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In developing countries diseases such as vitamin A deficiency and measles lead to preventable or treatable blindness in children and the WHO’s VISION 2020 initiative, which gives priority to children, is aimed at prevention and treatment. Now a UK survey (
) has shown that in developed countries the scope for prevention and treatment may be limited.
During 2000 data were gathered from UK ophthalmologists and paediatricians through the British Ophthalmological and British Paediatric Surveillance Units. A total of 439 children under 16 years of age with newly diagnosed severe visual impairment or blindness (SVI-BL) were identified. An overall cumulative incidence to age 16 years of six per 10 000 children. Two thirds of the children were diagnosed in infancy. A quarter (96/408) were of low birthweight (<250 g) and 40% were from socially deprived families.
Diseases of the eye were not the main problem. More than three quarters (77%) had non-ophthalmic motor, sensory, or cognitive impairment, or chronic serious disease in addition to SVI/BL. Forty-four children (10%) died within 1 year of diagnosis. Infant mortality in children with SVI/BL was 119 per 1000. The anatomical site of disease causing SVI/BL was the eye in 208 children (47%), optic nerve in 123 (28%), and visual pathways or brain in 210 (48%). (One hundred children (23%) had disease at more than one site.) The most important causes were retinal and macular dystrophies (14%), optic atrophy (13%), optic hypoplasia (12%), hypoxic/ischaemic encephalopathy (12%), and unknown disorder of cerebral or visual pathways (21%). Retinopathy of prematurity caused only 13 cases (3%). The timing of the insult was assessed as prenatal in 268 (61%), perinatal or neonatal in 88 (20%), and later or unknown in 122 (28%). (Twenty-three children were allocated to more than one category.) The cause was hereditary disease in 144 children (33%), autosomal recessive in 90. Of the 76 children with postneonatal disease 18 had a tumour, 15 an infective cause, 12 hydrocephalus or raised intracranial pressure, 11 hypoxia/ischaemia, 9 nonaccidental injury, 3 accidental injury, and 8 systemic disorders (neurodegenerative 4, juvenile chronic arthritis 2, diabetes 2). The cause was classified as definitely preventable in 14 cases (retinopathy of prematurity, rubella), possibly preventable in 19 (autosomal dominant diseases, nonaccidental or accidental injury) and treatable in 75 (cataract, glaucoma, infections, raised intracranial pressure or hydrocephalus, and other treatable causes). Three hundred and thirty-one children (75%) had disorders not currently preventable or treatable.
Major causes of severe visual impairment or blindness in children in the UK at present are damage to cerebral/visual pathways and hereditary disease. Many children with SVI/BL have nonophthalmic problems and infant mortality is high. Only a quarter of the children have disease which is at present preventable or treatable.