Severe visual impairment and blindness in children in the UK.
BACKGROUND
Prevention of visual impairment and blindness in childhood is an international priority. However, many countries do not have contemporary information about incidence and causes, from which the scope and priorities for prevention and treatment can be identified.


METHODS
In the UK, children aged younger than 16 years newly diagnosed with severe visual impairment or blindness (SVI/BL, WHO criteria) during 2000 were identified through national active surveillance schemes in ophthalmology and paediatrics. From these data, we calculated yearly age-group specific incidence and cumulative incidence. Causes were classified by the anatomical site or sites affected and by timing of the insult or insults and causal factors, where known.


RESULTS
Of 439 newly diagnosed children, 336 (77%) had additional non-ophthalmic disorders or impairments (SVI/BL plus). Total yearly incidence was highest in the first year of life, being 4.0 (95% CI 3.6-4.5) per 10000, with a cumulative incidence by 16 years of age of 5.9 (5.3-6.5) per 10000. 10% (44) of all children died within 1 year of diagnosis of blindness. Prenatal causal factors affected 61% (268) of children, with perinatal or neonatal and childhood factors each affecting 18% (77). Incidence and causes varied with presence of non-ophthalmic impairments or disorders, birthweight, and ethnic origin. At least 75% (331) of children had disorders that were neither potentially preventable nor treatable, with current knowledge.


CONCLUSIONS
Severe visual impairment and blindness in childhood in the UK is more common, occurs more frequently in the context of complex non-ophthalmic impairments, and has greater associated mortality, than previously assumed. An increased rate in children of low birthweight and from ethnic minority groups, together with the observed diversity and complexity of the causes, reflect recent secular changes in the population at risk, specific risk factors, and strategies available for treatment.
Centre for Paediatric Epidemiology and Biostatistics and the Department of Ophthalmology/Visual Sciences Unit, Institute of Child Health, Great Ormond Street Hospital, UK. j.rahi@ich.ucl.ac.uk
Jugnoo S
JS
Rahi
Noriko
N
Cable
D001766:Blindness / Q000145:classification / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease / Q000145:classification; D019988:Children with Disabilities / Q000145:classification; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D006113:United Kingdom / Q000453:epidemiology; D014786:Vision Disorders / Q000145:classification / Q000175:diagnosis / Q000453:epidemiology*