Accommodation and vergence status among the 3rd and 4th graders in a mainstream school in Gauteng*

Abstract

Aim: The data presented in this paper is obtained from the study on the prevalence of visual deficien-cies in mainstream and learning disabled schools which revealed no difference in the prevalence of visual deficiencies in both schools. One of the objectives of this study was to determine the visual status of each learner in each of the two groups (mainstream and learning disabled). The findings of the study revealed that both groups presented with different visual deficiencies including accommodation, vergence deficiencies and poor ocular motilities which can contribute towards influencing the children’s learning skills negatively. The visual profile on the accommodative and vergence systems of the children from the mainstream school is further analysed in this paper to determine the prevalence of deficiencies in the 8-13 year-olds, and to support inclusion of the evaluation of these visual skills in the school vision screening protocol.Method: One hundred and twelve (112) children had an expanded vision screening, with eighty (80) from the mainstream school in Johannesburg aged 8-13 years. The expanded vision screeningincluded the measurement of visual acuity (Snellen Acuity), refractive error (static retinoscopy), accommodation (accuracy, facility and amplitude), evaluation of the vergence system (accuracy, facility and amplitude) and ocular motilities (direct ob-servation). Of the 80 children from the mainstream school, only 73 children’s results were consideredlearning performance of children, especially those of school-going-age. The study therefore supports the expanded vision screening of all school-going-children in South Africa to include visual efficiency skills (accommodation and vergence systems) for appropriate and early identification of the barriers and seven subjects were excluded due to their poor responses to the tests.Kolmogorov-Smirnov test was utilized to assess the normality of distribution of accommodative and vergence status of children from the mainstream school in Gauteng. Depending on the outcome of the normality, the T-test was used to analyse the data. The distribution of accommodative and vergence status (amplitudes and facilities) were found to be different from the normal distribution due to p-values found to be less than 0.05.Results: The results indicated that 12.3% had poor accommodation facility, 10% had poor accommodation amplitude, 17% had poor convergence amplitude and 21.9% had poor vergence facility. The prevalence of poor vergence facility was found to be 21.9%, higher than all the visual efficiency skills evaluated. However, the co-existence of both accommodative and vergence dysfunctions was not found, since subjects presented with either accommodative (isolated) or vergence (isolated) dysfunctions.Conclusion: The results considered were for tests performed subjectively, and therefore that could have led to the identified statistical outliers (due to inconsistent responses) in the analysis of data for the prevalence of poor accommodative (12.3%) and vergence (21.9%) facility. The prevalence of accommodative and vergence dysfunctions although low in some instances is a concern. There is definitely a need for early identification of visual deficiencies that can impact negatively on the to learning. (S Afr Optom 2012 71(1) 22-31)