Ishihara Color Vision Research Articles

Colour Vision Defects: Awareness, Prevalence And Effects Among Secondary School Students In Imo State, Nigeria

Abstract Background: Colour vision defect (CVD) is a public health issue with approximately one in ten males exhibiting some form of colour deficiency. Colour is used extensively in education so CVD has a dramatic impact on the learning, educational and social potentials of children. Racial differences have been reported with higher values noted amongst people of European ancestry. Objective: This study aims to assess CVDs, their magnitude and impact on the daily activities of secondary school students in Imo State, Nigeria. Materials and Methods: This was a multistage, cross-sectional, descriptive study which assessed the prevalence and effect of congenital CVD on secondary school students in Imo state using a questionnaire modified and adapted for this purpose. Colour vision was tested uniocularly for each student under bright illumination using the 38-plate Ishihara colour vision chart and Lanthony D-15 colour panel. The test was administered on a black background between the hours of 10 a.m. and 2 p.m. Results: Eight hundred and twenty-eight secondary school students were studied with a mean age of 15 ± 1.89 years. There were 468 males (57.0%) and 360 females (43%) with a male-to-female ratio of 1.3:1. There was a 3% prevalence of CVD. More males were significantly affected than females. Deutan defect was more common and none of the students had tritan defect. Conclusion: There is a low level of awareness of congenital CVD. This disorder resulted in various degrees of difficulty with colour-related school and daily living tasks. Advocacy to government and schools is needed to create awareness of CVDs and offer early counselling to those affected.

Reversible visual recovery in Optic Neuritis patient with No Light Perception VA

Abstract
 Introduction : Optic neuritis is characterized by an inflammation and demyelination of the optic nerve and is traditionally treated with corticosteroids. The findings of the ONTT, reported in more than 50 publications during the past 20 years, have numerous implications
 Case Illustration : A 48-year-old woman presented to the ophthalmology outpatient clinic with a 12-day history of blurred vision. The best-corrected visual acuities and Ishihara colour vision was unilaterally reduced with a non light perception on left eye. There were also relative afferent pupillary defect with slow respons of pupillary reflect. Slit-lamp examination was otherwise normal. Funduscopy was Papillary edema on left eye, with all quadrant blurry edge. Optic neuritis (ON) was presumed as she had suffered with this previously. She was hospitalized and undergone (optic neuritis treatment trial) ONTT . Thereafter, a trial of pulsed methylprednisolone was commenced, resulting in near complete resolution of the Visual acuity that become 6/40 UCVA from NLP.
 Discussion : The original ONTT, along with three follow-up studies at five-year intervals, generated more than three dozen papers in scientific journals. Collectively they show what happens to an individual over the course of 15 years following about of optic neuritis.
 Conclusion : Prior to the ONTT well-established guidelines for treating optic neuritis did not exist, this case were demonstrates the importance of keep starting ONTT with a point valuable to patient with NLP.

LONG-TERM FOLLOW-UP ON A RARE CASE OF PERIOPERATIVE POSTERIOR ISCHEMIC OPTIC NEUROPATHY: FINDING HOPE IN THE DARKNESS

Abstract
 Introduction : Perioperative posterior ischemic optic neuropathy (PION) following maxillectomy is a rare and devastating condition that leads to permanent vision loss in most reported cases. This case report offers a different perspective through long-term follow-up, providing valuable insights into the prognosis and potential treatments for PION.
 Case Illustration : Following a left maxillectomy for ameloblastoma, a 28-year-old female experienced sudden vision loss in her left eye. The visual acuity was 5/60, and an altitudinal inferior visual field defect with a superior extension was present. Ishihara's color vision examination revealed 15/38. The patient was diagnosed with perioperative PION and treated with neurotropic and folic acid. After 16 months, optic atrophy was observed. However, there are complete recovery in visual acuity to 5/5 and Ishihara score to 38/38, along with a significant improvement in the visual field defect.
 Discussion : The current management of perioperative PION is focused on prevention, because once vision loss occurs, it is usually severe and irreversible. In our case, the patient exhibited a favorable outcome after a long follow-up period, suggesting that there is still potential for improvement in PION patients. The finding is consistent with previous study, which reported that a small percentage of patients may still experience improved vision during follow-up. The role of neurotropics in improving patient outcomes is further supported by in vitro studies that demonstrate early neurotropic treatment significantly prevents loss of retinal ganglion cells in PION.
 Conclusion : Visual improvement is still possible in perioperative PION and early neurotropic administration may be considered in therapy

Prevalence and genotypic frequency of color vision defects among primary schoolchildren in Adama Town, Eastern Ethiopia.

Color vision deficiency is a common X-linked genetic disorder affecting the day-to-day lives of individuals, in which school-aged children's academic performance can be negatively affected. The aim of this study was to evaluate the prevalence and genotypic frequency of congenital color vision defects (CVD), among primary schoolchildren in Adama, Ethiopia. A school-based cross-sectional study design was used. Students were purposively selected based on their ethnicity but were randomly selected from their sections, resulting in a final sample size estimated at 846 schoolchildren who had received informed consent from their families. Data was gathered using the Ishihara color vision test, 38-plate edition. The result of the study revealed that the total prevalence of CVD was much higher (5.6%) among the male children than that of the females, which was only about 1.79%. The prevalence rates of CVD among the targeted ethnic groups were found to be the highest among Amhara (7.45%) > Oromo (5.00%) > Gurage (2.13%) children, respectively, in descending order. 62.76% of the study subjects were homozygous dominant (AA), followed by those with a heterozygous genotype (Aa) (32.51%), and the remaining 4.73% had recessive (aa) genes.

Digoxin‐induced retinal toxicity after acute kidney injury in a patient with dilated cardiomyopathy: A case report

Aims/Purpose: We would like to report a case of digoxin‐induced retinal toxicity.Methods: Observational case report. Clinical follow‐up was performed using optical coherence tomography and electroretinography.Results: A 50‐year‐old female patient was referred to our clinic with symptoms of blurred vision and a whitening of the central visual field. She had no prior ophthalmic history but had underlying diseases including hypertension, hyperlipidaemia, dilated cardiomyopathy, systemic lupus erythematosus and chronic kidney disease. She had been admitted to the department of nephrology due to acute renal impairment, presenting with flank pain and oliguria. At the initial examination, her best‐corrected visual acuity was 0.5 in the right eye and 0.4 in the left eye. The Ishihara colour vision test revealed 3/17 and 1/17 in the right and left eye, respectively. Optical coherence tomography showed blurring and thickening of the ellipsoid zone in both eyes. Electroretinography demonstrated decreased cone cell function. She had been taking digoxin 0.125 mg for dilated cardiomyopathy for the past 2 years. Following the onset of acute renal impairment, her serum digoxin level was found to be 2.95 ng/mL, more than twice the normal range [0.6–1.2]. Suspecting digoxin intoxication, we consulted with her cardiologist and decided to discontinue digoxin. 3 weeks after discontinuing the medication, she reported improvement in the whitening of central visual field. Her best‐corrected visual acuity improved to 0.7 in the right eye and 0.6 in the left eye, and the Ishihara colour vision test showed 16/17 in both eyes. OCT demonstrated normalization of the ellipsoid zone thickness, and ERG showed ongoing recovery of cone cell function.Conclusions: Digoxin toxicity is known to result in visual disturbances—including decreased visual acuity, blurry vision and central scotoma with altered colour perception—caused by direct dysfunction of photoreceptors. Symptoms are gradually recovered within days to months after discontinuation of the medication. When facing visual problems in a patient with comorbidities, it is important to elicit a complete history, with all drug and detailed complaints, and to include a drug adverse effect. If a drug intoxication was suspected, medical consultations should be obtained.

Are red/green colour vision deficient individuals at altered risk of myopia?

Aims/Purpose: To investigate the association between red/green colour vision deficiency (CVD) and myopia in Irish and Australian participants.Methods: Data from the Ireland Eye Study (IES; age 12–13 years), Raine Study Gen2 cohort (Australia; age 18–22 years) and Kidskin Study (Australia; age 25–30 years) were used. Colour vision was assessed with the Hardy‐Rand‐Ritler (IES) or Ishihara colour vision test (Raine, Kidskin). Right eye spherical equivalent refractive error (SER; myopia defined as SER ≤ −0.50 dioptres [D]) was measured with cycloplegic autorefraction and right eye axial length (AXL) with interferometry. Participants who were female, or with incomplete colour vision or refraction data, tritanomaly, monochromacy, previous surgery or condition‐altering refraction were excluded. Linear and logistic regression were used for analysing binary and continuous outcomes, respectively, with an interaction between study country and CVD.Results: After exclusions (n = 56), there were 2488 participants of whom 1286 (51.7%) were male (IES: n = 503, Raine: n = 676 and Kidskin: n = 107). The prevalence of CVD across the IES, Raine and Kidskin studies, respectively, was 5.8% (16 deutan, 9 protan, 5 unclassified), 5.5% (18 deutan, 3 protan, 16 unclassified) and 6.5% (6 deutan, 1 unclassified). After adjusting for age, any red/green CVD was not associated with myopia risk (odds ratio [OR] = 1.31, 95% confidence interval [95%CI]: 0.86–2.32, p = 0.36), SER or AXL. However, when analysed by CVD type, deutan CVD was associated with higher odds of myopia (OR = 2.31, 95% CI 1.19 to 4.44, p = 0.01) and a more myopic SER (difference = −0.61D, 95% CI: −1.09 to −0.12, p = 0.02; AXL: difference = 0.09 mm, 95%CI: −0.19 to 0.37, p = 0.51), compared to non‐CVD participants, while other CVD types were not associated with myopia (protan: OR = 0.94, 95% CI 0.20–4.41, p = 0.94; unclassified: OR = 0.36, 95% CI 0.08–1.56, p = 0.17), SER or AXL.Conclusions: In contrast to previous findings in Chinese school students, participants with a deutan CVD in this study had a higher risk of myopia.

Impact of color vision deficiency on the quality of life in a sample of Indian population: Application of the CVD-QoL tool

Purpose: To investigate the quality of life (QoL) in a sample of color vision deficit (CVD) patients in India and how color vision deficiency affects them psychologically, economically, and in productivity related to their work and occupation. Methods: A descriptive and case–control study design using a questionnaire was conducted on N = 120 participants, of whom 60 were patients of CVD (52 male and eight female) who visited two eye facilities in Hyderabad between 2020 and 2021 and 60 were age-matched normal color vision participants who served as controls. We validated English–Telugu adapted version of CVD-QoL, developed by Barry et al. in 2017 (CB-QoL). The CVD-QoL consists of 27 Likert-scale items with factors (lifestyle, emotions, and work). Color vision was assessed using the Ishihara and Cambridge Mollen color vision tests. A six-point Likert scale was used, with lower scores indicating poor QoL (from 1 = severe issue to 6 = no problem). Results: The CVD-QoL questionnaire’s reliability and internal consistency were measured, including Cronbach’s a (a =0.70–0.90). There was no significance between the group in age (t = −1.2, P = 0.67) whereas the Ishihara colour vision test, scores showed a significant difference (t = 4.50, P < 0.001). The QoL scores showed a significant difference towards lifestyle, emotions and work (P = 0.001). The CVD group had a poorer QoL score than the normal color vision group odds ratio [OR] =0.31, 95% confidence interval [CI], (P = 0.002, CI = 0.14–0.65, Z = 3.0) . In this analysis, a low CI indicated that the OR was more precise. Conclusion: Color vision deficiency affects Indians’ QoL, according to this study. The mean scores of lifestyle, emotions, and work were lower than the UK sample.Since CVD is underreported and possibly affects developing countries more, advocacy for a new health care plan on CVD is essential. Increasing public understanding and awareness could also help diagnosing the CVD population.

Stargardt-like Clinical Characteristics and Disease Course Associated with Variants in the WDR19 Gene.

Variants in WDR19 (IFT144) have been implicated as another possible cause of Stargardt disease. The purpose of this study was to compare longitudinal multimodal imaging of a WDR19-Stargardt patient, harboring p.(Ser485Ile) and a novel c.(3183+1_3184-1)_(3261+1_3262-1)del variant, with 43 ABCA4-Stargardt patients. Age at onset, visual acuity, Ishihara color vision, color fundus, fundus autofluorescence (FAF), spectral-domain optical coherence tomography (OCT) images, microperimetry and electroretinography (ERG) were evaluated. First symptom of WDR19 patient was nyctalopia at the age of 5 years. After the age of 18 years, OCT showed hyper-reflectivity at the level of the external limiting membrane/outer nuclear layer. There was abnormal cone and rod photoreceptor function on ERG. Widespread fundus flecks appeared, followed by perifoveal photoreceptor atrophy. Fovea and peripapillary retina remained preserved until the latest exam at 25 years of age. ABCA4 patients had median age of onset at 16 (range 5-60) years and mostly displayed typical Stargardt triad. A total of 19% had foveal sparing. In comparison to ABCA4 patients, the WDR19 patient had a relatively large foveal preservation and severe rod photoreceptor impairment; however, it was still within the ABCA4 disease spectrum. Addition of WDR19 in the group of genes producing phenocopies of Stargardt disease underlines the importance of genetic testing and may help to understand its pathogenesis.

AWARENESS AND KNOWLEDGE OF COLOR VISION DEFICIENCY AMONG HEALTH CARE STUDENTS WITH INTERVENTION

Objective: To assess the level of awareness and knowledge of Color Vision Deficiency and to determine problems related to color vision among health care students.&#x0D; Methods: This study was done on 278 Health care students in the age group of 18 to 25 y. Structured Pre and Post assessment questionnaires were administrated to all consenting students to determine the prevalence of Color Vision Deficiency and a video is shown to assess the level of awareness and knowledge of Color Vision defects. Color Vision was tested by using Ishihara Color Vision Chart. This study was conducted between November 2021 to January 2022. Ethical clearance for the study was obtained from Saveetha College of Allied Health Sciences.&#x0D; Results: A total of 278 subjects participated in this study, 277(99.6%) subjects have a normal level of Color Vision. Around 66.5% of subjects were aware of color vision deficiency in pre-assessment and 100% of subjects were aware in post-assessment, around 99.6% of subjects found no difficulty in choosing colors of clothes, cosmetics, 100% of subjects had no color difficulty in previous and daily work/study activities and among them, one subject (0.35%) could not appreciate color considered as total Color blindness according to the chart used.&#x0D; Conclusion: It is concluded from this study that a large group of students attains a normal level of Color Vision. Most of them (66.5%) are aware of Color Vision deficiency in pre-assessment, after providing them with adequate awareness and knowledge increases to 100% in post-assessment.

Outcomes of transcorneal electrical stimulation therapy in the early stages of retinitis pigmentosa.

To investigate the effect of transcorneal electrical stimulation (TES) therapy in patients with retinitis pigmentosa (RP). We performed TES therapy in 21 patients with RP in 12 sessions with 1-week intervals. The following parameters obtained before and after the TES therapy were compared statistically; the best corrected visual acuity (BCVA, logMAR), Ishihara color vision level, multifocal electroretinography (mf-ERG) response, automated visual field (VF) outcome, and the 25-item low vision quality-of-life (LVQOL) questionnaire points. The mean age of patients (6 females; 15 males) was 31.67 ± 9.80 years (20-50 years). While increases in BCVA level, color vision level, mf-ERG response in p1 amplitude of ring 1, and LVQOL questionnaire points were statistically significant, changes in VF test and other mf-ERG responses were not. Twenty of the patients (95.24%) stated that they were satisfied with the TES therapy. No considerable side effect was observed in any patient due to the therapy. The TES therapy may be an effective and safe treatment modality in slowing the RP progression, especially in the early stages of the disease. Longer-term follow-ups in larger patient populations are warranted.

Comparing The Validity Of Electronic Color Vision Test With Conventional Ishihara Pseudoisochromatic Plate Test

Many ocular diseases can affect color vision of a patient which will ultimately reduce many daily based activities. Measuring color vision of a patient can help deciding any management plan for that patient. Objectives:To compare the validity of electronic color vision test with conventional pseudoisochromaticishihara plates and to find out easiest and appropriate method of color vision testing.Methods: This was a cross-sectional study involving the use of structured proforma and questionnaire to evaluate the validity of electronic color vision test and conventional ishihara plate test. A sample size of 80 individuals with normal and mild degree of refractive error was examined and results were recorded in self-designed proforma. Results: Eighty individuals were enlisted; 35 were males (43.8%) and 45 (56.3) were female; age ranged from 14 to 56 (average 34.2+ 12.2) years. By conventional ishihara testing 68 patients gave 100% results (n = 68; 85%) and 12 gave 75% (n = 12; 15%) results. In electronic color vision test 69 individuals gave 100% ( n = 69; 86.3%) results and 11 gave 75% (n = 11; 13.7%) results. 45% peoples are satisfied with their electronic color vision test, 20% satisfied with both methods however 35% are satisfied with conventional method. Prevalence of color vision defect is higher in males as compared to females. Conclusions: This study found that the sensitivity and specificity of electronic color vision test and conventional ishihara test is nearly similar (p&lt; 0.05). Electronic Ishihara color vision test is also a way of self assesment and also has the advantage of reducing the cost through decreasing resources and the time to analyze the results.

Color-blindness simulation for red-green and blue-yellow ambiguity

Color blindness has important effects on people’s daily activities, since most activities require a discernment between colors. It is very important for engineers and designers to understand how colorblind people perceive colors. Therefore, many methods have been proposed to simulate color perception of people affected by Dichromacy and anomalous Trichromacy. However, the simulation results rarely have been evaluated with the reports of concerned individuals. In first study, we tried to simulate the color perception of people with different types (red and green) and different degrees of color blindness. Different degrees of red-green deficiency is simulated on the 24-plates brand of the Ishihara color vision test kit. Then simulated plates were tested on people with normal color vision. The results show that the simulation performance is better in the case of high degrees of red-green deficiency. There is also a clear difference between the assessment of female and male volunteers. In another study, the perception of the color of people with blue-yellow blindness is also considered. The proposed blue-yellow blind simulation is compared with the result of another research project. The results show that the color perception of individuals with different degrees of blue-yellow blindness can be reconstructed with a reasonable accuracy.

Vergleich zweier Screening-Verfahren zur Farbsinnprüfung: Ishihara-Tafeln vs. digitales Replikat

Comparison of two screening procedures for testing colour perception: Ishihara plates vs. digital replication Purpose: The study was designed to prove that the digitalized colour vision test integrated into the Optovist II is equivalent to the traditional Ishihara colour charts. Methods: Colour vision was tested with a sample size of 220 subjects (36 colour-deficient) and three different test methods. A new version of the Ishihara tablets was used under standard lighting conditions and at a distance of about 75 cm. The colour vision test (digitalized Ishihara plates) of a calibrated Optovist II (Vistec AG, Olching) and an HMC anomaloscope (Oculus Optikgeräte GmbH, Wetzlar) were also used. The first 17 plates of the Ishihara test were assessed in both the Ishihara colour vision test and the Optovist II, because the plates contain 18–24 lines that are not suitable for testing in the vision-testing device. Results: The test subject was classified as colour-deficient after two false readings of the pseudoisochromatic plates. The Ishihara plates provided the correct result in 200 subjects compared to the gold standard anomaloscope. In contrast, the Optovist II rated correctly in a total of 202 subjects. In the case of the Ishihara plates, 17 persons with normal colour vision were identified as having a colour deficiency, and three colour-deficient persons were classified as colour-competent. The Optovist II classified 16 colourcompetent persons as colour-deficient, and two colour-deficient persons as colour-competent. In addition, it was possible to test for equivalence using the McNemar test and to verify this. Conclusion: The two test methods should be considered equivalent. Both methods – Ishihara plates and their digital replica in the Optovist II – should be used exclusively as a screening method. A test with the anomaloscope should be performed for the final diagnosis. Keywords: Ishihara colour vision test – pseudoisochromatic panels – color vision – anomaloscope – digital colour vision test

EEG signal analysis during Ishihara’s test in subjects with normal vision and color vision deficiency

Color Vision Deficiency (CVD) is one of the most common types of vision deficiency. People with CVD have difficulty seeing color spectra depending on what types of retina photoreceptors are impaired. In this paper, the Ishihara test with 38 plates was used to examine the Electroencephalogram (EEG) of ten subjects with CVD plus ten healthy individuals. The recording was performed according to the 10–20 international system. The C-based software was programmed so that subjects could select the number or path in each test plate in the software options while recording EEG. Frequency features in different frequency bands were extracted from the EEG signals of the two groups during the Ishihara test. Statistically significant differences (P < 0.05) between features were assessed by independent samples t-test with False Discovery Rate (FDR) correction. Also, the K-nearest neighbor classifier (KNN) was used to classify the two groups. The results revealed that the most significant difference between the two groups in the Ishihara test images occurred for the electrodes located in the right temporoparietal areas (P4 and T6) of the brain in the Delta, Theta, Beta1, and Beta2 frequency bands. The KNN classifier, using the signals that reported the greatest statistical difference between the two groups, showed that the two groups were distinguishable with 85.2% accuracy. In this way, images from the Ishihara test that would provide the most accurate classification were identified. In conclusion, this research provided new insights into EEG signals of subjects with CVD and healthy subjects based on the Ishihara color vision test.

Optic neuritis with normal visual acuity – A case report

Background: Optic neuritis is an acquired disorder of the optic nerve due to inflammation or demyelination. Diagnosis of optic neuritis was based mainly on clinical signs and symptoms, ancillary tests only help confirm the diagnosis or follow treatment progress. However, in cases with high visual acuity and with mild or without optic disc edema, the disease can be easily underdiagnosed. Case report: We report a case of optic neuritis with normal visual acuity. The patient complained of blurring vision and mild pain in her right eye upon gazing; however, her right eye best corrected visual acuity was 20/20. Ishihara color vision test was 20/24 on her right eye and 24/24 on her left eye. Relative afferent pupillary defect was detected, fundus examination revealed mild optic disc edema, and visual field test showed enlarged physiological blind spot on her right eye. The patient received careful follow-up with no corticosteroids treatment. After 3 months, all the signs and symptoms resolved completely. Conclusion: This case demonstrated that optic neuritis can be easily underdiagnosed; relative afferent pupillary defect check, visual field, magnetic resonance imaging and color vision test should be performed in every suspected cases. Strict follow-up check, instead of corticosteroids may be of priority when patient visual acuity is still good.

Commentary: Significance of early screening for color vision in children.

One of the most common inherited vision disorders is congenital color vision deficiency (CVD). Its prevalence in men can be as high as 8% and 0.5% in women.[1] Men are predominately affected by the X-linked inheritance pattern, while women become carriers of the abnormal gene.[2] There are also different causes for acquired color vision defects, such as ocular or neurological disease, some metabolic disorders, drug toxicity and exposure to certain solvents.[3] Congenital CVD results from genetic mutations that affect the expression of the full complement of normal cone photoreceptors. They’re divided into three categories based on their intensity (anomalous trichromacy, dichromacy, and monochromacy). CVD places the sufferer at a distinct disadvantage when performing certain visual tasks—in particular those tasks in which a colored target is embedded in a variegated background of a different color. CVD affects many areas of life, and its adverse impact is experienced at all stages, i.e., from childhood to adolescence and adulthood.[45] Population is one of the biggest problems in India and the reason for so many compromises starting from lack of resources at every level. Healthcare is just one example. When providing even simple vision assessment in school children becomes a big task few tests like color vision examination is rarely being performed. Population diagnosis is usually late at the time of medical examination at the time of higher education or specific job. They are rarely diagnosed early in life. Late diagnosis leads to rejection for a particular job most of the time which has a psychological impact on individuals. In India where an education system doesn’t give a student to choose multiple streams, it turns out, several professional choices can be negatively impacted by a color blindness diagnosis. CVD is a hidden disability because, though present from birth, its role comes to play only when children begin to attend regular schools to learn some tasks.[6] From here onwards process of considerable difficulties in learning starts. Children with CVD are frequently marked as lethargic students, which could mentally affect them, or could evoke negative responses from instructors and guardian. This can lead to not only problems in learning but also in playing and in their social bonding. Various studies have been carried out all over the world to see the prevalence of CVD among school children.[789] Xie JZ, et al.[10] suggested that successful CVD testing can be done starting at age four. Cole stressed that school children should know if they have CVD so they can be helped more quickly to find adaptive strategies and be able to take it into account when planning their career.[11] Largest study on CVD in children is conducted to see the burden of this disability in India.[12] Authors have used Dalton’s psuedoisochromatic plates for color vision screening. It is based on Ishihara color vision chart principle. The Dalton screener consists of 6 sets with 4 plates in each that includes one demo plate and three screening plates. Those, who failed to read three or more plates in two or more random sets of the Dalton’s pseudoisochromatic plate were considered to have CVD after confirming with Ishihara’s PIP color vision testing (38 plate edition). The result shows CVD among boys was found to be 2.76%. Children from urban region (3.17%) were more likely to be color vision deficient than children from rural region (1.79%). These results are similar to the other parts of the country and few other countries from Asia. Screening of CVD is relatively easy does not require any formal training and can be performed by any assigned staff. Various plate tests are available, such as Ishihara, Tokyo, HRR plate test, which are highly sensitive and specific to detect CVD. Because of rapidly evolving technologies with more and more use of color coded tasks in each sector including education sector and specific job requiring color differentiation, the efforts should be made at a fundamental level in screening of color vision defects during comprehensive school eye health programs. Since CVD is congenital and there is no permanent cure for it. However, advice at an early age could help to find adaptive strategies, which enable them to avoid disappointments in the choice of their future career. Parental education, awareness, genetic counseling strategies in the regions with high CVD incidence could help a lot in minimizing the occurrence of the disorder among their offspring.

Photoacoustic imaging for non-invasive examination of the healthy temporal artery - systematic evaluation of visual function in healthy subjects.

Photoacoustic (PA) imaging has the potential to become a non-invasive diagnostic tool for giant cell arteritis, as shown in pilot experiments on seven patients undergoing surgery. Here, we present a detailed evaluation of the safety regarding visual function and patient tolerability in healthy subjects, and define the spectral signature in the healthy temporal artery. Photoacoustic scanning of the temporal artery was performed in 12 healthy subjects using 59 wavelengths (from 680nm to 970nm). Visual function was tested before and after the examination. The subjects' experience of the examination was rated on a 0-100 VAS scale. Two- and three-dimensional PA images were generated from the spectra obtained from the artery. Photoacoustic imaging did not affect the best corrected visual acuity, colour vision (tested with Sahlgren's Saturation Test or the Ishihara colour vision test) or the visual field. The level of discomfort was low, and only little heat and light sensation were reported.The spectral signature of the artery wall could be clearly differentiated from those of the subcutaneous tissue and skin. Spectral unmixing provided visualization of the chromophore distribution and overall architecture of the artery. Photoacoustic imaging of the temporal artery is well tolerated and can be performed without any risk to visual function, including the function of the retina and the optic nerve. The spectral signature of the temporal artery is specific, which is promising for future method development.

Tele-Neuro-Ophthalmology During the Age of COVID-19.

Tele-Neuro-Ophthalmology During the Age of COVID-19.

THE SIGNIFICANCE OF TRAINING AND EDUCATION IN ACCURATE EVALUATION OF NATURAL TOOTH COLOR

Color is undoubtedly one of the parameters with the highest weight when it comes to assessing the quality of restoration by the patient, especially in the anterior zone of the oral cavity. By precisely matching the restoration color with the remaining teeth, the possibility of inconvenience such as a correction or re-making of the same restoration is minimized. Since determining tooth color in everyday practice is done visually by using specially made color selection shade guides, unawareness of the correct method and the conditions under which it should be administered may increase the failure of the therapy. The aim of our research was to determine whether education and training in determining tooth color influence the choice of precise and correct shade. The study included a total of (N = 90)dental medicine students who were first tested with the Ishihara color vision test and Farnsworth-Munsell 100 HueColor Vision test to exclude the possibility of an error due to the presence of a color vision anomaly of the eye. We have formed two groups with an equal number of respondents, work and control group. Both groups were tested twice with a special color coding program ToothGuideTrainer WEB-final exam, which uses VITA Linearguide 3D-MASTER® shade guide. During the testing, the working group went through education, in the form of lectures, exercises and training tests for determining the color. The control group did not attend the training. The results from both tests were electronically counted. Mean value and standard deviation were determined. Differences between the work and control group were analyzed with t-test. The workgroup showed statistically significant higher points after education and training than the control group. The points earned before training did not differ significantly between the two groups. The education and training for shade matching in dentistry significantly affect the success of selecting the perfect color for future restoration. It is necessary to include more intensive training in determining color within the program of dental medicine studies. The conditions in which the tooth color matching is performed should be strictly controlled.

Prevalence and causes of low vision among urban and rural school children

Background: The objective of this study is to determine the prevalence and the causes of low vision among school going children in and around Rohtak district of Haryana, India. Such information is important in planning for prevention of low vision and blindness strategies.Methods: 2028 school children studying in class 1-5 were screened in the school premises. Visual acuity was assessed with Snellen’s chart and colour vision was tested with ishihara colour vision book. Those with vision &lt;6/18 in both eyes were assessed at our tertiary care hospital to determine the cause of low vision.Results: A total of 2028 children were enrolled in our study. 58 children were found to have uncorrected visual acuity less than 6/18 (functional low vision) in the better eye. Uncorrected refractive error was the most common cause of functional low vision (51.72%) among the 2028 children enrolled in our study followed by amblyopia (32.7%), cataract (5.1%), corneal opacity (5.1%), retinal dystrophy (5.1%), nystagmus (1.7%) and optic nerve glioma (1.7%).Conclusions: The overall prevalence of low vision in our study is higher as compared to previous studies. A comparison between academic performances of children with low vision and rest of the children showed that children with low vision tend to perform poor academically. The prevalence of amblyopia was significantly higher in children from the rural background which emphasizes the importance of rural school screening programmes. It was found that amblyopia was significantly higher in females as compared to males in both rural and urban areas.