PURPOSE: The objective of this study was to determine the visual function of colour-deficient subjects when wearing special red tint contact lenses.
MATERIALS AND METHODS: A total of 17 subjects with congenital colour vision deficiency (14 deutans and 3 protans), voluntarily participated in this study. The average age for the subjects was 23.00 ± 4.06 years old. Visual functions tested were visual acuity (LogMAR), contrast sensitivity (FACT Chart) and stereopsis (TNO and Howard Dolman tests). Two types of special red tint lenses were used in this study; Type I (light red) and Type II (dark red).
RESULTS: The protans and deutans showed no significant changes in visual acuity and contrast sensitivity when wearing either type of contact lens. Stereopsis testing using the Horward-Dolman test gave no significant changes but significant differences were seen using the TNO test. Stereopsis using the TNO test was significantly poorer with the red tinted contact lenses compared to without for both protons and deutans. Testing binocularly with Ishihara plates showed that 88% (n=15) of patients passed the test with Type I and Type II contact lenses. When D15 test was done, 3 patients (17.6%) were 'normal' when using the Type I contact lenses and 2 patients (11.8%) were 'normal' when using the Type II contact lenses. However, with FM100Hue test, most patients showed deutan responses. Total error scores (TES) were found to be higher with Type I and Type II contact lenses compared to without.
CONCLUSIONS: The Type I and II special tinted contact lens used in this study did not cause a reduction of visual acuity and contrast sensitivity for the colour defects. Stereopsis was also not reduced with the Type I and Type II contact lenses for the colour defects except when tested with the TNO test. Colour vision defects became difficult to detect using the Ishihara plates but FM100Hue test did not show any improvement with the Type I and Type II contact lenses.
Matched MeSH terms: Color Vision Defects/rehabilitation*
1829 school-boys of Singapore comprised of 849 Chinese, 469 Malays and 511 Indians were investigated for the incidence of red-green colour-blindness with Ishihara's plates. The incidence of red-green colour-blindness was found to be 3.8%, 4.5% and 4.5%, respectively in Chinese, Malay and Indian boys. The incidence among the different dialect groups was variable with the highest incidence of red-green colour-blindness among Mandarin speaking group (14.3%), followed by Hainanese speaking (6.7%) and other dialect groups of Chinese (2.8% to 4.5%). The incidence of red-green colour-blindness was higher in the older boys compared with the younger boys when all the three ethnic groups are combined.
Matched MeSH terms: Color Vision Defects/epidemiology*
Background: Congenital colour vision deficiency (CCVD) is an untreatable disorder which has lifelong consequences. Increasing use of colours in schools has raised concern for pupils with CCVD. This case-control study was conducted to compare behavioural and emotional issues among age, gender and class-matched pupils with CCVD and normal colour vision (NCV). Methods: A total of 1732 pupils from 10 primary schools in the Federal Territory of Kuala Lumpur were screened, of which 46 pupils (45 males and 1 female) had CCVD. Mothers of male pupils with CCVD (n=44) and NCV (n=44) who gave consent were recruited to complete a self-administered parent report form, Child Behaviour Checklist for Ages 4-18 (CBCL/ 4-18) used to access behavioural and emotional problems. The CBCL/ 4-18 has three broad groupings: Internalising, Externalising and Total Behaviour Problems. Internalising Problems combines the Withdrawn, Somatic Complaints and Anxiety/ Depression sub constructs, while Externalising Problems combines the Delinquent and Aggressive Behaviour sub constructs. Results: Results from CBCL/ 4-18 showed that all pupils from both groups had scores within the normal range for all constructs. However, results from the statistical analysis for comparison, Mann-Whitney U test, showed that pupils with CCVD scored significantly higher for Externalising Problems (U=697.50, p=0.02) and Total Behaviour Problems (U=647.00, p= 0.01). Significantly higher scores were observed in Withdrawn (U=714.00, p=0.02), Thought Problems (U=438.50, p<0.001) and Aggressive Behaviour (U=738.00, p=0.04). Odds ratios, 95% CI, showed significant relative risk for high Total Behaviour Problem (OR:2.39 ,CI:1.0-5.7), Externalising Problems (OR:2.32, CI:1.0-5.5), Withdrawn (OR:2.67, CI:1.1-6.5), Thought Problems (OR:9.64, CI:3.6-26.1) and Aggressive Behaviour (OR:10.26, CI:3.4-31.0) scores among pupils with CCVD. Conclusion: Higher scores among CCVD pupils indicates that they present more behavioural and emotional problems compared to NCV pupils. Therefore, school vision screenings in Malaysia should also include colour vision to assist in the early clinical management of CCVD children.
Matched MeSH terms: Color Vision Defects/congenital*; Color Vision Defects/psychology*
PURPOSE: A survey on new Malaysian drivers was conducted in Malaysia between year 2006-2009. The objective of this study was to look at the effectiveness of the present computerized visual screening tool and to compare it with the conventional testing method.
METHODS: A total of 3717 drivers aged 19±6 years, who had passed in the computerized visual screening, participated in this study.
RESULTS: 250 subjects achieved less than 0.3 LogMAR with their best eye and 83 subjects failed the Ishihara Test after retested using the conventional tool.
CONCLUSION: These finding showed the computerized visual screening test failed to filter some subjects according to the standards set.
KEYWORDS: Visual acuity; colour vision; driving; vision
The majority of patients with dysthyroid eye disease have an acquired colour vision defect. However, no psychophysical investigation of selective damage to colour or flicker pathways has been carried out. In order to clarify the nature of the visual pathology, we have used a psychophysical technique (spectral sensitivity) to selectively stimulate the chromatic and achromatic mechanisms. Spectral spots of size 1 degree presented at a rate of 1 Hz on a bright 1000 td white background are detected by the chromatic mechanism but a rate of 25 Hz reveals the achromatic mechanism. Fifteen patients (28 eyes) between the ages of 50-70 years were tested. The study showed that all patients had reduced spectral sensitivity, either 1 Hz, 25 Hz or both. The patients with reduced 1 Hz or 25 Hz spectral sensitivity only had a shorter systemic and ocular duration of the condition, had no proptosis, normal intraocular pressures in primary gaze, slightly higher intraocular pressures on upgaze, normal visual field plots and FM 100-Hue error scores higher than the normal age-matched values. The patients with reduced both 1 Hz and 25 Hz spectral sensitivities had a longer systemic and ocular duration of the condition, had proptosis, normal intraocular pressures in primary position, higher intraocular pressures on upgaze and higher FM 100-Hue error scores than the age-matched normals and those in Groups 1 and 2. A total of 50% of patients in Group 3 had defective visual field plots. These data suggest that there is a damage of the large achromatic fibres and small chromatic fibres in dysthyroid eye disease. The mechanism of the damage could be one of ischaemic or mechanical or both.
Matched MeSH terms: Color Vision Defects/diagnosis*
A cross-sectional survey of commercial vehicle drivers who were renewing their own licences was conducted at the Selangor Road Transport Department office in Padang Jawa between 1 February 2002 and 28 February 2002, using questionnaire and medical examination. The objective was to determine the prevalence of myopia, colour vision deficiency and visual field defect among the commercial vehicle drivers. The respondents that reported visual defect at the time of interview was compared with those detected by the author through medical examination. Out of the 223 respondents, 21 (9.4%) reported to have myopia by the questionnaire survey. Through the visual examination there were 63 (28.3%) with myopia (visual acuity worse than 6/12),six (2.6%) had a visual field defect and 14 (6.3%) had red-green colour deficiency. The visual defect detected during the study among the commercial vehicle drivers, which were missed at the time of the routine medical examination were significant. The process of the statutory medical examination should be reviewed.
A study was undertaken to determine the effect of polyethylene and polystyrene used in the manufacture of plastic items on colour perception. Colour vision was assessed using the Ishihara plates, panel 015 test and the Farnsworth Munsell 100-Hue test. Two factories were chosen at random. One factory (referred here as factory A) used virgin resin in pellet form (polyethylene) in the manufacturing of plastic containers to store consumer edible oil. The other factory (referred as factory B) used polystyrene to make plastic bags. A total of 39 healthy employees from factory A (mean age 26.4 :t 8.2 years) and 40 healthy employees from factory B (mean age 26.8 :t 9.6 years) were recruited in this study. A control group of 27 normal healthy subjects (mean age 27.4 :t 4.3 years) who were employees of UKM with no occupational involvement with petroleum derivatives were also recruited in this study and they performed the same colour vision tests. All subjects passed the Ishihara plates test showing that none of the subjects (employees of factory A and B, and control subjects) had a congenital red-green defect. All control subjects passed all of the colour vision tests whilst some employees of factories A and B failed the 015 and FM100 Hue tests. For employees from factory A results from the 015 test showed that 7 (17.9%) had a tritan (blue-yellow) type of defect and 1 (2.6%) had a complex type of defect. The FM 100 Hue results of factory A employees showed that 51.3% (n=20) had a complex type of defect. Total error scores (TES) calculated from the FM 100 Hue test revealed that employees from factory A had a statistically significant higher mean TES of 65.13:!: 48.31 compared to that of control subjects with a mean TES of 31.26:!: 14.93. For employees in factory B, 10 employees (25.0%) had a tritan (blue-yellow) type of defect and 2 (5.0%) had a complex type of defect. Results of the FM 100 Hue test showed that 4 employees (1.0%) had a tritan type of defect whereas 22 (55.0%) had a complex type of defect. Mean total error scores (TES) calculated from the FM 100 Hue test revealed that employees from factory B had a statistically significant higher mean TES of 71.54 :t 54.63 compared with that of control subjects with a mean TES of 31.26 :t. 14.93
The above results show that employees of the plastic factories studies are associated with a higher risk of acquiring colour vision defects as compared to normal subjects who are not engaged in the plastic manufacturing industry. This may have an implication towards the future retinal health of employees in petrod1emical-based industries.
This study was conducted for 3 main purposes: 1) to determine if there was blue colour deficiency amongst diabetes mellitus (IDDM and NIDDM) patients without retinopathy, 2) to determine if the Dl5 test could be used to detect any colour vision defects amongst diabetics without retinopathy (all previous workers have used FM 100-Hue), and 3) to assess the performance of diabetics without retinopathy in detecting correct colour changes with the urine strip test. Thirty eight non-insulin dependent diabetes mellitus (NIDDM) and 30 insulin-dependent diabetes mellitus (IDDM) patients without retinopathy participated in this study. A control group of 23 normal subjects were also included in the study. Dl5 colour vision test was performed under daylight conditions. Colour dependent urine glucose test (Glukotest) was also performed on all subjects. The study showed that 47.1% of diabetics (47.4% NIDDM and 46.7% IDDM patients) without retinopathy had a blue colour deficiency. Amongst the diabetics with a blue colour deficiency, 25% of diabetics (22% of NIDDM and 28.6% of IDDM patients) failed to accurately match the strip colour with the comparison chart on the bottle.
Kajian ini dilakukan untuk 3 tujuan: I) untuk menentukan samada terdapat gangguan penglihatan warna biru dalam pesakit diabetes mellitus (IDDM dan NIDDM) tanpa retinopati, 2) untuk menentukan samada ujian penglihatan warna Dl5 boleh digunakan untuk mengesan defek penglihatan warna dalam pesakit diabetes tanpa retinopati (kesemua kajian terdahulu menggunakan ujian FM 100-Hue). dan 3) untuk menilaikan prestasi pesakit diabetik tanpa retinopati dalam mengesan perubahan warna yang betul dengan menggunakan ujian strip urin. Tiga puluh lapan pesakit dengan non-insulin dependent diabetes (NIDDM) dan 30 pesakit dengan insulin dependent diabetes (IDDM) tanpa retinopati menyertai kajian ini. Kumpulan kawalan mengandungi 23 orang subjek yang normal juga terlibat di dalam kajian ini. Ujian penglihatan warna Dl5 dilakukan di bawah cahaya daylight. Ujian glukos urin berasaskan warna (Glukotest) dilakukan ke atas semua subjek. Kajian menunjukkan 47.1% pesakit diabetes (47.4% pesakit NIDDM dan 46.7% pesakit IDDM) tanpa retinopati mengalami defisiensi warna biru. Dalam kumpulan diabetik dengan defisiensi warna biru, 25% pesakit diabetes (22.2% adalah pesakit NIDDM dan 28.6% adalah pesakit IDDM) gagal untuk memadankan dengan tepat warna strip dengan carta perbandingan warna di atas botol.
Introduction: Good visual acuity (VA) coupled with the ability to discriminate colours and having a sufficiently wide field of view are factors needed for safe driving. This study aimed to determine the types of colour vision deficiency (CVD) among failed candidates for driving license and to identify the accuracy of the Road transport Department (RTD) screening tests in detecting those who have poor VA and CVD in Sabah.
Methods: A cross-sectional study on the patient’s records of all failed candidates for the driving license that were referred for further assessment by an optometrist. This study was conducted at eight hospitals in Sabah from March to June 2019. Basic demographic data, distance VA, Ishihara test and Farnsworth-Munsell D15 test were collected. Descriptive statistics were used to summarise the results. All subjects referred with best-corrected visual acuity (BCVA) 0.3 LogMAR were included.
Results: A total of 73 subjects (79% males and 21% females), age range from 16 to 61 years (mean 29±13 years) were recruited. Bajau, Dusun, Bugis and Kadazan were the major ethnic among the subjects. Mean VA on attendance was 0.1 ± 0.19 LogMAR, while BCVA was 0.0 ± 0.07 LogMAR. Thirty-six subjects (49%) were found to have CVD. The prevalence of CVD was more in males than females (45% vs 4%). Most of the CVD were deutans (25%) followed by protans (22%), no findings of tritan CVD In this study, 37 subjects (51%) passed the Ishihara test. These were the false-positive error of the RTD screening tests.
Conclusions: Hereditary red-green perceptive disorder was the commonest CVD in Sabah. The severity of CVD was not been evaluated in this study because it is best evaluated using Hardy Rand and Rittler (HRR) test. The false-positive results might be because of technical error or unfamiliar of using computerized colour vision test, especially among elderly candidates. Visual field screening might be considered in the future to ensure safe driving.
Keywords:visual acuity (VA), colour vision deficiency (CVD), driving license
NMRR Research ID: NMRR-19-1785-48811
PURPOSE: The objective of this study was to determine the prevalence of poor visual acuity, colour blindness and visual field defect of new Malaysian drivers.
METHODS: A total of 3717 new drivers (50.2% males and 49.8% females) age 19±6 years, voluntarily participated in this study. Standard optometric apparatus such as LogMAR Charts, Ishihara plates and HandHeld Bernell Perimeter were used and standard procedures were applied.
RESULTS: The visual examination showed 6.7% (n=250) of subjects achieved less than 0.3 LogMAR with better eye whilst 2.2% (n=83) had failed the Ishihara Test (2.1% males and 0.1% females). Most of the affected drivers were deutranopia. Only 2094 subjects had their visual field using a mobile Handheld Bernell Perimeter. 1.72% (n=36) subjects have less than 120 degrees of peripheral field of vision.
CONCLUSIONS: The visual status among new Malaysian drivers needs to be taken seriously to ensure safe driving. Other factors such as colour vision and visual field screening have to be considered seriously when evaluating the visual performance of a driver. Good visual performance is indispensible for safe driving.
A survey of colour vision deficiency among 1427 medical students and healthcare personnel in Seremban revealed a prevalence of 3.2% with a marked male predominance (males 6.7%, females 0.4%). In view of the potential difficulties faced by such personnel in clinical works, early detection of this deficiency allowed appropriate counselling.
Objective Epilepsy is a debilitating disease. Visual function changes have been reported and may be attributed to the epileptic changes or as a result of medication side effect. Sodium valproate and carbamazepine are both first line anti-epileptic medications used in Malaysian health care. Sodium valproate inhibits glutamate and γ-aminobutyric acid (GABA) transaminase while carbamazepine acts on the sodium channel - both are an important part of the retina. This study aimed to compare the visual functions of epilepsy patients on carbamazepine or sodium valproate monotherapy. Design A cross-sectional study was conducted at a tertiary hospital between June 2016 and November 2018. Methods Patients with idiopathic epilepsy that fulfill the inclusion and exclusion criteria were recruited from the neurology clinic. They were divided into two groups and underwent complete eye examinations. Visual functions such as color vision testing, contrast sensitivity, visual field and retinal nerve fiber layer measurement were subsequently performed. Statistical analysis was done using Statistical Package for the Social Science, version 24 (SPSS Inc, Chicago, IL, USA). Results A total of 100 patients (sodium valproate: 50 patients; carbamazepine: 50 patients) were recruited for the study. There were no statistically significant changes in anatomical or visual function between the sodium valproate and carbamazepine group. However, patients from both groups displayed color vision defect in the blue and green axes. Changes in color vision could indicate early retina toxicity secondary to the medication. Although there were no visual field changes, patients recorded a slight reduction of mean deviation. Changes of mean deviation could be attributed to the side effect of medication or the disease process. Conclusions Epileptic patients taking sodium valproate or carbamazepine did not demonstrate statistically significant change in visual function.