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3.
Artigo em Português | PAHO | ID: pah-22629

RESUMO

A deficiencia de vitamin A e responsavel por alteracoes em tecidos epiteliais especializados podendo levar a xeroftalmia e cegueira nutricional. Alemdisto, em anos recentes foi demonstrado que ofrecer suplementacao com vitamina A a criancas pre-escolares, em areas onde a deficiencia e endemica, pode reduzir a mortalidade de 23 per cento a 30 percento em media. Os primeiros relatos de carencia de vitamina A e xeroftalmia no Brasil ocorreram em 1864 e 1883, em escravos mal alimentados. Neste seculo, durante as secas periodicas na regiao Nordeste, houve relatos de cegueira noturna e de outras lesoes oculares. Nas ultimas decadas, diversos estudos determinaram niveis de retinol serico ou hepatico (este ultimo em amostras de necropsias) demonstrando que a hipovitaminose A e um problema de saude publica no Nordeste. No inicio da decada de 1980 encontraram-se lesoes oculares por deficiencia de vitamina A tanto em estudos epidemiologicos em campo, nos estados da Paraiba e Rio Grande do Norte, como tambem atraves do acompanhamento dos casos atendidos na enfermaria do Hospital Universitario de Joao Pessoa, Paraiba. Dentre os fatores de risco para a xeroftalmia corneal destacaram-se o desmame precoce, a idade abaixo de 12 meses e as infeccoes. Recentemente a deficiencia de vitamina A tem sido descrita na regiao Nordeste tambem em epocas de safras regulares, embora a maioria dos casos de xeroftalmia e cegueira nutricional tenham sido registrados durante periodos agudos de seca. Nesta regiao a carencia nutricional e permanente e qualquer fator precipitante pode romper o fragil equilibrio resultante das adaptacoes fisiopatologicas a desnutricao


Assuntos
Deficiência de Vitamina A/epidemiologia , Deficiências Nutricionais/epidemiologia , Indicadores Básicos de Saúde , Fatores de Risco , Xeroftalmia/epidemiologia , Estudos Transversais , Brasil/epidemiologia
4.
Geneva; World Health Organization; 3 ed; 19945. 69 p. ilus.
Monografia em Inglês | PAHO | ID: pah-19120

RESUMO

Ocular manifestations of vitamin A deficiency, particularly night blindness, have been recognized since antiguity. Animal research and clinical observations early in the twentieth century indicated that vitamin A was important for numerous bodily functions: animals and humans deficient in vitamin A grew poorly, suffered more persistent or severe infections, and subsequently developed characteristic ocular problems termed "xerophthalmia" or "dry eye". By the early 1940s these readily apparent eye signs had been eliminated from wealthier countries through dietary interventions. In developing countries today, however, at least 5-10 million children developed xerophthalmia every year, of whom between a quarter and a half a million go blind


Recent data indicated that mortality rates are also increased amongh children with even mild vitamin A deficiency and that, in many areas, enhanced vitamin A intake can reduce the risk of mortality from childhood infections by up to 54 per cent. It is estimated that the deaths of al least one million children would be prevented each year if vitamin A status were improved...extension and further refinement of knowledge about the importance of vitamin A in child health and survival made it necessary to revised this manual. This greater understanding, combined with growing commitment by governments, enhances the feasibility of achieving the declared goal of eliminating vitamin A deficiency as a significant public health problema by the start of the next millennium


Assuntos
Deficiência de Vitamina A/prevenção & controle , Xeroftalmia , Manual de Referência , Deficiência de Vitamina A/epidemiologia , Xeroftalmia/dietoterapia , Fenômenos Fisiológicos da Nutrição do Lactente , Serviços Preventivos de Saúde/provisão & distribuição , População Rural , Mortalidade Infantil/tendências , Estudos Transversais , Países em Desenvolvimento , Saúde Pública/legislação & jurisprudência , Grupos de Risco
10.
Artigo em Espanhol | PAHO | ID: pah-34655

RESUMO

Although in the last decade outstanding research workers have published important reports on their studies, there is still not satisfactory work dealing with the clinical pathology of xerophthalmia


The essential feature of this disease and of hypovitaminosis A in man is xerosis whose ocular manifestations are roughness, rigidity, opacity, pigmentation, dryness, and absence of tearing


After reviewing the clinical and epidemiological evidence on the function of vitamin A in man and leaving aside the arguments provided by the concentrations of retinol and carotene in the serum and the tissues as well as histological studies, it appears that:


The only inequivocable clinical proof is epithelial changes in the external surface of the eye and functional changes of the retina


Epithelial xerosis of the conjunctiva and the cornea are due to keratinizing metaplasia which may be considered a differentiating regression. The exposed parts of the eye socket are especially affected. Hyperpigmentation typical of these parts is a secondary effect


After weaning, the dietetic problem is related to the ingestion and utilization of carotene rather than of retinol


The most commonly affected age group among the poor is children between the ages of 2 and 4; they are affected slightly later than the victims of protein malnutrition


Night blindness and xerophthalmia are often closely related; only during pregnancy ...(AU)


Assuntos
Xeroftalmia/diagnóstico , Xeroftalmia/epidemiologia , Cegueira Noturna/diagnóstico , Distúrbios Nutricionais , Programas de Nutrição , Índia , Egito , África
11.
Artigo em Espanhol | PAHO | ID: pah-34643

RESUMO

The ocular manifestations of hypovitaminosis A -known as Nutriophthalmopathy A (NOA)- involve the anterior segment of the eye, mainly the conjunctiva and the cornea. The eyes are more vulnerable in pre-school age, 2-4 years, but are rarely affected in the first year and above the fourth year


In the course of the survey carried out by WHO in 1962-1963 (in 37 countries of Asia, Africa and America) 2,532 children were examined in Latin America; of these children 14.7 per cent were malnourished and 1.5 per cent had NOA in varying degrees, mostly as ulcers, or keratomalacia but this percentage rose to 14 per cent among the malnourished only. The lesions were noted more frequently during the rainy season, when there is always an increase in gastrointestinal infections in children and that may have to do with the seasonal variations observed in NOA


The author classifies the eye lesions observed in seven stages, according to their severity: night blindness, Bitot's spots, conjunctivocorneal xeroxis, interstitial corneal infiltration, corneal ulceration, keratomalacia, sequelae


The clinical picture observed in NOA lends itself to a prognosis not only in regard to the eye but also to a life expenctancy. The first six stages represent the active stage of the disease and stage VII is a stationary one and the final outcome. The first four of these stages are reversible, the changes being amenable to ...(AU)


Assuntos
Deficiência de Vitamina A , Xeroftalmia/dietoterapia , Distúrbios Nutricionais , El Salvador
13.
Artigo em Espanhol | PAHO | ID: pah-33934

RESUMO

The purpose of this study was to review the problem of nutritional disorders of the eye; with that end in view, surveys were carried out between July 1962 and March 1963 in South and East Asia, in the Near East and Northern Africa, and in Mexico, Central America, and South America. The authors first examine the sources of information used, which included replies to specially prepared questionnaires; government statistics and hospital records; surveys (cases of xerophthalmia might be detected during the course of surveys of infectious diarrhea, especially shigellosis); vernacular names for this condition; and personal observations of the consultants. On analyzing the epidemiological aspects the authors point out that climatic conditions have less influence on the occurrence of xerophthalmia than might at first be thought; more important is the correct use of available foods. On the other hand, studies made in Vietnam showed that seasonal variations do have a significant influence, especially in places where changes in climate are more marked. Among the social and economic factors which play a role in the occurrence of xerophthalmia and other nutritional disorders of childhood, attitudes toward foods and especially their suitability for young children, mal-distribution of food in the family and the abandonment of breast feeding among the economically insecure have a profound effect. Etiologic


Assuntos
Xeroftalmia/dietoterapia , Hipervitaminose A
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