Prevalence and Severity of Color Vision Deficiency Among Turkish Children

Abstract

ABS TRACT Objective: To determine the prevalence of color vision deficiency, ratio of deutan/protan and the distribution of the severity of color vision deficiency among Turkish children and to evaluate the usability the Color Assessment and Diagnosis (CAD) test in children. Material and Methods: A total of 1374 children (627 girls and 747 boys) of age 6-16 years were included in this study. The first 15 plates of the Ishihara test were used to evaluate to screen for color defi- ciency. Those who made three or more errors had their color vision examined using the CAD test to determine the type and severity of color vision deficiency. The prevalence of color vision deficiency in boys and girls, ratio of deutan and protan deficieny and the distribu- tion of the severity of loss were calculated. The correlations of the CAD test result and number of mistakes on the Ishihara test with age were also evaluated. Results: Thirty seven boys (4.95%) and 3 girls (0.47%) made 3 or more errors and were categorized as having color vision deficiency. In total, 32 subjects completed the CAD test, 22 subjects (68.7%) were classified as deutan and 10 (31.2%) as protan with the ratio of 2.2:1. In terms of the CAD based color vision grading system for red-green deficiency 3 subjects (9.3%) were classed as color vision (CV) category 3, 5 subjects (15.6%) as CV category 4 and 24 subjects (75%) as CV category 5. There was no significant correlation between the CAD test result and number of mistakes on the Ishihara test with age (r=-0.075, p=0.684 and r=-0.191, p=0.295 respectively). Conclusion: The results reveal severe loss of red-green color vision in 75% of the children with color vision deficiency. The study also demonstrates that the CAD test can be used in children as young as six years.