The causes of visual impairment in children in a school for the blind in Johannesburg - a cross sectional study

Abstract

Background: More than 1.4 million children are blind throughout the world. This is of significance due to the social, emotional and economic implications of childhood visual impairment, which are endured throughout a life time of “blind years”. Information regarding the epidemiology and risk factors relating to childhood visual impairment is essential for the development and implementation of targeted interventions, in order to reduce childhood blindness. Objectives: To identify the causes of childhood blindness in a school for the blind in Johannesburg, South Africa, as a representation of trends in our urban population, and to compare these findings with those of a similar study conducted in 1996, in order to inform health policy decision making. Methods: All learners attending a school for the blind in Johannesburg were evaluated. Information obtained was recorded using the World Health Organisation’s Programme for the Prevention of Blindness (WHO/ PBL) method and reporting form. Results: One hundred and eighty nine learners were examined, of which, 110 (58%) had severe visual impairment or blindness. The major affected anatomical sites were the retina (43%), whole globe (16%), optic nerve (10%), cornea (10%), uvea (6%) and lens related conditions (4%). Retinopathy of prematurity was the most common retinal condition (n=26, 14%). This has increased 11 fold (p<0.005) when compared to the findings in 1996. Hereditary and neonatal factors were responsible for visual impairment in 28% and 14% of learners respectively. Aetiology was indeterminate in 45% of learners. Avoidable causes accounted for 29% of learners with visual impairment which was significantly lower than findings from the previous study (p=0.016). Conclusion: There has been a substantial change in the disease pattern of childhood blindness, in this study population, compared to the findings of the previous study. While many advances have been made regarding immunisation, vitamin supplementation and ophthalmic management, the implementation of further measures are still required in order to overcome preventable causes of childhood visual impairment.