Prevalence of color vision deficiency and it’s relation with ABO blood group among medical students

Background: Normal human beings can appreciate color in all three of it’s attributes; Hue, intensity, and saturation. Human beings can perceive three primary colors, that is, red, green, and blue. Any defect in appreciation of colors is known as color vision deficiency (CVD). Complete inability to appreciate color is known as color blindness. The genes for red and green cone pigments are found in the q arm of the X chromosome. Hence, red and green CVD are inherited as X-linked recessive diseases. Blue CVD is autosomaly inherited. Blood groups are genetically inherited as well. Although it is a known fact that there is a preponderance of genetic diseases in subjects belonging to a specific blood group, no such study was available in Western Odisha as per our knowledge. This becomes more relevant as consanguineous marriages are a serious social problem in that part of Odisha. Aim and Objectives: Therefore, the study was undertaken to find out the prevalence of CVD among Medical students in Western Odisha and to find out it’s relation, if any, with ABO blood groups, as these two entities are genetically inherited. Record should be kept for future use, especially for counseling at the time of marriage and if necessary, to choose a subject for further study, where color detection does not play an important part. Materials and Methods: Prior permission was taken from the Institutional Ethics Committee to carry out this study. The study was carried out among the 1st–4th year medical students of V.S.S. Medical College and Hospital (n = 690) from August 2022 to October 2022. Ishihara test plates for color vision and agglutination method for ABO blood grouping were employed to get the prevalence of CVD and to get the percentage of subjects belonging to each blood group among those having CVD. The observations were noted carefully. Results: After careful screening, it was seen that 647 (93.76%) were normal, 42 (6.08%) had CVD, and 1 (0.14%) subject was completely color blind. All those affected were males. Distribution of blood group in CVD subjects showed 7 (16.27%) numbers belonging to blood group A, 22 (51.16%) belonging to blood group B, 1 (2.3%) belonging to blood group AB, and 12 (27.9%) belonging to blood group O. The only color blind student belonged to blood group B (2.3%). Conclusion: As medical students have to deal with colors throughout their career, the study helps the subjects to be aware of their condition early in their professional life. It also tried to find out the percentage distribution into ABO blood groups. A larger population should be included to get more accurate results.

Clinically relevant colour album test for the colour defective medical student

Purpose: To evaluate the impact of color vision deficiency (CVD) in medical undergraduates by a more clinically applicable test. Methods: Cross?sectional study of 31 students with CVD (Ishihara diagnosed) asked to identify subject?specific signs/tests requiring color identification on a customized medical multispecialty designed color album test (CAT). They were further subjected to Farnsworth D?15 testing. Results: The error score of CVD students (4 ± 3.2) on 39 plates of color album test was highly significant as compared to the error score of color normal (0.3 ± 0.6). The CAT depicted linear correlation with Farnsworth D?15 and emerged as a valid tool of assessment. Ishihara interpretation did not correlate with the clinical impact of CVD. Nature of error suggests that CVD students can anticipate problems in dermatology, pathology, hematology, microbiology, and biochemistry. Conclusion: Color album test is a more clinically relevant test for CVD doctors to identify specialties where they can anticipate difficulties

Prevalence Of Congenital Colour Vision Deficiency Among Secondary School Male Students In Almadina Almunawara (Saudi Arabia)

@#The aim of this cross-sectional study is to determine the prevalence of congenital colour vision defects among male secondary school students in Al-Madinah Al-Munawara city, Saudi Arabia. A total of 1154 male secondary school students were selected randomly through a multi-stage sampling method. Ishihara 24-plates was used to screen for colour blindness. The overall prevalence of congenital colour vision defects was 3.3% with 1% protanopes and 2.3% deuteranopes. The prevalence of congenital colour vision defect among Saudis was 2.48% and (5.48%) among non-Saudis. In conclusion, the prevalence of congenital colour vision defect among male secondary school students of Al-Madinah Al-Munawara city is comparable to previously reported in central Saudi Arabia, but lower than for Caucasian.

A simple modification of the Farnsworth-Munsell 100-Hue test for much faster assessment of color vision.

Purpose: The Farnsworth‑Munsell (FM) 100‑hue test is well known but is also time consuming, especially its analytical component. To reduce this needless time‑waste during precious working hours, a simple modification was devised. Design: Prospective, comparative, observational study. Materials and Methods: A transparent clear plastic carrier box replaced the opaque one, allowing ready digital photodocumentation of top and bottom without even opening the box, or handling/inverting the caps - 200 reportedly normals and 50 known color vision defectives could be easily tested on this modified‑FM and results stored, allowing rapid turnover. The captured scores with patient ID were analyzed, at leisure, outside hospital time, saving 45-60 minutes/ patient. After recording, the box was promptly handed over to the next subject for rearrangement. Times taken for test/patient were recorded. Results: Running time was reduced from 60-75 min to ~15 min/patient with no waste of invaluable lab hours. Turnover time is limited to capturing two photographs (~60 sec). The box is relatively cheap and easy to maintain. Conclusions: Our simplified FM 100‑hue test allowed rapid assessment of color visions with easy data storage of both top and bottom.

Prevalence of color-vision deficiency among male high-school students

@#Objective This study determined the prevalence of color-vision deficiency among male high-school students in a public school. Methods Male high-school students were screened for color-vision deficiency using 6 plates of the Ishihara pseudoisochromatic plates. All students with one or more errors were reexamined at a later date with the full 15 Ishihara plates and the Farnsworth D15 (FD15) test. A detailed history was taken and an ocular examination was conducted. Students who identified less than 10 plates correctly on the FD15 were classified as color-deficient and underwent the Farnsworth Munsell 100 hue (FM 100) test. The results were statistically analyzed. Results A total of 1,258 male high-school students, aged 12 to 16 years, were included in the study, 122 of whom failed the screening test. Of these, 106 completed the 15 Ishihara plates. Sixty-five failed and were classified as color-visiondeficient, of which 64 (98%) were deutans. Deutan was also the most common deficiency determined using the FD15 (78.95%) and FM100 (44.19 %) hue tests. Conclusion The prevalence of color-vision deficiency among male students in a public high school was 5.17% (65/1,258). The most common deficiency was the deutan type.

Color-vision abnormalities among patients undergoing tuberculosis treatment

Objective@#This study determined the incidence of and risk factors for color-vision abnormalities among Filipino patients undergoing directly observed treatment short-course (DOTS) for tuberculosis.@*Methods@#A prospective single-cohort study involving newly diagnosed patients with category-1 tuberculosis, recruited from DOTS health centers in Manila, was conducted. All patients were given a fixed-dose combination of rifampicin, isoniazid, ethambutol, and pyrazinamide for 60 days, after which treatment was continued with rifampicin and isoniazid for 4 more months. The participants underwent complete eye evaluation including color-vision testing and were followed up every month up to the conclusion of treatment.@*Results@#Out of 93 patients initially enrolled, 64 completed the prescribed follow-up and constituted the study group. Baseline color vision was normal. After 1 month of therapy, color vision tested with the Ishihara plates remained normal in all patients, but one failed the Farnsworth Panel D 15 and was classified as tritan while 30 (47.88%) failed the Lanthony Desaturated test. The type of abnormality was unclassified in 20 (66.67 %)patients and tritan in 10 (33.3%). Visual acuity remained unchanged from baseline. Repeat testing after ethambutol and pyrazinamide were stopped showed that color vision was normal using the Ishihara plates and the Farnsworth test, while 5 failed the Lanthony test. Of these, 3 were unclassified and 2 were tritan. In the 3rd to 6th months follow-up, no color-vision abnormalities were noted in the 3 tests. The only risk factor identified was age (p = 0.01) with older patients having a higher risk.@*Conclusion@#The incidence of color-vision abnormalities among patients undergoing DOTS was 47.88% using the Lanthony Desaturated test after an average of 39.66 days on quadruple anti-TB therapy. Age was the only significant risk factor observed. The color-vision abnormalities returned to normal within an average of 37.85 days after discontinuing ethambutol and pyrazinamide.

Color vision deficiency of three sisters in the same family / 国际眼科杂志(Guoji Yanke Zazhi)

· AIM: To evaluate genetic characteristics of congenital color vision deficiency of our medical student and her family subjects for establishing the mode of inheritance.· METHODS: Ishihara Pseudo-isochromatic Plate Test (IPPT)was used for determining the color vision deficiency and Farnsworth 100 Hue test (F100HT) was done for evaluating the type of color vision deficiency. Family pedigree was established for the color blindness, ophthalmologic examinations and genetic studies were done. Genetic counseling was given to her family.· RESULTS: Ocular examination revealed best correction bilateral visual acuity of 20/20 in both eyes, with myopic correction (-2.0D). Slit-lamp examination and intraocular pressure measurement were within normal limits and funduscopy revealed normal optic nerve, macula and retinal periphery. All other external ocular assessment and neurological examinations were normal. Proband's sisters and her parents' ophthalmic examinations were also normal. The error scores of three sisters and their father were found 19-20/25 in IPPT. The results were consistent as deutran of red-green color blindness. The chromosome analyses and ovarian cycles were both normal.· CONCLUSION: According to her family pedigree, her color blindness was due to X-linked recessive penetrance mode of inheritance.

Computer adapted Ishihara test in 104 students / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the validity of computer-adapted Ishihara test and the concordance with classic Ishihara test for the diagnosis of colour blindness. The sensitivity and the specificity of computer-adapted Ishihara test and potential usefulness of the test for detecting congenital colour blindness or colour vision deficiency were discussed.METHODS: Colour vision of 104 university students aged between 20 and 23 (median 21) years was evaluated by two methods. These methods are: 1) Individual test method based on computer-adapted Ishihara colour plates; 2) Individual test method based on classic method of exposing Ishihara colour printed plates. The capabilities of students perceiving colours were evaluated by these two different methods. The specificity, concordance and validity for the computer adapted Ishihara test method were investigated.RESULTS: There were 6 male and 1 female colour blind students. The pedigree of the female student proved to have a carrier mother and colour blind father. The incidence of colour blindness was 13.6 % (6/44) among males and 1.7%(1/60) for females. The incidence of colour blindness in whole population was 6.7 % (7/104). These students had not been aware that they have colour vision deficiency before our examination tests. Test results of students with normal colour vision and the students with colour blindness were compared as well as the two test methods in terms of concordance. The sensitivity and the specificity were both found to be 100 %and concordance was also found 100 %.CONCLUSION: Computer-adapted Ishihara test is digitally mastered, and remains true with respect to the basic concepts of color vision testing. It has obvious advantages over manual testing because its total test time and its error scores are standardized. It has been found 100% in agreement with the golden standard of classic Ishihara test. These features make this test original and dependable one.

Shift of Colorimetric Values in Ishihara Pseudoisochromatic Plates with Plate Aging

PURPOSE: This study aimed to quantify the shift of colorimetric values in the Ishihara pseudoisochromatic test with aging of the plates. METHODS: Three sets of Ishihara pseudoisochromatic plates with different published dates (printed in 1971, 1983 and 2001) were tested. Positions matching 32 dots with 13 colors were chosen from each set and the colorimetric values with the CIELAB and HSB/HLS color systems were measured with a spectrophotometer. Lightness (L*), red-green (a*), blue-yellow (b*), chroma, red hue, yellow hue, and green hue values from each set were compared. RESULTS: L* and chroma values were significantly higher in the older versions. The a* values shifted to red (increased a*) and the b* values shifted to yellow (increased b*) with plate aging. CONCLUSIONS: Our results showed that the pseudoisochromatic plates had significant changes in color values and a directional shift with aging.