Wednesday, July 20, 2011

Childhood Blindness

As the causes of blindness in children differ from those in adults, different control measures are needed. In low-income countries, high proportions of children are blind due to preventable causes, which require community-based interventions. In all regions, children with treatable diseases, principally cataract, can have their sight restored. Childrens’ eyes cannot, however, be considered smaller versions of adults’ eyes, and specific expertise and equipment are required. Unlike adults, children require longterm follow-up after surgery, to manage complications and to prevent amblyopia (‘lazy eyes’). The understanding and involvement of parents is critical. In all regions, children with irreversible visual loss must be assessed for low-vision services, early visual stimulation, rehabilitation or special education, depending on their age and level of residual vision.

Current situation
It has been estimated that there are 1.4 million blind children in the world, 1 million of whom live in Asia and 300 000 in Africa (26). The prevalence ranges from 0.3/1000 children aged 0–15 years in affluent countries to 1.5/1000 children in very poor communities. Although the number of blind children is relatively low, they have a lifetime of blindness ahead, with an estimated 75 million blind-years (number blind × length of life), second only to cataract.

The same report showed that 500 000 children become blind each year (nearly one per minute). Many die in childhood from the underlying cause, such as measles, meningitis, rubella, prematurity, genetic diseases and head injuries. Most blind children are either born blind or become blind before their fifth birthday. Owing to demographic differences, the number of children who are blind per 10 million population varies from approximately 600 in affluent countries to approximately 6000 in very poor communities. About 40% of the causes of childhood blindness are preventable or treatable.

The causes of childhood blindness vary, but the main avoidable causes are:

  • corneal scarring in Africa and poorer countries in Asia;
  • cataract everywhere;
  • glaucoma everywhere;
  • retinopathy of prematurity in high- and middle-income countries and some cities in Asia;
  • refractive errors everywhere, but particularly in South-East Asia; and low vision, which encompasses visual impairment and blindness from untreatable causes, in all regions.

The main causes of blindness in children change over time. As a consequence of child survival programmes (for example, integrated management of childhood illness), corneal scarring due to measles and vitamin A deficiency is declining in many developing countries, so that the proportion due to cataract is increasing. Retinopathy of prematurity is emerging as an important cause in the middle-income countries of Latin America and eastern Europe and is likely to become an important cause in Asia over the next decade. The prevalence of refractive errors, particularly myopia, is increasing in school-age children, especially in South-East Asia.

Brought to you by http://successgain.info and http://successgain.us

No comments:

Post a Comment