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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A population-based study on the prevalence of blindness and low vision was carried out in Jimma Zone, south-western Ethiopia between November 1994 and January 1995. A total of 7423 people from a sample of 8215 (90.4%) was examined. Sixty-three (0.85%) were blind (visual acuity less than 3/60 in the better eye) and 125 people (1.7%) had low vision (less than 6/18-3/60). Cataract and aphakia (52.4%), corneal opacity and phthisis bulbi (25.4%), and glaucoma (9.5%) were the major causes of blindness. Cataract (56.8%), refractive errors (28.8%), and corneal opacity (12.8%) were the major causes of low vision. Corneal opacity from trachoma was responsible for 20.6% of all blindness and 10.4% of low vision. The prevalence of visual impairment due to refractive errors was 5.1/1000 population. Almost 25% of the study population had active trachoma, and 0.9% of pre-school children had signs of vitamin A deficiency. Out of a total population of 2 million an estimated 17,000 people are blind and 34,000 have low vision (i.e., a total of 51,000 people with visual impairment). Approximately 20,000 people require cataract surgery, 52,000 require lid surgery for trichiasis, 24,000 require spectacles (excluding presbyopia), including 10,000 for significant refractive errors, half a million require treatment for active trachoma and 4,000 require glaucoma treatment. Effective and feasible eye care programs need to be established in the zone and the available ophthalmic services have to be strengthened. These may be achievable through joint efforts of the community and the Ministry of Health in collaboration with non-governmental organizations. The available eye services are briefly described and recommendations made to meet the important needs for prevention of blindness in the region.
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PMID:Blindness and low vision in Jimma Zone, Ethopia: results of a population-based survey. 914 12

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.
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PMID:The importance of prenatal factors in childhood blindness in India. 928 35

Research is one of the four main activities of AITO. It is vital for the determination of health care priorities, and for the design, implementation, and evaluation of programs and projects in OCCCMED countries. Most of the research is surgical and focused on the diseases which cause blindness. Cataracts are the principal cause of blindness and have been the focus of many studies aimed at making surgery more accessible in terms of both geographical availability and cost. Trachoma is a major public health priority in the countries of the Sahel and a survey of its prevalence is underway in several countries. This study should lead to the development of preventive and curative treatments aimed at controlling blindness caused by trachoma by the year, 2020. Vitamin A deficiency, the cause of xerophthalmia and high mortality rates in infants, has been surveyed in several countries. A survey of glaucoma, another major cause of blindness which is often not recognized or treated, will be carried out in Bamako. Other studies focus on leprosy, malaria and the effects of visual disability on the quality of everyday life. It will be a major challenge over the next five years to develop the capacity within local populations to identify, design and implement research programs in community health aspects of ophthalmology that will take into account the needs and constraints of sub-Saharan Africa.
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PMID:[Research at the African Institute of Tropical Ophthalmology]. 964 37

The number of blind persons in the world is not accurately known. However, taking into account previous estimates by the World Health Organization and adjusting to the world population of 1990, it is likely that there are at least 35 million blind people if we apply the internationally accepted definition of blindness as vision less than 3/60 ( less than 20/400 or 0.05) in the better eye. If the threshold of vision less than 6/60 ( less than 20/200 or 0.1) is applied, the above figure can be increased by roughly 50%, ie, going well beyond 50 million blind people. To this somber picture should be added the effects of aging on populations in both developed and developing countries. Longer life expectancy is going to dramatically increase the need for eye care to prevent visual loss from such conditions as cataract, glaucoma, diabetic retinopathy, and macular degenerations. Corneal blindness, resulting mainly from trachoma and other infections, is apparently showing a downward trend, but there are still foci of severe disease. Thus the need for trichiasis surgery remains, and some recently evaluated techniques offer particularly good results. On the other hand, xerophthalmia due to vitamin A deficiency is still a major public health problem, causing both visual loss and increased mortality. It should be possible, by targeting ivermectin distribution programs to high-risk populations, to gradually eliminate onchocerciasis as a cause of blindness; however, the long-term sight-saving effect of ivermectin in cases of established ocular lesions needs to be confirmed.
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PMID:Epidemiologic aspects of global blindness prevention. 1015 Sep 65

Community ophthalmology requires a comprehensive approach for primary, secondary and tertiary prevention of all eye diseases like vitamin A deficiency, trachoma, measles, diabetic retinopathy, refractive errors, etc. Community ophthalmology is based on the principles of primary health care approach. Equitable distribution, community involvement, focus on prevention, appropriate technology and multisectorial approach are to name a few in primary health care approach. In India, National Programme for Trachoma Control was launched in 1963 and National Programme for Control of Blindness was launched in 1976. Prevention of blindness was included in 20-point plan in early 1980s. Increase in blindness was reassessed in 1986-89 and the strategy was changed. World Bank came to help in planning 11 million cataract operations in 7 years in 7 States where there was the highest prevalence of cataract. Departments of community ophthalmology have recently been developed in several institutions. If the problem of blindness is to be solved, extension of community-based approach including all strata of society is the need of the hour.
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PMID:Overview on community ophthalmology. 1064 80

The topic "nutrition and the eye" cannot adequately be covered in a single review article; indeed, dozens of books and hundreds of articles have been written on the subject. This review concentrates on three areas in which specific nutrients are known or theorized to have a major impact on vision and the visual system: vitamin A deficiency; antioxidants and their proposed role in the prevention of age-related cataract and macular degeneration; and nutritional optic neuropathies, including those of the recent Cuban epidemic. In addition, this article touches on nutritional treatments that have been suggested for several less common eye diseases and, finally, considers several less prevalent conditions in which deficiency of or excess exposure to a particular nutrient has been associated with ocular pathology.
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PMID:Nutrition and the eye. 1066 53

Corneal disease is the second most common cause of blindness in tropical countries after cataract. It mainly strikes children who are exposed to numerous infectious agents against which they are unprotected due to the absence of basic health care. In high risk groups, the incidence of childhood corneal-related blindness is more than 20 times higher than in developed countries. There are many causes of corneal-related blindness. Endemic trachoma persists in some areas and inflammatory forms can lead to blindness. Eradication requires instillation of antibiotics in the eye, improvement of sanitary conditions, and campaigns against promiscuity. Xerophthalmia can induce blindness by perforation of the cornea in children with vitamin A deficiency. Measles, herpes simplex keratitis, and corneal ulcer that progresses to bacterial or fungal infections, or to amebic keratitis are also major causes of corneal-related blindness. The incidence of onchocerciasis is decreasing thanks to treatment with ivermectin and programs to control simulium. Neonatal gonococcal ophthalmia and leprosy-associated ocular disease can also lead to blindness. This overview of the various causes illustrates the close correlation between the level of life and living conditions and the occurrence of corneal-related blindness in tropical areas.
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PMID:[Corneal blindness in tropical areas]. 1090 81

The encouraging scenario of international efforts to eliminate preventable and avoidable blindness is the legacy of public health ophthalmology in the 20th century. With active programs currently in place or beginning for the major cause of blindness in childhood and two of the leading infectious causes of blindness, it is natural that research in eye disease will shift even more heavily toward the leading causes of blindness in the older ages. The age-related eye diseases will rapidly become the most common causes of blindness and visual loss and, with the exception of cataract, are the more difficult to identify, diagnose, and treat. The human misery and social cost of blindness, especially in the countries that can ill afford it, are profound. To combat this problem, epidemiologic research in ophthalmology should look toward the following major areas: 1. the identification and testing of better screening modalities to determine early changes possibly amenable to preventive strategies. This includes detection of vitamin A deficiency as well. 2. the creation of uniform definitions for diseases, particularly glaucoma and early AMD, which have relevance for epidemiologic research into risk factors. 3. increased multidisciplinary research, working with investigators skilled in molecular genetics, biologic markers for age-related diseases, and those interested in new imaging and vision-testing techniques. 4. ongoing work in clinical trials of new approaches to prevent or delay the onset of vision loss from eye disease, including future vaccines for chlamydia and onchocerciasis. The major public health issue of blindness prevention will not disappear in the next century but only shift emphasis to different causes if the current programs achieve the success that is hoped. Future epidemiologic research will continue to require a concerted, sustained, and multidisciplinary effort in order to contribute to the vision research agenda in the next century.
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PMID:Looking forward to 20/20: a focus on the epidemiology of eye diseases. 1093 8

Childhood blindness is second only to cataract in magnitude of world blindness when the "blind years" is considered. The "blind years" is the number of years a person lives with blindness. Studies have shown that over 34%-69% of childhood blindness in Nigeria is caused by corneal opacity, which results mainly from an interplay of vitamin A deficiency, measles and harmful traditional eye practices. However, vitamin A deficiency which manifests in the eye as xerophthalmia is the dominant problem in these children. The purpose of this review is to stress the importance of xerophthalmia, which is of public health significance, as an important cause of childhood blindness in Nigeria. Studies involving surveys of xerophthalmia, childhood and nutritional blindness are reviewed with data extracted from a nationwide survey on prevalence of xerophthalmia. The likely explanation for vitamin A deficiency in Nigerian children is discussed with possible solutions and recommendations made to control this avoidable and devastating cause of blindness.
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PMID:Vitamin A deficiency in Nigeria. 1207 1

A descriptive study to determine the causes of low vision and blindness in children attending the Pacelli School for the Blind in Lagos State, Nigeria. A standardised methodology was used with structured and semi-structured questioinaires. Twenty-six children aged below 16 years who were identified as having low vision and blindness were examined to determine the causes of the low vision and blindness. The anatomical sites of diseases leading to low vision and blindness in these children were retina (30.8%), lens (23.1%), glaucoma (19.2%), cornea (11.5%) and optic nerve (7.7%). Aetiologically, 38.5% of low vision was due to hereditary factors, 23.1% intra-uterine, 15.4% others and unknown in 23%. Retinal dystrophy was the most common cause of low vision and blindness, while congenital cataract and glaucoma were the major causes of avoidable blindness. Very few cases of corneal scar (Measles/Vitamin A deficiency) were seen. The causes of low vision appeared to be different from those of blindness as hereditary and intra-uterine factors were mainly responsible for low vision. It is recommended that these children be identified early, through low vision care programmes and those with avoidable causes treated accordingly.
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PMID:Causes of low vision and blindness in children in a blind school in Lagos, Nigeria. 1208 49


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