The importance of prenatal factors in childhood blindness in India
Rahi, J.S.; Sripathi, S.; Gilbert, C.E.; Foster, A.
Developmental Medicine and Child Neurology 39(7): 449-455
1997
ISSN/ISBN: 0012-1622 PMID: 9285435 DOI: 10.1111/j.1469-8749.1997.tb07464.xDocument Number: 268974
A cross-sectional study of 1411 children 3-15 years of age attending schools for the blind in 9 states of India in 1993 investigated the causes of visual impairment. 113 of these children (8%) were severely visually impaired and 1205 (85%) were blind. Severe visual impairment or blindness was hereditary in 23% of cases, attributable to intrauterine factors in 2%, related to perinatal factors in 1%, acquired postnatally in 28%, and of undetermined etiology in 46%. The most common mode of inheritance in hereditary cases was autosomal recessive (52%). Retinal dystrophies and albinism together accounted for 84% of hereditary disorders. Vitamin A deficiency was implicated in 19% of cases. If children with congenital anomalies were combined with those in whom definite hereditary or intrauterine factors were identified, 47% of all cases of severe visual impairment and blindness in this study were attributable to prenatal factors. This rate increases to 60% if undetermined cases presumed to involve prenatal factors are included. The 4 major causes of visual impairment and blindness were vitamin A deficiency, congenital ocular anomalies, inherited retinal dystrophies, and cataract. There were variations in the relative importance of these causes by state. The observed pattern of causes of visual loss is intermediate between those seen in developed countries and the poorest developing countries. Strategies to combat childhood blindness in India should address both preventable and treatable causes. Of particular importance in India, given the high proportion of autosomal recessive disorders, is education about the risks involved in consanguineous marriages.