Ishihara Test Research Articles

The Prevalence of Congenital Color Vision Abnormality Among Patients Attending a Tertiary Eye Care Center in Southern India.

Background and objective Color vision abnormality is a condition where the faculty to identify one or more primary colors is either defective (anomalous) or absent (anopia). Occupations like armed forces, merchant navy, navigation, and police and fire services require normal color vision. There is a scarcity of data in the literature regarding the prevalence of congenital color vision abnormality in patients in South India. In light of this, the present study aimed to find the prevalence of congenital color vision abnormality in patients attending the Outpatient Department (OPD) at a tertiary eye care center in South India. Materials and methods This was a descriptive cross-sectional study conducted at a tertiary eye care center in South India from December 2014 to December 2016. Patients with a best-corrected visual acuity of 20/20, normal direct and consensual pupillary light reflex, normal anterior segment, and undilated fundus examination were included. Color vision was assessed using Ishihara pseudoisochromatic plates, American Optical Hardy-Rand-Rittler (AO HRR), and then the Farnsworth Munsell D15 arrangement test. All the results were tabulated and statistically analyzed. Statistical significance was calculated using the ANOVA test. Results A total of 371 patients were screened for color vision abnormality; 184 (49.59%) patients were males and 187 (50.40%)were females. Out of 371 patients in the study, 363(98.10%) had normal color vision while eight patients (2.16%) had color vision abnormality. Of the eight patients with color vision abnormalities, six (75%) had abnormal color vision on all three tests and two(25%) had an abnormality on only two tests (Ishihara and AO HRR). Out of 184 males in the study, eight patients (4.34%) had abnormal color vision while none of the 187 females had color vision abnormality; this difference was statistically significant (p=0.03). Conclusions Early diagnosis and providing education and awareness of this condition are necessary as part of guiding young people with regard to their career options and we recommend that all children should undergo color vision screening before entering high school.

Green Light-Based Analgesia – Novel Nonpharmacological Approach to Fibromyalgia Pain: A Pilot Study

BACKGROUND: There continues to be significant reliance on pharmacological modalities for the management of chronic pain, with a particular focus on opioid analgesics as a singular option for pain management. Fibromyalgia is a prototypical central pain disorder, which is often used as a model to study chronic pain disorders. It has an estimated prevalence of approximately 1.1% to 5.4% in the general population. The widespread use of opioids in patients with fibromyalgia has been well demonstrated in several health claims database studies, with rates of use ranging from 11.3% to 69%. Minimizing opioid exposures reduces misuse risk, but requires adequate opioid-sparing multimodal analgesic strategies, particularly nonopioid analgesic adjuncts, to ensure effective treatment of pain, particularly high-impact pain. We chose fibromyalgia as our study population. Given that it is a disordered sensory processing condition, it may be particularly amenable to the beneficial effects of green-light therapy. OBJECTIVES: Most studies have evaluated exposure to light-emitting diode lights as a mode of green-light delivery; our study used green-light filtering eyeglasses, which would allow the wearer to move about with minimal interference. STUDY DESIGN: We conducted a randomized controlled trial to test the feasibility of green-light filtering eyeglasses in the treatment of chronic pain. SETTING: This study was conducted at Duke University Health System. METHODS: We recruited and randomized adult patients with a known diagnosis of fibromyalgia patients and excluded patients who were unable to wear eyeglasses for at least 4 hours per day or were colorblind according to the Ishihara Colorblindness Test. Patients were assigned to 1 of 3 arms: clear eyeglasses (control), green eyeglasses, or blue eyeglasses. We initially recruited 45 patients and randomly assigned 15 patients per group. RESULTS: To evaluate clinical significance, we determined the rate of >= 10% decline in oral morphine equivalents and found that 33%, 11%, and 8% of the green, blue, and clear eyeglass groups, respectively, achieved this clinically meaningful outcome. LIMITATIONS: This study was powered to detect feasibility of the intervention, rather than conclusive analgesic effects. CONCLUSIONS: Our study demonstrated the feasibility of this treatment approach and study design and supports a future study to determine the efficacy of green light-based analgesia on opioid use, pain, and anxiety. While the reduction of opioid use was not of statistical significance, we believe it to be of clinical significance as there was no increase of patient-reported pain. This warrants further investigation in a large-scale trial of the use of green-light filtration of ambient light to mitigate opioid use and possible mediation of psychological impacts of pain with the use of green-lensed eyeglasses. KEY WORDS: Chronic pain, fibromyalgia, pain, pain management, green light, green-light filtering eyeglasses, green-light analgesia, chronic pain management

Design and Development of APP based on Android Vision Testing and Protection

With the rise of mobile platforms, more and more applications are being developed. with the rise of mobile platforms, more and more traditional PC software has been transplanted to mobile platforms, such as iPad, iPhone, Android and other intelligent terminal devices, among these platforms, Android occupies the largest market share, so the development of software to satisfy the daily use of Android users has become a big hit nowadays. In this design, the popular Android platform is used as the development technology to realize an APP software for vision test and protection. This software will bring convenience to the majority of network users to protect their eyesight, and optimize the vision and color blindness test method, saving people's time to go to the hospital for examination, providing a more convenient and efficient test method for the majority of users, and also providing timely prevention of myopia. Through this software, it is more convenient for people to test their eyesight and color blindness and prevent myopia. In this thesis, we will step by step introduce the vision test and protection APP based on Android. This thesis will step by step introduce the background and significance of the development of vision test and protection APP based on Android platform, then introduce the development, design, function and implementation process of this system in detail, and finally summarize this thesis.

Aging variations in Ishihara test plates

AbstractThe Ishihara test plates are designed to offer a rapid and usable instrument to diagnose color deficiency. The original test, as well as other pseudo‐isochromatic plates (PIP), is composed of physical charts produced following proprietary and standard printing procedures. In this work, we aim to measure and assess the color shifts that the aging of the plates may introduce. This work aims to raise the scientific and medical community's awareness of the risks that may occur in using an aged or damaged test, which may still appear in good condition but has been subjected to deterioration over time.

A novel smartphone App to support the clinical practice of pediatric ophthalmology and strabismus: the validation of visual acuity tests.

The novel TreC Oculistica smartphone App was a useful tool for facilitating the clinical practice of pediatric ophthalmology and strabismus during the COVID-19 pandemic. In the follow-up of strabismus patients and patients with suspected inherited retinal diseases, the 9Gaze, eyeTilt, and Color Blind test applications were deemed to be intuitive and easy to use by families and were considered reliable by clinicians. In a home setting, visual acuity tested by means of Snellen Charts was moderately congruent with the in-office examination. On the contrary, agreement was poor in younger children tested with the LEA Symbols pdf. • Teleophthalmology enables clinicians to evaluate patients' ocular diseases remotely and various tools are helpful for screening, follow-ups and treatment. • Smartphones can currently be used to obtain ocular images and vision measurements of patients' eyes and this information can be shared with the ophthalmologist for further evaluations and medical management (mhealth). • Smartphone Apps can be successfully used in a hybrid teleophthalmology service concerning first visits and follow-ups. • Apps and printable materials are easy, intuitive to use for patients and also reliable for clinicians.

The Color Vision Disorder in Diabetic Patients

Introduction: The visible spectrum (about 400 to 700 nm) with a mosaic of three classes of photoreceptors compose the human visual system. They are sensitive to different wavelength ranges with overlapping. The receivers have high sensitivities at short wavelengths (~440 nm), medium (~535 nm), or longer (~565 nm), which are S, M, and L cones, respectively. The study aimed to determine blue color vision defects in diabetes mellitus.
 Methods: A cross-sectional study was done at an ophthalmology clinic on 200 eyes (right and left) of patients with DM for a period of 5 one years (2021). Ishihara plates were used initially for screening. The D-15 test was performed for the evaluation of color vision.
 Results: The mean age of the sample was 45.66±15.65 years. The most frequent disorder visualized was tritanomaly in 63%, followed by trichromate in 27%, and the least disorder was deuteranomaly in 2%. In addition, mixed disorder is seen in 8% of cases. In relation to laterality, right eye tritanomaly was found in 34%, while the left eye was recorded in 29%. The right eye trichromate was observed in 12%, whereas the left eye was reported in 15%. The left eye deuteranomaly was reported more than the right (1.5% vs. 0.5%).
 Conclusion: Color vision evaluation with good screening color vision test can be detected even before clinically visible diabetic retinopathy. Early detection was helpful in the prevention of vascular changes in the retina. All diabetic patients should be given proper awareness and health education regarding color vision deficiency. Timely assessment of color vision may detect tritanomaly earlier in diabetics.

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.

MALT Lymphoma Presenting as Symptomatic Optic Neuritis: A Case Report (P14-13.001)

<h3>Objective:</h3> To report a case of MALT lymphoma presenting as optic neuritis and highlight its inherent diagnostic challenges. <h3>Background:</h3> Optic neuritis (ON) is the inflammation of the optic nerve associated with multiple sclerosis,. ON with atypical clinical features require thorough evaluation. Primary ocular adnexal lymphomas are the most common orbital tumors, and IgG4-related ocular disease also presents with optic neuropathy and consists of morphologically similar immune infiltrates. Their diagnoses are challenging as corticosteroids can incur non-diagnostic biopsies, complicating further workup. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> 51-year-old healthy African American woman presented with one month of progressive left monocular blurry vision, color desaturation and_pain. Exam showed left visual acuity of 20/60, afferent pupillary defect, and 0/13 Ishihara plates identified in left eye. Remainder of exam was intact. MRI demonstrated left optic nerve sheath enhancement and enlargement. Another enhancing lesion was identified in the right inferior orbit. Despite visual impairment, corticosteroids were deferred prioritizing diagnostic tests. Workup was negative for autoimmunity, systemic neoplasm, and infection. CSF showed a bland profile without malignant cells. Serum and CSF IL2 receptor levels returned normal. Oligoclonal bands and IgG were elevated in serum and CSF; IgG4 levels were high at 156, raising concern for IgG4-related ocular disease. Right intra-orbital mass biopsy demonstrated atypical CD20+ lymphoid infiltrates with rare germinal centers, but &lt;10% plasma cells expressed IgG4. Further molecular analysis was positive for monoclonal IgH gene rearrangement, diagnosing mucosa-associated lymphoid tissue (MALT) lymphoma in the right orbit and probable left optic nerve involvement. She was initiated on bendamustine and rituximab with stabilization of her ocular symptoms. <h3>Conclusions:</h3> Atypical presentations of ON warrant thorough workup. IgG4-related ocular disease and ocular adnexal MALT lymphoma share similarities that require histologic and molecular analysis to differentiate. Early identification of MALT lymphoma is crucial to initiate proper therapies, maintain disease control, and preserve visual acuity. <b>Disclosure:</b> Dr. Jia has nothing to disclose. Ms. Wyckoff has nothing to disclose. Dr. Cohen has nothing to disclose. Dr. Bryar has nothing to disclose. Dr. Lukas has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Merck and Company, Inc.. Dr. Lukas has received personal compensation in the range of $0-$499 for serving on a Speakers Bureau for Merck and Company, Inc.. Dr. Lukas has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Novocure. Dr. Lukas has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for EBSCO. Dr. Lukas has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Medlink Neurology. Dr. Lukas has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier. The institution of Dr. Lukas has received research support from BMS. The institution of Dr. Lukas has received research support from BrainUp. The institution of Dr. Lukas has received research support from National Cancer Institute. The institution of Dr. Lukas has received research support from National Cancer Institute. The institution of Dr. Lukas has received research support from Ziopharm. Dr. Dixit has nothing to disclose.

A novel instrument to determine hue discrimination.

We report and verify a novel hue discrimination instrument. We also investigate its efficiency to determine hue discrimination in persons with normal color vision. Experimental and clinical investigation. The instrument setup comprises an optical unit and examination unit. The optical unit is composed of the same 2 spectrometers and their controllers, which enables the independent emission of different spectral lights. Two independent bundle fibers connect the optical unit and the examination unit. Two different wavelength lights are illuminated on the bipartite upper and lower circular objectives with a visual angle of 2 degrees in the examination unit. The examinee recognizes the difference in the spectral lights between the bipartite targets. Persons with normal color vision are examined and the findings are confirmed using the Ishihara Test for Colour Deficiency. The instrument could generate spectral light from 450 to 650 nm within 2-nm accuracy. The spectral light showed a different light intensity according to the spectral centroid, ranging from 450 to 650nm, but the difference could be adjusted and was negligible in terms of determination of hue discrimination using the power meter. Three width slits, 0.2mm, 0.5mm, and 1.0mm, to homogenize the light path were investigated. The half-width wavelength was accurate on each spectral centroid; however, the 0.5mm slit was suitable to generate an efficient light path. The hue discrimination differed among the study participants. In general, at short and long wavelength lights, the hue discrimination range was large: about 15nm at 450nm and about 10nm at 650nm. Between 470 and 620 nm, the hue discrimination showed good sensitivity and specificity between 8 and 2nm depending on the targeting wavelength lights. Intraindividual variation was small, ranging from 3 to 1nm, thus indicating good repeatability. The time to examine the hue discrimination was about 20min. This newly invented instrument using two independent spectrometer units enabled the determination of hue discrimination. The instrument's sensitivity and specificity including its repeatability were confirmed and indicated that the instrument could be a clinically applicable method.

Exploring the Effects of LED-Based Visible Light Communication on Reading and Color Perception in Indoor Environments: An Experimental Study.

Visible light communications (VLC) is a technology that enables the transmission of digital information with a light source. VLC is nowadays seen as a promising technology for indoor applications, helping WiFi to handle the spectrum crunch. Possible indoor applications range from Internet connection at home/office to multimedia content delivery in a museum. Despite the vast interest of researchers in both theoretical analysis and experimentation on VLC technology, no studies have been carried out on the human perceptions of objects illuminated by VLC-based lamps. It is important to define if a VLC lamp decreases the reading capability or modifies the color perception in order to make VLC a technology appropriate for everyday life use. This paper describes the results of psychophysical tests on humans to define if VLC lamps modify the perception of colors or the reading speed. The results of the reading speed test showed a 0.97 correlation coefficient between tests with and without VLC modulated light, leading us to conclude that there is no difference in the reading speed capability with and without VLC-modulated light. The results of the color perception test showed a Fisher exact test p-value of 0.2351, showing that the perception of color is not influenced by the presence of the VLC modulated light.

Screening for mild anomalous trichromacy using the Ishihara plates test.

The Ishihara plates test is one of the most established and widely used means of identifying color vision deficiencies. However, literature examining the effectiveness of the Ishihara plates test has identified weaknesses, particularly when screening for milder anomalous trichromacy. We constructed a model of the chromatic signals expected to contribute to false negative readings by calculating, for particular anomalous trichromatic observers, the differences in chromaticity between the ground and pseudoisochromatic portions of plates. Predicted signals from five plates were compared for seven editions of the Ishihara plates test, for six observers with three severities of anomalous trichromacy, under eight illuminants. We found significant effects of variation in all of these factors other than edition on the predicted color signals available to read the plates. The impact of edition was tested behaviorally with 35 observers with color vision deficiency and 26 normal trichromats, which corroborated the minimal effect of edition predicted by the model. We found a significant negative relationship between predicted color signals for anomalous trichromats and behavioral false negative plate readings (ρ=-0.46, p=0.005 for deuteranomals, ρ=-0.42, p=0.01 for protanomals), suggesting that residual observer-specific color signals in portions of plates designed to be isochromatic may be contributing to false negative readings, and validating our modeling approach.

Typical and Atypical Errors made by Color Normal and Defective Observers on Printed Pseudoisochromatic Color Vision Tests

Background: Pseudoisochromatic color vision tests are commonly used to screen for color vision deficiency (CVD). Although most color vision normal (CVN) individuals read all plates correctly, a remarkable proportion have errors. Objective: This study aimed to determine the typical and atypical error responses to the Ishihara and Waggoner PIP24 (W-PIP24) tests of CVN and CVD individuals. Methods: This study recruited 59 CVN and 63 congenital red-green CVD individuals. Participants were tested with the Ishihara and W-PIP24 tests. The participants’ responses were recorded, and typical and atypical errors were determined. Results: The rate of atypical errors in the CVN group was 21% in the Ishihara test and 9% in the W-PIP24 test, while those in the CVD group were 100% and 60%, respectively. The CVN and CVD groups tended to have more atypical errors on the Ishihara test than on the W-PIP24 test. Moreover, CVD individuals tended to have more atypical errors in the transformation plates in both tests. Conclusion: CVN individuals may misread the plates in the Ishihara and W-PIP24 tests for reasons other than the normality of color vision; therefore, counting only typical errors may eliminate the chance of CVN individuals misreading the number on the plates. The most significant finding of this study was that clinicians should perhaps only consider typical errors as “errors” on both tests.

Optical Coherence Tomography Angiography Parameters of the Retina in SARS-CoV-2 Recovered Subjects.

This study aims to evaluate retinochoroidal optical coherence tomography angiography (OCTA) parameters in patients recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This studywas an observational study that included 80 subjects being discharged after having negative reports on the reverse transcription-polymerase chain reaction (RT-PCR) test for SARS-CoV-2 to evaluate OCTA parameters of the retina. The subjects underwent an ophthalmic evaluation that included best-corrected visual acuity (BCVA), intraocular pressure (IOP), color vision (CV), contrast sensitivity (CS), and optical coherence tomography (OCT) parameters. OCTA was done for all patients and was evaluated for foveal avascular zone (FAZ) area, perimeter, and circularity index, and vessel density (VD) in superficial capillary plexus (SCP), deep capillary plexus (DCP), outer retina (OR), outer retina chorio-capillaries (ORCC), chorio-capillaries (CC), and choroid (C) using 3 x 3 mm scans. The OCTA parameters were compared with normative data of the Indian population for various parameters in question. The subjects included 54/80 (67.5%) males and 26/80 (32.5%) females having a mean age of 52.40 ± 15.71 (18-60) years. The systemic evaluation revealed 38.75% of subjects had hypertension, 30% had diabetes, 20% had kidney disease, 5% had tuberculosis, and 3.75% had coronary artery disease.The mean distance BCVA was logarithm of the minimum angle of resolution (LogMAR) (1.17 ± 0.22), mean IOP was 17.0 ± 4.0 mmHg, mean CS was 2.13 ± 0.36, 50.62% of subjects had normal CV on Farnsworth test while 47% had tritanopia, and none of the subjects had red-green CV defect on Ishihara plates. The OCT scan was normal in 90% of eyes while the posterior vitreous detachment was seen in 4% of eyes, broad vitreomacular adhesion in 2.5% of eyes, and the globally adherent epiretinal membrane was seen in 2.5% of eyes. The mean central macular thickness (CMT) measured 245.14 ± 28.41 micrometers. The mean FAZ area measured 0.37 ± 0.15 mm2, the perimeter was 3.28 ± 1.08 mm, and the circularity index measured 0.41 ± 0.10. The average VD in SCP measured 16.06 ± 12.29, in DCPmeasured 9.11 ± 8.75, in ORmeasured 6.38 ± 7.37, in ORCC measured 42.53 ± 12.46, in CCmeasured 25.83 ± 16.31, and in C measured 25.52 ± 17.49. The VD in coronavirus disease 2019 (COVID-19) subjects was significantly lesser than that in the healthy Indian population in all layers except ORCC. The SARS-CoV-2 recovered subjects have a reduced VD in retinochoroidal layersfrom COVID-19, an underlying systemic disease, or both. The CS values fall within normal limits. Several subjects show tritanopia on the Farnsworth test but no red-green CV defect on Ishihara plates.

Effects of eye dominance on shade matching and color perception among the dentist population.

The purpose of this study was to evaluate the influence of eye dominance on color perception, and shade matching. A total of 104 participants were selected for the study. There were 3 groups: Group I: 3rd and 4th year dental students and interns (n = 40); Group II: postgraduates (n = 34); Group III: senior residents and faculty members (≥ 6 years of clinical experience) (n = 30). All participants were evaluated for congenital color blindness with Ishihara plates, their dominant eye with Mile's test, and their color perception with the Farnsworth-Munsell 100 hue test. The shade guide test was used for shade matching with a second corresponding set of Vitapan classical shade guides. The results of Mile's test revealed that 60.6% were right-eye dominant and 39.4% were left-eye dominant. There was a statistically significant difference among all participants between the dominant eye and the non-dominant eye in shade matching. The dominant eye has a positive effect on shade matching and the ability to match shades becomes better with an increase in clinical experience.

Case report: Prolonged amelioration of mild red-green color vision deficiency following psilocybin mushroom use

Background Recent survey data indicate that some people report long-term improvement in color vision deficiency (CVD), also known as color blindness, following use of psychedelics such as lysergic acid diethylamide (LSD) and psilocybin. However, there are no objective data reported in the medical literature quantifying the degree or duration of CVD improvement associated with psychedelic use. Case presentation Here we present the case of a subject with red-green CVD (mild deuteranomalia) who self-administered the Ishihara Test to quantify the degree and duration of CVD improvement following the use of 5 g of dried psilocybin mushrooms. Self-reported Ishihara Test data from the subject revealed partial improvement in CVD peaking at 8 days and persisting for at least 16 days post-psilocybin administration. This improvement may have lasted longer, though the subsequent observations are confounded by additional substance use. Conclusion A single use of psilocybin may produce partial improvements in CVD extending beyond the period of acute effect, despite this condition typically resulting from a genetic defect. Systematic exploration of this possible phenomenon is needed to confirm our findings, gauge their generalizability, and determine the mechanism of action.

Fitness to Work Assessment for Oil Palm Fruits Harvest Workers Diagnosed with Color Blindness using Color Blind Test Media Based on the Color of Oil Palm Fruit.

Color blindness or color vision deficiency (CVD) is a disease that makes recognizing colors difficult or impossible. A person with color blindness may find it challenging to obtain employment, particularly in positions that need the ability to distinguish or see colors accurately. As the world's largest producer of palm oil, Indonesia employs a vast number of people in this industry. To discern between ripe and unripe oil palm fruit, harvesting jobs for oil palms is one of the occupations that require excellent color recognition skills. In the lack of a practical test method to determine the eligibility of a color blind oil palm fruit harvester, a simple yet effective test that can be modified for each enterprise is required.

Posterior Cortical Atrophy: Primary Occipital Variant

AbstractBackgroundPosterior Cortical Atrophy (PCA) is one of the atypical Alzheimer’s Disease (AD) variants, characterized by predominant visuospatial and visuoperceptual deficits, with dorsal and ventral subtypes recognized clinically and radiographically. A third primary occipital (caudal) variant has been suggested. The objective of this study was to determine its demographics, clinical manifestations, and biomarker findings.MethodFifty‐two PCA patients with positive amyloid PET scans were investigated. Patients underwent neuropsychological assessment, 3T MRI imaging and FDG‐, amyloid‐ and tau‐PET scans. Regional FDG‐PET values were normalized to the pons and represented as z‐scores relative to a control population. Patients were divided into “primary occipital” and “other PCA” subgroups according to FDG‐PET defined criteria, with primary occipital defined as patients in which the z‐scores for occipital subregions were at least one standard deviation lower (i.e., more abnormal) than the z scores in all other brain regions. Global amyloid‐PET, temporoparietal FDG‐PET and temporal tau‐PET regions‐of‐interest (ROI) were calculated. Student’s T test and Fisher’s exact analyses were used to investigate differences in demographics, clinical findings, and imaging biomarkers across the two groups.ResultNine patients were classified as primary occipital; primary occipital patients were older (64.8±6.9 versus 59.3±6.8, p=0.034) and had more years of education (17.7±1.7 versus 15.1±2.6, p=0.007) compared to the other PCA patients. Clinical evaluation revealed worse performance for the primary occipital group on the Ishihara test for color perception (p&lt;0.001), while the other PCA patients performed worse on the Western Aphasia Battery (WAB) praxis scale (p=0.005). Overall neuropsychiatric symptom burden as defined by the NPI‐Q was lower in the primary occipital group (p&lt;0.001). The FDG‐PET meta‐ROI (weighted median uptake in angular gyrus, posterior cingulate, and inferior temporal ROIs, normalized to the pons and vermis) was higher in the primary occipital subtype (p=0.006), but no differences were observed in amyloid and tau‐PET.ConclusionClinical and biomarker findings suggest primary occipital PCA is characterized by an older age at onset, more color perception dysfunction, less severe ideomotor apraxia and less hypometabolism in temporal‐parietal meta‐ROI compared to more established phenotypes.

Incidence of Color Blindness among Undergraduates Students of Medical College in Pokhara

Introduction: There are many genetic disorders that are X-linked, one being the color blindness. Some individuals affected with the disorders may remain unaware till detected for a long time. There are very few reports about the incidence of the color blindness among the medical undergraduate students. Objectives: Ojective of our study was to assess the color blindness incidence, among the medical undergraduates at the Gandaki Medical College, Pokhara. Methodology: We piloted an observational cross-sectional study among the first and second year medical students (MBBS, BDS, Nursing, and paramedics) at Gandaki medical college. We finalized 300 students of both the genders based on the inclusion criteria. We performed in the natural day light, the color vision test using the Ishihara plates. We assessed incidence, the type of the color blindness and the gender distribution among the subjects. We compared the data thus obtained applying the “chi square statistical test” deliberating p&lt;0.05 as significant. Results: We observed that all the colorblind subjects in the study were male who constituted 2% of the all the subjects. There was significant difference statistically among the types of the color blindness with majority having Deuteranomaly. Conclusions: We can conclude that incidence of the color blindness was exclusive among men in our study. Total color blindness was seen in majority of the male subjects. Screening the students will enable the unaware students of their disability and hence they can be guided to proper counseling.

RECOLORING ISHIMARA TEST IMAGE FOR PROTAN CVD PERSONS

In this paper, the effect of the protan CVD algorithm is analyzed. Using the protan CVD algorithm, theimages are recolored, so that they are suitable for use by protan CVD people. In the first part, a trichromaticanomaly of the protanomaly type is described. After that, the protan CVD algorithm is described. The second part ofthe paper describes the Experiment in which the effectiveness of the CVD algorithm was tested. The CVD algorithmwas applied to images from the Ishihara color blindness test database, which were purposely formed to detect protanCVD persons. The results of the Experiment are shown using images and numerical values of the average chromaticdifference between every two pixels of the image. Finally, a comparative analysis of the results using objective(analysis of chromatic differences) and subjective (visual inspection of the image) methods is presented. Based onthe analysis, an evaluation of the efficiency of the protan CVD algorithm was given.

Prevalence and awareness levels of color blindness among students of faculty of dentistry and dental prosthesis technology program.

The aim of this study was to evaluate the prevalence and awareness levels of color blindness among students in a faculty of dentistry and dental prosthesis technology program in two different universities. A survey of awareness of color blindness among 710 students (males: n=271; females: n=439) in the faculty of dentistry and dental prosthesis technology program of Gazi University and Ankara Medipol University in 2019-2021 was conducted. The color vision status of 442 of the students (males; n=155; females: n=287) was assessed using an online Ishihara color blindness test. The data obtained were subjected to statistical analysis using SPSS. There was no statistically significant difference in the color blindness scores in terms of sex (males: 0.75±0.84; females: 0.64±0.75) (p=0.226). The color blindness scores of the dental prosthesis technology students were statistically higher than those of the faculty of dentistry students (p=0.028). Education year was significantly associated with a compromised ability to identify colors properly (p=0.040). There was no statistically significant difference in terms of awareness levels of color blindness according to the number of years of education (p>0.005). In terms of the prevalence of color blindness, 2.2% of faculty of dentistry and dental prosthesis technology students had a moderate-to-high level of color blindness. Students' awareness of their own color vision status was very low. The educational content of faculty of dentistry and dental prosthesis technology programs on color blindness should be enriched.