Biomedical subjects
A Foster
Publications and source records attributed to A Foster.
Congenital rubella in south India: diagnosis using saliva from infants with cataract.
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Vulvar intraepithelial neoplasia in women infected with human immunodeficiency virus-1.
The purpose of this study was to determine the response of vulvar intraepithelial neoplasia (VIN) lesions to standard treatment methods in women infected with human immunodeficiency virus (HIV). We reviewed all cases of VIN over a 4-year period at an inner-city hospital. We reviewed the clinical records of these women to abstract demographic information as well as information about tobacco use, injection drug use, results of HIV testing, T cell count, stage of HIV infection, colposcopic and cytologic findings, treatment of lesions, and follow-up. Eight of the 28 women (29%) with VIN were infected with HIV. The relative risk for recurrence or persistence of VIN after treatment was 3.3 (95% confidence interval, 1.4-7.4; P = 0.01) in the HIV+ compared with the HIV- group. The high rate of HIV infection among women with VIN supports recommendation of HIV testing for women with VIN. Women known to have HIV infection should be carefully examined for vulvar lesions. Further study is needed to determine the optimum treatment for VIN in women infected with HIV.
[The prehospital anesthesia consultation in French speaking Switzerland].
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Penetrating keratoplasty in Africa: graft survival and visual outcome.
AIM: To study the survival and visual outcome of penetrating keratoplasty in an African setting. METHODS: A retrospective analysis of 216 corneal grafts, performed on 203 eyes of 186 patients, at Kikuyu Hospital, Kenya over a 5 year period. RESULTS: Half of the transplants were carried out for keratoconus with only 5% of the grafts being undertaken for corneal scarring caused by trachoma or measles. The average follow up was 27.3 months. The probability of graft survival at 2 years was 87.4% (95% CI 80.6%-94.3%) for keratoconus and 64.7% (95% CI 54.8%-74.6%) for other corneal pathologies. Forty seven grafts (21.8%) in 36 patients (17.7%) are known to have become opaque. The commonest causes of graft opacification were bacterial keratitis (6.0%), endothelial failure (6.0%), and graft rejection (5.1%). Preoperatively 55% of keratoconus eyes and 75.7% of non-keratoconus eyes were blind. Postoperatively, 5% of keratoconus eyes and 41.7% of the non-keratoconus eyes were blind. Normal vision was achieved in 53.7% of operated eyes. Grafts carried out for keratoconus had a better visual outcome than grafts performed for other corneal pathologies. Preoperatively, 12.4% of keratoconus and 48.5% of non-keratoconus patients were blind in their better eye. Postoperatively, 1.1% of keratoconus patients and 25.7% of non-keratoconus patients were blind. The number of patients with normal vision in the better eye increased from 32 (17.2%) to 106 (57.0%). Sight was restored to 34 blind patients, but two patients with severe visual impairment preoperatively were blind at their last follow up. There was therefore a net reduction of 32 in the number of blind patients after 216 keratoplasties. CONCLUSIONS: Penetrating keratoplasty can be successful in Africa, particularly for keratoconus and other corneal dystrophies. However, penetrating keratoplasty has a limited role in the treatment of blindness from corneal scarring due to trachoma, measles, and vitamin A deficiency for which community based preventive measures must remain the priority.
Aetiology of childhood cataract in south India.
AIM: To identify the causes of childhood cataract in south India with emphasis on factors that might be potentially preventable. METHODS: A total of 514 consecutive children with cataract attending an eye hospital outpatient clinic were examined and their parents interviewed by a trained interviewer using a standardised questionnaire in the local language. Serology was performed on children under 1 year of age to detect congenital rubella syndrome (CRS). Other investigations were performed as clinically indicated. RESULTS: Of the 366 children with non-traumatic cataract 25% were hereditary, 15% were due to congenital rubella syndrome, and 51% were undetermined. In children under 1 year of age 25% were due to rubella and cataract of nuclear morphology had a 75% positive predictive value for CRS. Mothers of children in the undetermined group were more likely to have taken abortifacients than a group of age matched controls (p = 0.1) but use of other medications in pregnancy was similar in both groups. Of the 148 (29%) children with traumatic cataracts three quarters were over the age of 6 years. Stick injuries were responsible for 28%, thorn injuries for 21%, and firecrackers for 5%. CONCLUSION: Nearly half of non-traumatic cataract in south India is due to potentially preventable causes (CRS and autosomal dominant disease). There is need for further work to identify the factors leading to childhood cataract in at least half of the cases for which no definite cause can as yet be determined.
Effect of thiopental, saffan, and propofol anesthesia on cardiovascular parameters and bronchial smooth muscle in the rhesus monkey.
The application of human pediatric equipment for measuring respiratory function in nonhuman primates is rapidly gaining popularity in the evaluation of anti-asthma drugs. An important difference between primate procedures and the human clinical situation is the requirement for anesthesia for some techniques because of poor animal compliance. We studied the actions of three potential maintenance anesthetic agents-thiopental, saffan, and propofol-and their effects on a range of cardiovascular parameters under conditions of a broncho-provocation test in rhesus monkeys. The spasmolytic effect of saffan on bronchial smooth muscle was investigated in smooth muscle preparations in vitro and in the rhesus monkey in vivo. Thiopental proved to be a useful sedating agent for this application. Saffan proved to be a bronchodilator in vitro, but the sedative dose was lower than that required to induce appreciable bronchodilator activity in vivo. In comparison, propofol was not appropriate for this application because of the poor sedative effect at nonbronchodilator doses.
Childhood blindness in India and Sri Lanka.
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Report of the Diabetic Foot and Amputation Group.
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Perinatal bereavement support for families and midwives.
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Ophthalmia neonatorum in developing countries.
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Myocardial atrophy in acquired immunodeficiency syndrome--associated wasting.
This study evaluated the effects of acquired immunodeficiency syndrome wasting syndrome (AWS) on the heart in a population free of overt opportunistic infection or clinical evidence of cardiac disease. Data from 53 patients with AWS and 16 healthy age-matched controls were studied. By echocardiography, a significant reduction in left ventricular mass was found in patients with AWS that remained significantly reduced when corrected for body surface area. Mean ejection fraction was within the normal range in patients with AWS but was significantly less than in controls. End-systolic volume index was slightly elevated in patients with AWS. Although no difference in end-systolic wall stress was seen, the end-systolic wall stress-shortening relation differed significantly. These findings are consistent with myocardial atrophy and subtle left ventricular dysfunction in patients with AWS.
Childhood blindness in India: causes in 1318 blind school students in nine states.
It is estimated that at least 200,000 children in India have severe visual impairment or blindness and approximately 15,000 are in schools for the blind. Although this represents a small percentage of the estimated 5 million blind in India, it is significant in terms of 'blind-years'. Strategies to combat childhood blindness require accurate data on the causes to allocate resources to appropriate preventive and curative services. Since socio-economic factors vary in different areas of this industrializing country data should be representative of the country as a whole. This is the first multi-state study to be undertaken in India using the Record for Children with Blindness and Low Vision from the World Health Organization/PBL Programme. A total of 1411 children in 22 schools from nine states in different geographical zones were examined by an ophthalmologist and optometrist. Of these, 1318 children were severely visually impaired or blind (SVI/BL). The major causes of SVI/BL in this study were: (1) corneal staphyloma, scar and phthisis bulbi (mainly attributable to vitamin A deficiency) in 26.4%; (2) microphthalmos, anophthalmos and coloboma in 20.7%; (3) retinal dystrophies and albinism in 19.3%; and (4) cataract, uncorrected aphakia and amblyopia in 12.3%. This mixed pattern of causes lies in an intermediate position between the patterns seen in developing countries and those seen in industrialised countries. The causes identified indicate the importance both of preventive public health strategies and of specialist paediatric ophthalmic and optical services in the management of childhood blindness in India.
Childhood blindness due to vitamin A deficiency in India: regional variations.
OBJECTIVES: To investigate the importance of vitamin A deficiency as a cause of childhood blindness and severe visual impairment (SVI) in India. DESIGN AND SETTING: Cross sectional survey of children with visual acuity less than 6/60 in the better eye (SVI/blindness), attending 22 schools for the blind in nine states of India. MAIN OUTCOME MEASURE: Proportion of children with blindness or SVI from corneal scarring attributable to vitamin A deficiency. RESULTS: 245 of 1318 (18.6%) of children had SVI/blindness attributable to vitamin A deficiency. The proportion of SVI/blindness due to vitamin A deficiency ranged from 7.5% (7/93) in Kerala to 26.7% (27/101) in Madhya Pradesh. In Tamil Nadu, 7.5% (9/120) of children in the capital city blind school had SVI/blindness due to vitamin A deficiency, compared with 30.4% (51/168) in a blind school in a rural area of the same state. CONCLUSION: Overall, vitamin A deficiency is the single most important cause of childhood blindness and SVI in India. There are marked variations by state and also between urban and rural locations.
Causes of childhood blindness in Sri Lanka: results from children attending six schools for the blind.
AIM: The survey aimed to identify the major treatable or preventable causes of visual loss in children attending blind schools in Sri Lanka so that appropriate control measures can be implemented. METHOD: A total of 226 children with blindness (BL) or severe visual impairment (SVI) attending six schools for the blind were examined and details recorded using the WHO standard reporting form. RESULTS: Cataract was responsible for 17% of BL/SVI and was the commonest 'avoidable' cause of childhood blindness. Bilateral microphthalmos accounted for one quarter of BL/SVI. Vitamin A deficiency was not a significant cause of visual morbidity. CONCLUSION: The pattern of childhood blindness seen in this study is typical of a growing number of south east Asian countries which are developing rapidly. Childhood cataract is a major avoidable cause that can benefit from future intervention strategies.
Low vision in east African blind school students: need for optical low vision services.
AIMS: There is increasing awareness of the needs of children with low vision, particularly in developing countries where programmes of integrated education are being developed. However, appropriate low vision services are usually not available or affordable. The aims of this study were, firstly, to assess the need for spectacles and optical low vision devices in students with low vision in schools for the blind in Kenya and Uganda; secondly, to evaluate inexpensive locally produced low vision devices; and, finally, to evaluate simple methods of identifying those low vision students who could read N5 to N8 print after low vision assessment. METHODS: A total of 230 students were examined (51 school and 16 university students in Uganda and 163 students in Kenya, aged 5-22 years), 147 of whom had a visual acuity of less than 6/18 to perception of light in the better eye at presentation. After refraction seven of the 147 achieved 6/18 or better. Eighty two (58.6%) of the 140 students with low vision (corrected visual acuity in the better eye of less than 6/18 to light perception) had refractive errors of more than 2 dioptres in the better eye, and 38 (27.1%) had more than 2 dioptres of astigmatism. RESULTS: Forty six per cent of students with low vision (n = 64) could read N5-N8 print unaided or with spectacles, as could a further 33% (n = 46) with low vision devices. Low vision devices were indicated in a total of 50 students (35.7%). The locally manufactured devices could meet two thirds of the need. CONCLUSION: A corrected distance acuity of 1/60 or better had a sensitivity of 99.1% and a specificity of 56.7% in predicting the ability to discern N8 print or better. The ability to perform at least two of the three simple tests of functional vision had a sensitivity of 95.5% and a specificity of 63.3% in identifying the students able to discern N8 or better.
Causes of childhood blindness in east Africa: results in 491 pupils attending 17 schools for the blind in Malawi, Kenya and Uganda.
Pupils attending 12 schools for the blind in Malawi, 3 schools in Kenya and 2 schools in Uganda were examined to determine the causes of severe visual impairment or blindness (visual acuity in the better eye of less than 6/60). A total of 491 pupils aged 3-22 years was examined. Visual acuity was measured in each eye using a Snellen E chart. The anatomical site of abnormality and underlying cause of visual loss were determined by clinical examination for each eye, and for the child. Information was recorded on a standard reporting form (the WHO/PBL Eye Examination Record for Children with Blindness and Low Vision). Data were analysed for those aged less than 16 years using a database which accompanies the form. Preventable and treatable causes were identified. 260 pupils aged 5-20 years were examined in Malawi, 163 pupils aged 3-19 years were examined in Kenya and 68 pupils aged 6-22 years were examined in Uganda. Of the 491 students included in the study 309 (62.9%) were blind (BL) and 69 (14.1%) were severely visually impaired (SVI). 244 were aged less than 16 years and had SVI/BL. In these 244 children 35.2% of visual loss was due to corneal pathology, 13.5% was due to cataract and 14.8% to diseases of the retina. Corneal pathology, attributed to vitamin A deficiency and measles infection in the majority, was responsible for proportionally more SVI/BL in students in Malawi than in Uganda or Kenya.(ABSTRACT TRUNCATED AT 250 WORDS)
Hereditary disease as a cause of childhood blindness: regional variation. Results of blind school studies undertaken in countries of Latin America, Asia and Africa.
There is evidence from developed countries that genetic disease is the major cause of childhood blindness. Little data are available from most developing and newly industrialised countries concerning the relative importance of hereditary diseases as a cause of childhood blindness. Children in schools for the blind in 13 countries of Africa, Latin America and Asia were examined between 1990 and 1994 using a standardised method The anatomical site of abnormality and underlying aetiology were analysed for children with a corrected acuity in the better eye of less than 6/60 (severe visual impairment and blindness, svi/BL). In these countries II-39% of svi/BL was attributed to genetic disease. Genetic diseases were responsible for a higher proportion of childhood visual loss in countries with higher levels of socio-economic development. An autosomal recessive mode of inheritance was reported in 22-52% of children with genetic disease. Retinal dystrophies were the commonest form of genetic eye disease (49-80%) in all countries apart from Thailand and the Philippines where cataract was the commonest (43.9%). The role of consanguinity, and opportunities for further research are discussed.