Causes of blindness in children attending four schools for the blind in Thailand and the Philippines
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Using WHO definitions of visual loss and a standardised methodology, 256 children were examined in schools for the blind in Thailand (1 school) and the Philippines (3 schools). 244 (95%) were blind (BL) or severely visually impaired (SVI). Causes of SVI and blindness were classified anatomically and aetiologically, and avoidable causes identified.
Causes of visual loss in Khon Kaen, Thailand (n = 65) and Manila, Philippines, (n = 113) were similar, with conditions of the whole globe accounting for 27.7 and 27.4% of SVI/BL; retinal disease 29.2 and 23.0%; cataract 16.9 and 16.8%; corneal disease 12.3 and 13.4%; and optic nerve disease and glaucoma 6.2 and 8.8%. Perinatal factors accounted for 20.0 and 23.0% of SVI/BL; hereditary disease 13.8 and 17.7%; and 12.3 and 15.0% was due to events occurring during childhood. The underlying aetiology could not be determined in 50.8 and 41.6% of cases, respectively. In the two schools together twenty six children (15%) were blind from retinopathy of prematurity (ROP) and 16 (9%) from corneal scarring attributed to Vitamin A deficiency. 103 of 178 (58%) children had avoidable causes of visual loss.
In the Filipino towns of Baguio and Davao (n = 66), the causes of visual loss were different from those in Khon Kaen and Manila, with 54.8 and 42.9% of SVI/BL being due to corneal disease, and only 3.2 and 8.5% to retinal disease. Childhood factors were more important (61.3 and 57.1%) than hereditary (9.7 and 17.1%) or perinatal factors (0 and 2.9%). Thirty one children (47%) had SVI/BL attributed to Vitamin A deficiency. No child was blind from ROP. 42 of 66 (64%) of children had avoidable causes of blindness. Overall 60% of children with SVI/BL had avoidable causes of visual loss in these 4 schools. Approximately
half could have been prevented by primary health and eye care services and half could have been managed by surgical ophthalmological procedures. The causes of blindness identified in this blind school study suggest that the major causes are different for schools serving rural populations compared to those serving urban communities. Different control strategies are required for the different situations.
Key wordschildhood blindness retinopathy of prematurity Vitamin A deficiency
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- 1.Sommer A. Nutritional blindness. Xerophthalmia and Keratomalacia. Oxford University Press 1982.Google Scholar
- 2.Van Agtmaal EJ. Vitamin A proteins in tear fluid: a nutritional field survey on preschool children in Northeast Thailand. Thesis 1989.Google Scholar
- 3.Vitamin A news Notes. Winter 1990. Helen Keller International.Google Scholar
- 4.Vital News. 1990; 1.Google Scholar
- 5.Konyama K, Srisupan V. The causes of blindness in a rural province of Thailand. Trans APAO 1968; 3:146–54.Google Scholar
- 6.Gilbert CE, Foster A, Negrel AD, Thylefors B. Childhood blindness: a new form for recording causes of blindness and low vision in children. WHO Bulletin 1993 (in press).Google Scholar
- 7.Multicentre trial of cryotherapy for retinopathy of prematurity. One year outcome - structure and function. Cryothermy for Retinopathy of Prematurity Cooperative Group. Arch Ophthalmol 1990; 108:1408–16.Google Scholar
- 8.Foster A, Gilbert CE. Epidemiology of childhood blindness. Eye 1992; 6:173–6.Google Scholar
- 9.Goggin M, O'Keefe M. Childhood blindness in the Republic of Ireland: a national survey. Brit J Ophthalmol 1991; 75: 425–9.Google Scholar
- 10.Riise R, Flage T, Hansen E, Rosenberg T, Rudanko S-L, Voggosson G, Warburg M. Visual impairment in Nordic children. I Nordic registers and prevalence data. Acta Ophthalmologica 1992; 70:145–54.Google Scholar
- 11.Chirambo MC, Tielsch JM, West KP, Katz J, Tizazu T, Schwab L, Johnson G, Swartwood J, Taylor HR, Sommer A. Blindness and visual impairment in southern Malawi. Bull WHO 1986; 64: 567–72.Google Scholar
- 12.Faal H, Minassian D, Sowa S, Foster A. National survey of blindness and low vision in The Gambia. Brit J Ophthalmol 1989; 73: 82–7.Google Scholar