Screening for Congenital Color Vision Deficiency in Primary Children in Port Harcourt City; Teachers\' knowledge and performance

Abstract

One hundred and thirty teachers were studied to evaluate their knowledge of congenital Color Vision Deficiency (CVD), and their ability to perform the Ishihara color vision test, so as to determine if they can provide color vision screening services for their pupils. The teachers were randomly selected from 13 schools in Port Harcourt City (PHC) and given a six hours training workshop on vision disorders in children and congenital color vision screening. They were given a self administered pre and post test questionnaires before and after training respectively. Subsequently, they screened 1,300 of their school pupils for congenital vision deficiency using the Ishihara color vision chart; and their results compared to that of the research team. Female teachers constituted 84.6% and males 15.4% of the study population. Seventy three teachers (53.8%) were from public schools while 46.2% were from private schools. Prior to the training workshop, only 6.2% of teachers had heard of the Ishihara color vision chart and none of the teachers could identify or knew how to use the chart. However with training there was significant improvement in knowledge of CVD. Comparison of the teachers' performance of color vision screening using the Ishihara chart to that of the research team showed a sensitivity of 67.6% with a specificity of 99.1%. The prevalence of congenital color vision deficiency in the 1,300 primary school screened was 2.6%, with males having a significantly higher prevalence than females. The study thus concludes that congenital color vision deficiency is prevalent amongst primary school children in Port Harcourt City, and with training, teachers can effectively perform color vision screening, and as such modify their teaching methods to accommodate the child with color vision deficiency.