Prevalence of blindness in children

Abstract

Purpose: Calculate the prevalence of blindness in children in Western Australia. Methods: Blind children were identified either from the voluntary register of the Association for the Blind of Western Australia (List A) or from paediatric oph­thalmologists' clinics (List B). The cohort was defined as being legally blind on or before 30 September 2009 and born after 30 September 1991. Legal blindness was defined as having a best corrected visual acuity (BCVA) of LogMAR > 1 or < 10° diameter of visual field, or a combination of both reduced visual acuity and field restriction, resulting in an equivalent level of vision loss, in the better eye. Also included were chil­dren who could not fix or follow light, but whose acuity could not be measured. Using capture and recapture methods for 2 independent lists we esti­mated the population size and the 95% confidence intervals. Results: The estimated population of children who were blind in WA was calculated to be 110 (95% CI 81 to 139). This represents a prevalence of 0.02% of the population aged less than 18 years in 2009. Conclusions: There are few reliable data on the number of children who are blind. By using two overlapping and independent lists we have obtained an accurate estimate of the population size, consistent with published World Health Organization estimates. Less than half of the children who were legally blind were registered to receive rehabilitation and support services from the state provider.