Causes of Blindness and Severe Visual Impairment in Children in Chile

Abstract

SUMMARY Three hundred and eighteen of 421 children (76 per cent) registered in Chile's 10 schools for the blind were examined. 84 per cent of these had severe visual loss (severe visual impairment or blindness), which was attributable to hereditary factors in 29‐6 per cent, intra‐uterine factors in 8‐2 per cent, perinatal factors in 22‐5 per cent and childhood factors in 11‐2 per cent. The aetiology could not be determined in 28‐5 per cent. Retinopathy of prematurity (ROP) accounted for 17‐6 per cent of all children with severe visual loss; analysis of data by age‐group suggested that ROP is becoming an increasingly important cause of blindness. It is estimated that one‐half of the children with severe visual loss in Chile have avoidable causes of blindness. The findings are discussed in the light of possible control strategies. RÉSUMÉ Les causes de la cécité et̀ des troubles visuels graves chez les enfants chiliens Sur 421 enfants inscrits dans les 10 écoles pour aveugles du Chili, 318 (76 pour cent) ont été examinés. 84 pour cent d'entre eux avaient un déficit visuel grave (trouble visuel grave ou cécité). Les facteurs héréditaires intervenaient pour 29‐6 pour cent, les facteurs intra‐utérins pour 8‐2 pour cent, les facteurs péri‐nataux pour 22‐5 pour cent et les facteurs agissant durant l'enfance pour 11‐2 pour cent; l'étiologie ne put être fixée dans 28‐5 pour cent des cas. Une rétinopathie de prématurite (ROP) apparaissait pour 17‐6 pour cent de tous les enfants avec perte visuelle sévère; une analyse des données par groupe d'âge suggèrait que la ROP tend à devenir une cause d'importance croissante. On estime les causes de la cécité au Chili sont des causes évitables dans 49 pour cent des cas. Ces données sont discutees à la lumière de stragégies de contrôle possibles. ZUSAMMENFASSUNG Ursachen für Blindheit und schwere Sehstörungen bei Kindern in Chile Dreihundertundachtzehn (76 Prozent) von 421 Kindern, die in den 10 Blindenschulen von Chile registrtert sind, warden untersucht. 84 Prozent hatten einen schweren Sehverlust (schwere Sehstörungen oder Blindheit). Dieser hatte in 29‐6 Prozent eine heriditäre Ursache, in 8‐2 Prozent eine intra‐uterine, in 22‐5 Prozent eine perinatale und in 11‐2 Prozent eine im Kindesalter erworbene Ursache. In 28‐5 Prozent der Fälle war die Ätiologie nicht festzustellen. Eine Frühgeborenen‐retinopathie (ROP) war die Ursache bei 17‐6 Prozent aller Kinder mit schwerem Sehverlust; eine Datenanalyse nach Altersgruppen deutet darauf hin, daß die ROP als Ursache an Bedeutung gewinnt. Man nimmt an, daß bei 49 Prozent der Kinder mit schwerem Sehverlust in Chile die Ursache für die Erblindung vermeidbar gewesen wäre. Die Befunde werden unter dem Aspekt mdglicher Kontrollmafinahmen diskutiert. RESUMEN Causas de ceguera y de atteración visual grave en niños en Chile Se examinaron 318 (el 76 por ciento) de los 421 niflos registrados en 10 escuelas para ciegos de Chile. El 84 por ciento tenian una pérdida visual grave (alteratión visual severa o ceguera). El hecho era atribuible a factores h...

Pediatric and Adolescent Population With Visual Impairment: Study of 385 Cases

“…6 This discrepancy may be explained by the higher frequency of corneal injuries secondary to vitamin A deficiency and infections in African and Asian countries, where they account for up to 50% of the cases of blindness, and in Bolivia, the Dominican Republic, and Peru, where they account for 20%. 15,16 In the present study, the major cause of visual impairment was congenital glaucoma, due to the referral of patients to the Congenital Glaucoma Service of the Ophthalmologic Clinic. International data indicate that congenital glaucoma accounts for 6% of the cases of blindness in childhood worldwide.…”

“…In developing countries, available data on visual impairment, 4,5,15,16 are scarce, and do not reflect the magnitude of the problem of childhood visual impairment. 4,5 Studies conducted at visual impairment assistance services may contribute to the knowledge on the local characteristics and help with planning actions, although they represent only the part of the population that had access to care,.…”

“…In Latin America, studies on the causes of blindness have been conducted in schools for the blind. 15,16 In Brazil, a country of continental dimensions with diversified social, cultural, and economic characteristics, regional studies may show particular features of each area and service. Therefore, the present study aims at contributing to the recognition of the profile of the pediatric population with decreased visual response.…”

“…7,16,18,27 Technological advances have increased survival rates in very low birth weight preterm newborns, resulting in a higher incidence of ROP. 7,15,16 In Latin American countries such as Argentina, Cuba, and Paraguay, ROP accounts for one third to one half of the cases of blindness or profound low vision. 15 In the United States, its frequency is low, between 8% to 19% of the cases of blindness, thanks to better neonatal intensive care.…”

Global prevalence of childhood cataract: a systematic review

“…Previous reports from West Africa, South India, and Chile showed that lens abnormalities accounted for 15.5%, 7.4%, and 9.2% of blindness in such schools. 5 Similar studies conducted in Malawi, Kenya and Uganda found that blindness was caused by unoperated cataract in 13.1%, 9.1%, and 27.6% of children, respectively. 6 In Ethiopia, unoperated cataract or aphakia accounted for 9.2% of blindness in schools for the blind.…”