Abstract
Purpose::
Reliable epidemiological data on the prevalence of severe visual impairment and blindness (SVI/BL) in children are difficult to obtain, but are essential for planning. No such data are available from Bangladesh. The aim of this study was to determine the prevalence of SVI/BL in children and to identify high prevalence areas and groups.
Methods::
Children (0-15 years) with presenting visual acuities of <6/60 in the better eye, who lived in 40 of the country’s 507 Thanas (sub-districts), were identified by a network of trained community volunteers (Key Informants). All eligible children were examined by ophthalmologists and the cause of visual loss determined using the WHO classification system. Population data were obtained from the 2001 census. Prevalence (per 1000 children) was calculated by age, sex and cause.
Results::
2,279 children with SVI/BL were identified. Total child population in the study Thana’s was 4,372,259. The overall prevalence of SVI/BL in children aged 0-15 years was 0.52 (95% CI 0.50-0.54), but there was considerable variation from Thana to Thana ranging from 0.25 in Chauhali and 0.94 in Singra (p<0.001).The prevalence was significantly different between the genders (p<0.001), being 0.63 (95% CI 0.60 -0.67) and 0.39 (95% CI 0.37 -0.42) in boys and girls respectively. The prevalence also significantly increased with age (p<0.001). The prevalence was 0.26 (95%CI: 0.23, 0.28), 0.53 (95%CI: 0.49, 0.56) and 0.88 (95%CI: 0.83, 0.93) in 0-5 years, 6-10 year and 11-15 year olds respectively.The cause specific prevalence of lens, corneal, whole globe anomalies and retinal related SVI/BL was 0.17 (95%CI: 0.16, 0.19), 0.09 (95%CI: 0.08, 0.10), 0.08 (95%CI: 0.07, 0.09) and 0.05 (95%CI: 0.05, 0.06) respectively.Boys had significantly higher odds of lens related blindness (OR: 2.0, 95%CI: 1.6, 2.4, p<0.001) and less odds of corneal blindness (OR 0.53, 95%CI: 0.43, 0.67) than girls.
Conclusions::
This is the first study in a defined population in Bangladesh, with a large number of blind children, to provide reliable prevalence data for program planners and policy makers. Extrapolating these figures to the country, there are at least 26,000 children who are currently SVI/BL. By identifying high prevalence Thanas, groups and causes, this study provides an opportunity to develop targeted strategies for prevention of blindness in children to achieve the goals of Vision 2020.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • visual development: infancy and childhood • low vision