) COVID-19 infection and acquired colour vision deficiencies. Methods: A population of 50 individuals with normal trichromatic vision, aged 20 to 30 years, with an average daily screening time of 516.7 min, was evaluated. Participants were initially screened using the Ishihara 32-plate Test to exclude those with congenital colour vision deficiencies. The Farnsworth–Munsell 100 Hue Test (FM100H) and Square Root Total Error Score (√TES) were used to evaluate acquired colour vision deficiencies under standardized conditions. The dataset underwent dual analysis: (1) detailed statistical scrutiny and (2) comparison of √TES values with historical data from 1982, 1991, 2001, and 2002. Results: The global group had a √TES (Mean ± SD) of 5.40 ± 1.58, the COVID-19 subgroup 5.46 ± 1.62, and the non-COVID-19 subgroup 5.32 ± 1.51. No significant differences were found between the √TES values from this population and those reported in previous studies. Statistical analysis showed no significant correlation between gender and COVID-19 infection with √TES values. Conclusions: Neither screening time nor COVID-19 infection appears to significantly impact the occurrence of permanently acquired colour vision deficiencies in individuals aged 20 to 30 years.

Development and validation of a new colour vision screener: A multi‐centre study

Aims/Purpose: The detection of acquired and congenital colour vision deficiency is of importance in the clinic for the early detection of ocular disease and determination of occupational suitability. Conventional methods of colour vision screening often fail to pass all normals and/or correctly identify those with acquired and congenital colour vision deficiency. The Colour Vision Screener (CVS) test [1] was developed to utilize an improved understanding of colour vision mechanisms to overcome the limitations present in conventional colour screening methods. This study aimed to use a robust multi‐centre methodology to fully validate the CVS test.Methods: Over 400 participants, including 124 normal trichromats, 166 deutans and 62 protans, were recruited from 10 international Colour Assessment and Diagnosis (CAD) testing centres. Each participant completed the CVS and the CAD test with calibrated visual displays. The red/green (RG) and yellow/blue (YB) CVS test sensitivity and specificity were established. The RG statistics were compared to the ‘gold standard’ reference for screening for RG congenital colour vision deficiency—the Ishihara pseudoisochromatic plate test.Results: The CVS test correctly identified ~99.1% of normal trichromats. All subjects with congenital RG loss and acquired loss on top of congenital RG deficiency were identified as having abnormal colour vision by the CVS. The Ishihara test, based upon 0 errors on the first 25 plates of the 38‐plate edition, correctly identifies ~80.6% of normal trichromats and 99.5% of subjects with congenital RG loss.Conclusions: Data collected across 10 international CAD centres demonstrate that the CVS can achieve a high sensitivity without sacrificing specificity. This multi‐centre study demonstrates that the CVS is quick, efficient, and easy to use and allows for the rapid and reliable screening of congenital and acquired colour vision deficiencies in large populations.Reference1. Barbur JL, Rodriguez‐Carmona M, Evans BEW. Colour vision assessment‐3. An efficient, two‐step, colour assessment protocol. Colour Research & Application 2021; 46: 33–45. https://doi.org/10.1002/col.22599

Cone contrast test-HD: sensitivity and specificity in red-green dichromacy and the impact of age.

We report normative cone contrast sensitivity values, right-left eye agreement, and sensitivity and specificity values for the cone contrast test-HD (CCT-HD). We included 100 phakic eyes with color vision normal (CVN) and 20 dichromatic eyes (10 with protanopia and 10 with deuteranopia). The CCT-HD was used to measure L, M, and S-CCT-HD scores, and the right and left eyes were evaluated for agreement using Lin's concordance correlation coefficient (CCC) and Bland-Altman analysis to investigate the sensitivity and specificity of the CCT-HD based on diagnosis with an anomaloscope device. All cone types were in moderate agreement with the CCC (L-cone: 0.92, 95% CI, 0.86-0.95; M-cone: 0.91, 95% CI, 0.84-0.94; S-cone: 0.93, 95% CI, 0.88-0.96), whereas the Bland-Altman plots showed that the majority of cases (L-cone: 94%; M-cone: 92%; S-cone: 92%) fell within the 95% limits of agreement and showed good agreement. The m e a n±s t a n d a r d error L, M, and S-CCT-HD scores for protanopia were 0.6±1.4, 74.7±2.7, and 94.6±2.4, respectively; for deuteranopia, these were 84.0±3.4, 40.8±3.3, and 93.0±5.8, respectively; and for age-matched CVN eyes (m e a n±s t a n d a r d deviation age, 53.1±5.8 years; age range, 45-64years), these were 98.5±3.4, 94.8±3.8, and 92.3±3.4, respectively, with significant differences between the groups except for S-CCT-HD score (Bonferroni corrected α=0.0167, p<0.0167). The sensitivity and specificity of the CCT-HD were 100% for protan and deutan in diagnosing abnormal types in those aged 20 to 64years; however, the specificity decreased to 65% for protan and 55% for deutan in those aged >65 years. The CCT-HD is comparable to the diagnostic performance of the anomaloscope in the 20-64-year-old age group. However, the results should be interpreted cautiously in those ≥65 years, as these patients are more susceptible to acquired color vision deficiencies due to yellowing of the crystalline lens and other factors.

The Association Between Acquired Color Deficiency and PET Imaging of Neurodegeneration in Mild Cognitive Impairment and Alzheimer Disease.

PurposeTo evaluate color vision changes and retinal processing of chromatic and luminance pathways in subjects with Alzheimer disease (AD) and mild cognitive impairment (MCI) compared with a matched control group and whether such changes are associated with impaired brain glucose metabolism and β-amyloid deposition in the brain.MethodsWe evaluated 13 patients with AD (72.4 ± 7.7 years), 23 patients with MCI (72.5 ± 5.5 years), and 18 controls of comparable age (P = 0.44) using Cambridge color test and the heterochromatic flicker ERG (HF-ERG). The Cambridge color test was performed using the trivector protocol to estimate the protan, deutan and tritan color confusion axes. HF-ERG responses were measured at a frequency of 12 Hz, which ERGs reflect chromatic activity, and at 36 Hz, reflecting luminance pathway. A study subsample was performed using neuropsychological assessments and positron emission tomography.ResultsPatients with AD presented higher mean values indicating poorer color discrimination for protan (P = 0.04) and deutan (P = 0.001) axes compared with the controls. Along the tritan axis, both patients with AD and patients with MCI showed decreased color vision (P = 0.001 and P = 0.001) compared with controls. The analyses from the HF-ERG protocol revealed no differences between the groups (P = 0.31 and P = 0.41). Diffuse color vision loss was found in individuals with signs of neurodegeneration (protan P = 0.002, deutan P = 0.003 and tritan P = 0.01), but not in individuals with signs of β-amyloid deposition only (protan P = 0.39, deutan P = 0.48, tritan P = 0.63), regardless of their clinical classification.ConclusionsHere, patients with AD and patients with MCI present acquired color vision deficiency that may be linked with impaired brain metabolism.

Color Vision Pathway Follows the Expansion Repeats in SCA7

Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant neurodegenerative disorder caused by gene ataxin7 mutation with a polymorphic CAG repeat tract that falls in first axon. The gene which encodes ataxin7 normally contains a ten CAG repeat tract starting a codon 30, in affected patients the CAG repeat tract expands from 37 to 250 triplets, decreasing the transcription of an antisense non-coding RNA. Clinically SCA7 is characterized by progressive cerebellar ataxia, slow saccadic eye movements and progressive blindness. SCA7 neurotoxicity can be showed by the cone-rod dystrophy which follows in the generations the CAG repeats expansions in the affected patients. As retinal disease progresses in SCA7, the photoreceptors cells do become involved, and then loss of central visual acuity proceeds to complete blindness. The presence in the long run of the altered cone function, allows SCA7 to be classified as a cone dystrophy type of retinal degeneration [1]. Considering the X-linked inheritance of color vision deficiency, fixed sampling of only males, that compensation’s phenomenon in the heterozygous females [2], which can hid a real acquired color vision deficiency. The acquired color vision deficiency is real in the males where the anomaly has not hidden, and due to this reason we suggest sampling only male patients when color vision has studied both in neurological and metabolic diseases [3].

Evaluation of acquired color vision deficiency in retinal vein occlusion using the Rabin cone contrast test.

To investigate acquired color vision deficiency (CVD) using the Rabin cone contrast test (RCCT) in patients with retinal vein occlusion (RVO). We retrospectively evaluated 39 patients with macular edema due to RVO who were treated with intravitreal injections of anti-VEGF agents and demonstrated improvement of best-corrected visual acuity to 20/20 Snellen VA or better. The acquired CVD was evaluated by the RCCT and standard pseudo-isochromatic plates-part 2 (SPP-2). Mean L, M, and S color contrast test (CCT) scores were significantly lower in RVO eyes than in the fellow eyes (L CCTs, 70.0 ± 13.3 vs. 90.0 ± 8.0, respectively, P < 0.01; M CCTs, 85.0 ± 16.6 vs. 95.0 ± 5.7, respectively, P < 0.01; S CCTs, 80.0 ± 21.5 vs. 95.0 ± 7.1, respectively, P < 0.01). Acquired CVD was diagnosed in 25 eyes of 39 patients by the RCCT and in 15 eyes of 39 patients by SPP-2. The RCCT was performed on two different days in 21 patients. It revealed acquired CVD in 17 eyes on the first day and in 10 eyes on the second day. Acquired CVD was improved in 9 eyes, unchanged in 8 eyes, and worsened in 2 eyes. The RCCT revealed eyes with RVO had acquired CVD. Acquired CVD caused by RVO can be improved further in some cases even after recovery of vision to 20/20. The RCCT may be able to quantitatively diagnose acquired CVD status.

The Change in Color Vision with Normal Aging Evaluated on Standard Pseudoisochromatic Plates Part-3

ABSTRACT Purpose: To evaluate the influence of aging on color vision in a large normal population using Standard Pseudoisochromatic Plates part-3 (SPP-3), which is a pseudoisochromatic plate test used to detect congenital or acquired color vision deficiency (CVD). Materials and methods: We retrospectively reviewed SPP-3 test results of 23,565 normal eyes of 23,565 subjects (women: 12,035; men: 11,530), who were examined between July 1993 and December 2010. The subjects had a mean age of 46.9 ± 18.5 years, ranging from 5 to 89 years, and they were evaluated following categorization into age groups with five-year increments. Subjects whose best-corrected visual acuity (BCVA) was 20/20 or better, with no history of ocular diseases, were included. Subjects with congenital CVD were excluded. Results: We found a negative correlation between age and the total number of correct answers in SPP-3 (Spearman’s correlation coefficient, r = −0.5743; p < .0001). The total number of correct answers was the highest in subjects aged 10–14, 15–19, and 20–24 years (17.2 ± 0.9 [mean ±SD]). The total number of correct answers of these groups had significant differences from those in the 5–9 years age group and those aged >30 years (Dunn’s post-hoc test: p < .0001). Among the 19 detection numerals in SPP-3, we found that the correct answer rates of six numerals decreased with aging, and the colors of the numerals and their backgrounds all located parallel to the tritanopic confusion line. Conclusions: Using SPP-3, we confirmed that aging influenced color vision, even in normal eyes with a good BCVA (20/20 or better). The total number of correct answers of SPP-3 was the highest in subjects aged 10–24 years and had already begun to decline in those in their 30s.

Color vision testing in children

AbstractColor vision is an important part of visual processing and as such, it often needs to be evaluated in the pediatric population. The information on a child's color vision status can often be a very important additional clue in establishing the correct clinical diagnosis. The basic principles of color vision are discussed in this review, as well as congenital and acquired color vision deficiencies. The emphasis is on the evaluation of color vision, especially clinically applicable color vision tests suitable for testing children above the age of 3 years.

Incidence of dyschromatopsy in glaucoma.

As proven in studies dating back to the eighteenth century, color vision changes may occur early in the course of glaucoma. Our aim was to reevaluate the incidence of acquired color vision deficiency in glaucoma patients of the University hospital Zürich by using the Panel D-15 test. Inclusion criteria of the study involved a diagnosis of glaucoma, age equal or greater than 18years with no upper limit and a best-corrected visual acuity (BCVA) smaller than ≤ 0.7 logMAR. All volunteers were tested twice monocularly for color vision with (1) the Ishihara color plate test and (2) the Farnsworth and Lanthony Panel D-15 test by one examiner (L.B.). Using the Moment of Inertia Method of Vingrys and King-Smith (Investig Ophthalmol Vis Sci 29(1):50-63, 1988), we measured the color defect type (blue-yellow, red-green or non-selective). One hundred and fifty-one eyes of 87 glaucoma patients were included in this study. Nine eyes showed a deficient result in the Ishihara test, which proves a congenital red-green weakness. Fifty-one (33.8%) eyes showed color vision anomalies in the desaturated test and 24 (15.9%) eyes in the saturated Panel D-15 test. A total of 25.2% and 8.6% of eyes in the desaturated and saturated test were diffuse dyschromatopsia, respectively. The second most prevalent deficiencies were blue-yellow defects with 4.0% and 4.6% of saturated and desaturated results. Just the covariate visual acuity had a significant influence on the Panel D-15 result, whereas other variables like age, sex or intraocular pressure did not show any impact. This study ascertains that the long-known theory of color vision defects in patients with glaucoma is also relevant in our sample of 151 eyes, providing continuity to claims firstly reported many years ago. Despite our results highlighting more diffuse dyschromatopsia than other similar experiments, we have also proven that the tritanomalous defects occur more frequently than other color defects.

Visual Acuity, Contrast Sensitivity, Colour Vision: Thoughts on Psychophysical Exams in Neuro-ophthalmology

Despite many technical advances, psychophysical testing of perceptual performance continues to play an important role in ophthalmic diagnostics, including neuro-ophthalmology. The present article considers methodological and clinical aspects of examining visual acuity, contrast sensitivity, and colour vision. In contrast to acuity, contrast sensitivity is at present rarely tested, despite often being a more sensitive marker of disease. In general, standardised procedures have the advantage of a high degree of comparability. However, tests that deviate from the standard might be better adapted to detect the characteristic impairments associated with a specific visual disorder, which justifies their application in certain cases. This also applies to colour vision testing. Preliminary evidence suggests that the measurement of colour saturation thresholds might be a more efficient and more sensitive alternative to conventional colour vision tests in cases of acquired colour vision deficiencies.

Congenital and acquired colour vision deficiency among population in North Kordofan State of Sudan

Background: Congenital colour vision deficiency (CVD) is an x-linked chromosome disorders which, predominantly occurring in males. This disorder results from abnormalities in one or all three-cone type's photoreceptors. It is mainly affect long wavelength photopigments (red) and middle wavelength photopigments (green). However, the acquired CVD is due to ocular or general pathology as well as due to prolonged use of some medications, which is mostly affect short wavelength photopigments (blue). Objective: This study aimed to evaluate the prevalence of hereditary and acquired CVDs among Sudanese population in North Kordofan State. Materials and Methods: This is a population-based crossed-sectional study of 1100 subjects, their age ranged from 10 to 80 years, the mean age of subjects was 40.4 ± 16.6 (standard deviation) were selected from three districts and 110 subjects were selected from each set. Investigations included visual acuity using Snellen tumbling E-chart, refraction using retinoscopy, colour vision using Ishihara and City University colour vision tests, external eye using torch and magnifier and evaluation of internal eye and ocular media using direct ophthalmoscope. Results: A total of 1216 subjects were invited to participate in the study and 1100 were examined resulting in a participation rate of 91%. The findings revealed that 61 (5.5%) had CVD, 49 (9.0%) were males and 12 (2.2%) were females. The prevalence of congenital (red-green) CVD was 39 (3.5%) which was high in males 37 (6.8%) than females 2 (0.4%). The prevalence of congenital CVD was found associated with males (P

Historical Development of the Wool and Colour Plate Tests for Screening for Colour Vision Deficiencies in German Speaking Countries

Colour vision is a complex visual function that can be affected by congenital and/or acquired disorders. The frequency of congenital colour vision deficiencies has been investigated in rail and navy staff since the 1870s. Various test methods have been developed. Wool tests, flor contrast tests and colour plate tests have been used. A published colour plate test, based on Stilling's pseudo-isochromatic plates in combination with a flor contrast test, has been a common screening method for colour vision testing in German-speaking countries. This test is intended to detect congenital and acquired colour vision deficiencies in a simple and safe manner. More modern options, such as Internet and tablet PC have technical limitations, but will increasingly be used for screening for colour vision deficiencies.

Defects of colour vision: A review of congenital and acquired colour vision deficiencies

Colour vision deficiencies (CVDs) can be categorised as being congenital or acquired. Some CVDs are already present at birth, as inherited conditions that are the result of changes at the photo-pigment level and are non-pathological, incurable and do not change over time. Examples are red-green defects which are inherited as an X-linked recessive trait. Acquired CVD develops secondary to ocular and systemic conditions or as a side effect of certain medications or sometimes toxic effects of chemicals, and trauma and ageing can also be important in some CVDs.

Evaluation of Contrast Sensitivity, Chromatic Vision, and Reading Ability in Patients with Primary Open Angle Glaucoma.

Purpose. To compare contrast sensitivity, acquired color vision deficiency, and reading ability in patients with glaucoma at different stages of the disease and to establish correlations between visual field parameters and visual function scores. Methods. This prospective cross-sectional study included 121 glaucoma patients. Subjects with a diagnosis of chronic open angle glaucoma were recruited and classified according to Hodapp-Parrish-Anderson criteria. Patients with severe visual field defects were excluded because they were older, which could bias the interpretation of visual function tests. Contrast sensitivity was measured using the Pelli-Robson Chart and the CSV1000E test. Chromatic vision was evaluated using the Farnsworth-panel D15 and the L'Anthony D15 tests of Vision Color Recorder software. Reading ability was measured using Radner-Vissum test. Results. Contrast sensitivity (with photopic and mesopic luminance with glare) differed significantly between patients with early and moderate visual field defects (p < 0.05). Reading ability scores and results of the chromatic vision tests did not differ significantly between the two groups. Significant and moderate Spearman correlations between visual field indexes and contrast sensitivity tests were detected. Conclusions. Contrast sensitivity was significantly worse in patients with moderate glaucoma compared to those with early-stage glaucoma. Evaluation of visual function in clinical practice provides important information to address a glaucoma patient's vision complaints.

Ability of Bottle Cap Color to Facilitate Accurate Patient–Physician Communication Regarding Medication Identity in Patients with Glaucoma

To determine the accuracy of patient-physician communication regarding topical ophthalmic medication use based on bottle cap color, particularly among individuals who may have acquired color vision deficiency from glaucoma. Cross-sectional, clinical study. Patients aged ≥18 years with primary open-angle, primary angle-closure, pseudoexfoliation, or pigment dispersion glaucoma, bilateral visual acuity of ≥20/400, and no concurrent conditions that may affect color vision. A total of 100 patients provided color descriptions of 11 distinct medication bottle caps. Color descriptors were then presented to 3 physicians. Physicians matched each color descriptor to the medication they thought the descriptor was describing. Frequency of patient-physician agreement, occurring when all 3 physicians accurately matched the color descriptor to the correct medication. Multivariate regression models evaluated whether patient-physician agreement decreased with degree of better-eye visual field (VF) damage, color descriptor heterogeneity, or color vision deficiency, as determined by the Hardy-Rand-Rittler (HRR) score and Lanthony D15 color confusion index (D15 CCI). Subjects had a mean age of 69 (±11) years, with VF mean deviation of-4.7 (±6.0) and-10.9 (±8.4) decibels (dB) in the better- and worse-seeing eyes, respectively. Patients produced 102 unique color descriptors to describe the colors of the 11 bottle caps. Among individual patients, the mean number of medications demonstrating agreement was 6.1/11 (55.5%). Agreement was less than 15% for 4 medications (prednisolone acetate [generic], betaxolol HCl [Betoptic; Alcon Laboratories Inc., Fort Worth, TX], brinzolamide/brimonidine [Simbrinza; Alcon Laboratories Inc.], and latanoprost [Xalatan; Pfizer, Inc., New York, NY]). Lower HRR scores and higher D15 CCI (both indicating worse color vision) were associated with greater VF damage (P < 0.001). Extent of color vision deficiency and color descriptor heterogeneity significantly predicted agreement in multivariate models (odds of agreement= 0.90 per 1 point decrement in HRR score, P < 0.001; odds of agreement= 0.30 for medications exhibiting high heterogeneity [≥11 descriptors], P= 0.007). Physician understanding of patient medication use based solely on bottle cap color is frequently incorrect, particularly in patients with glaucoma who may have color vision deficiency. Errors based oncommunication using bottle cap color alone may be common and could lead to confusion and harm.

Colour Vision in Stargardt Disease

Purpose: To investigate the type and severity of acquired colour vision deficiencies (CVDs) in molecularly proven Stargardt disease (STD) and to establish whether a relationship exists between best-corrected visual acuity (BCVA) and full-field electroretinography (ffERG), and the degree of CVD. Methods: A retrospective, cross-sectional study of 73 patients with a molecularly proven diagnosis of STD, who underwent extensive colour vision evaluation, using pseudo-isochromatic and arrangement tests. Thirteen patients underwent Nagel anomaloscopy. Results: Normal colour vision was found in almost 20% of patients. Red/green (R/G) CVDs increased as BCVA declined. About 45% of all R/G CVDs were of the deutan type, although protan type CVDs became progressively apparent when moving from the high to the low BCVA group. An additional blue/yellow CVD was noted in about 25% of patients. In 10/13 patients, a pseudoprotanomaly was noted on anomaloscopy. Severe CVDs leading to scotopization were noted in patients with low BCVA and/or long-standing disease. No statistically significant differences in ERG results were found between groups with or without a CVD. Conclusions: The degree and type of colour vision deficiency in STD patients correlate better with BCVA than with ffERG results. The presence of specific CVDs may help to establish a diagnosis of STD. A battery of colour vision tests is required to properly evaluate CVDs in STD.

Evaluation of acquired color vision deficiency in glaucoma using the Rabin cone contrast test.

To evaluate acquired color vision deficiency in glaucoma by using the Rabin cone contrast test (RCCT). Twenty-seven eyes of 27 patients with glaucoma (glaucoma group) and 27 eyes of 27 normal subjects (control group) were included in this study. Long (L), medium (M), and short (S) CCT scores (L CCTs, M CCTs, and S CCTs, respectively) were measured using the RCCT in both groups. Visual field examinations were performed with Humphrey automated perimetry using the Swedish interactive thresholding algorithm 30-2, and the mean deviation (MD) was evaluated. The macular ganglion cell/inner plexiform layer (GCIPL) thickness was measured using high-definition optical coherence tomography in the glaucoma group. The mean M CCTs and S CCTs in the glaucoma group were significantly lower (P<0.05 for both comparisons) than in the control group (M CCTs, 80.7±16.8 vs. 91.9±8.22; S CCTs, 83.9±19.5 vs. 97.4±3.77, respectively); the L CCTs did not differ significantly (P=0.065) from those of the controls (91.8±12.8 vs. 97.4±3.50, respectively). The M CCTs and S CCTs were correlated significantly with those of MD (M CCTs, r=0.47; S CCTs, r=0.44; P<0.05 for both comparisons) and GCIPL thickness (M CCTs, r=0.70; P<0.0001; S CCTs, r=0.57; P<0.01). The chromatic discrimination thresholds measured by RCCT in the glaucoma group were significantly different from those measured in the control group and were correlated with the MD and GCIPL thickness. The RCCT may be useful for evaluating acquired color vision deficiency in glaucoma and may help advance current understanding of the pathophysiology of glaucomatous damage.

Color vision deficiency in a middle-aged population: the Shahroud Eye Study

The aim of this study was to determine the prevalence of color vision defects in the middle-age population of Shahroud, Iran. We selected 6,311 people from the 40- to 64-year-old population through random cluster sampling. Color vision testing was performed with the Farnsworth D-15. Cases with similar and symmetric results in both eyes were classified as hereditary, and those with asymmetric results were considered acquired. Cases that did not conform to standard patterns were classified as unknown category. Of 5,190 respondents (response rate 82.2 %), 5,102 participants underwent the color vision test. Of these, 14.7 % (95 % confidence interval 13.7-15.6) had some type of color vision deficiency. Of the 2,157 male participants, 6.2 % were hereditary and 10.2 % were acquired and of the 2,945 female participants, 3.1 % were hereditary and 10 % were acquired. Hereditary color deficiencies were mostly of the deutan form (63.8 %), and acquired deficiencies were mostly tritan (66.1 %). The prevalence of hereditary and acquired color vision deficiency, as well as different types of red-green and blue-yellow color vision defects significantly increased with age (p < 0.001). In conclusion, the pattern of color vision defects among the middle-aged population of Shahroud was significantly different from that seen in the younger population. This could be due to changes associated with age, gender, medical and ocular conditions, and differences in race and environment. Thus, results of previous examinations and the overall health status should be considered before making any judgment about the status of color vision in middle-aged people.

Examination of colour vision deficiency in different types retinitis pigmentosa

AbstractPurpose Investigation of the colour vision deficiency in different typees of retinitis pigmentosa (RP): autosomal dominant, autosomal recessive, X‐linked recessive, and isolated cases.Methods Colour vision investigation was conducted on 42 patients (18 women, 24 men) with RP using the Farnsworth 28 HUE‐test, anomaloscope –IF‐2 Tomay, flicker threshold test, standard pseudoisochromatic table and Tritan Lantonie album. The age of the patients varied from 5 to 68 years (mean 39 ± 17, SD),Results In 73,3 % of patients with RP we established acquired colour vision deficiency (dyschromatopsy) . Among the patients with aquired colour vision deficiency we found out using the above‐mentioned tests that 67,8% were with tritanopy, 19,3% were with manifested deuteranomaly and 12,9 % were with protanomaly. The type of dyschromatopsy does not show any relation to the age and visual aquity of patients. When no foveal lesion was apparent in patients with visual acuity better than 20/40, patients with autosomal dominant disease showed superior performance on color vision testing when compared to autosomal recessive, X‐linked recessive, and isolated cases. The Farnsworth 28 HUE test was more sensitive in detecting poor color vision performance than the anomaloscope –IF‐2 Tomay.Conclusion We established a great percentile of patients with RP suffer from colour vision deficiency. Our study reveals that colour vision investigation has an important role in PR diagnosis.

Saturation‐specific pattern of acquired colour vision deficiency in two clinical populations revealed by the method of triads

AbstractSubjective colour spaces were reconstructed for persons occupationally exposed to mercury (Hg) and patients with diabetes mellitus type 2, two groups at risk for acquired colour‐vision deficiency, and compared with healthy normal trichromats. Judgments of colour dissimilarity were collected with the method of triads, applied to a composite assortment of colour samples. These were drawn from two widely used colour arrangement tests—10 hues from the Farnsworth D‐15 test and five from the Lanthony Desaturated D‐15d test, ensuring that the assortment sampled two levels of lightness and saturation. The data were analyzed with maximum‐likelihood multidimensional scaling (MDS) and within a novel individual‐differences MDS model to estimate subject‐specific parameters. The MDS solutions for the two clinical groups showed a compression along a blue‐yellow axis, limited however to desaturated hues. This result was confirmed by the individual‐differences model. In addition, the clinical groups were found to place significantly higher weights on the lightness differences between stimuli, conceivably to compensate for their reduced chromatic discrimination. The specific form of colour‐space distortion in the clinical groups indicated an increase in their thresholds for blue‐yellow signals, providing insights into the nature of impairment mechanisms. The results have implications for stimuli and diagnostic procedures for testing individual differences in color vision, and for analyzing the responses. This approach is sensitive to distinctive patterns of subtle colour‐vision impairment underestimated by the conventional D‐15d test. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 125–135, 2014