A proposed rapid methodology to assess the prevalence and causes of blindness and visual impairment.

PURPOSE: To determine whether a sample of the 50-year-old and above population would provide comparable information to a total population-based survey. METHODS: In 1996, a national eye survey of the total population in The Gambia was undertaken and the results concerning the prevalence and distribution of blindness and low vision have been reported. The same data set was used to analyse the prevalence and causes of blindness and low vision in people aged 50 years and above, and to compare the findings with the total population. RESULTS: Of 55 bilaterally blind people in the total population, 83.6% were 50 years of age or older. The distribution by cause of blindness was similar for the total population and for those aged 50 years and above. Cataract and uncorrected aphakia accounted for 46% and 13%, respectively, in the total population and 48% and 15% in the 50 year and above age group. Trachoma accounted for 5% and 4%, and other corneal opacities for 16% and 13%, respectively. Phthisis bulbi, which may follow perforated corneal ulcers, ocular trauma/surgery or occasionally severe uveitis, accounted for 4% in both age groups, and glaucoma accounted for 9% in the total population and 11% in the 50 year plus group. CONCLUSION: Assessment of the 50 year and above age group proved to be a good indicator for the causes of blindness and visual impairment in the total population and for determining those causes of blindness that are avoidable. Such an assessment requires a much smaller sample size, less than 20% of the sample size for the total population, and is likely to be less expensive

Rapid assessment for prioritisation of trachoma control at community level in one district of the Kaolack Region, Senegal.

The objective of this study was to use a modified Lot Quality Assurance Sampling methodology to classify communities according to prevalence of active trachoma and to estimate the prevalence of trachoma and trichiasis in Nioro department, Kaolack Region, Senegal. A survey was conducted using two-stage cluster sampling to select 50 children aged 2-5 years in each of 33 clusters. In total 1,648 children were examined for active trachoma. Information on trachoma risk factors was collected through interviews with the mother or the household head of the child. Adults (>40 years) with trichiasis were identified through case finding. Nineteen clusters had a low prevalence of active trachoma in children aged 2-5 years (40%). The prevalence of active trachoma in children aged 2-5 years was 17.4% (95% CI 12.9-21.8%). Multivariate-adjusted predictors of active trachoma were: age, facial cleanliness, hygiene practices and keeping cattle in the household. The prevalence of trichiasis in adults aged over 40 years was 1.77% (95% CI 1.24-2.51), equating to 985 adults (95% CI 765-1250) with trichiasis in Nioro department. In conclusion, a survey using rapid methodology showed that trachoma is a problem of public significance in Nioro department, Senegal

Effects of probiotics on child growth : a systematic review

Peer reviewedPublisher PD

Transactions of the Royal Society of Tropical Medicine and Hygiene (2006) 100, 149—157 Rapid assessment for prioritisation of trachoma control at community level in one district of the

Summary The objective of this study was to use a modified Lot Quality Assurance Sampling methodology to classify communities according to prevalence of active trachoma and to estimate the prevalence of trachoma and trichiasis in Nioro department, Kaolack Region, Senegal. A survey was conducted using twostage cluster sampling to select 50 children aged 2—5 years in each of 33 clusters. In total 1648 children were examined for active trachoma. Information on trachoma risk factors was collected through interviews with the mother or the household head of the child. Adults (>40 years) with trichiasis were identified through case finding. Nineteen clusters had a low prevalence of active trachoma in children aged 2—5 years (<20%), 11 had medium prevalence (20—40%) and three had high prevalence (>40%). The prevalence of active trachoma in children aged 2—5 years was 17.4 % (95 % CI 12.9—21.8%). Multivariate-adjusted predictors of active trachoma were: age, facial cleanliness, hygiene practices and keeping cattle in the household. The prevalence of trichiasis in adults aged over 40 years was 1.77 % (95 % CI 1.24—2.51), equating to 985 adults (95 % CI 765—1250) with trichiasis in Nioro department. In conclusion, a survey using rapid methodology showed that trachoma is a problem of public significance in Nioro department

Effects of probiotics on child growth: a systematic review

Background: Child undernutrition has short and long term consequence for both individuals and society. Previous studies show probiotics may promote child growth and have an impact on under-nutrition. Methods: A systematic review of the literature was carried out on three electronic databases to assess evidence. The outcome measured was change in weight or height. A narrative analysis was conducted due to heterogeneity of included studies. Results: Twelve studies were included in the review of which ten were randomised controlled trials. A total of 2757 children were included, with 1598 from developing countries. The studies varied in type and quantity of probiotics given, duration of interventions, characteristics of participants, setting and units of outcome measures. Overall, five studies found a positive effect of probiotics on child growth. All five were conducted in developing countries with four studies conducted in mostly under-nourished children and one in well-nourished children. No significant effect on growth was found in the seven studies that were conducted in developed countries. Conclusion: The limited evidence suggests that probiotics have the potential to improve child growth in developing countries and in under-nourished children. More research is needed to explore this further

Correction of refractive error in the adult population of Bangladesh: meeting the unmet need.

PURPOSE: To assess the extent of uncorrected refractive error and associated factors in Bangladesh and to suggest ways in which this need can be met. METHODS: A nationally representative sample of 12,782 adults (>/= 30 years of age) was selected. Of them, 11,624 subjects underwent a demographic interview, visual acuity (logarithm of the minimum angle of resolution [logMAR]) measurement, automated refraction, and optic disc examination. Subjects with visual acuity less than 6/12 in either eye also had a corrected refraction measurement, cataract grading, and dilated retinal examination. RESULTS: Of the 11,624 subjects examined, 2,469 (22.1%) were myopes (less than -0.5 D) and 2,308 (20.6%) hyperopes (more than +0.5 D). The spectacle coverage percentage, calculated as [met need/(met need + unmet need) x 100%] was 25.2% and 40.5%, using 6/12 and 6/18 visual acuity cutoffs, respectively, and was higher in men and urban inhabitants. Older subjects and the literate and more highly educated were more likely to wear spectacles; however, most spectacle wearers (81%) had inadequate correction. Of the 1142 subjects who would benefit from spectacles, 827 (72.4%) would be suitable for off-the-shelf spectacles. Subjects without spectacles with less than 6/12 in the better eye (n = 835), would achieve 6/12 or better with correction (unmet need). Extrapolation to the national population yields an estimate that 1.5 million (6.7%) adult men and 1.8 million (9.2%) women have an unmet need for refractive correction. CONCLUSIONS: In Bangladesh, there is low spectacle coverage with a large unmet need. This survey identified risk groups, in particular women and those living in rural areas. This description of the availability of refractive services suggests areas for improvement (e.g., off-the-shelf spectacles) that may enable Bangladesh to achieve the goals of the World Health Organization's Vision 2020 initiative

Prevalence of blindness and visual impairment in Pakistan: the Pakistan National Blindness and Visual Impairment Survey.

PURPOSE: To determine the prevalence of blindness and visual impairment in adults aged 30 years and older in Pakistan and to assess socio-demographic risk factors. METHODS: Multistage, stratified (rural/urban), cluster random sampling, with probability proportional-to-size procedures, was used to select a nationally representative, cross-sectional sample of adults 30 years of age or older. Each subject was interviewed; had visual acuity measured (logMAR; logarithm of the minimum angle of resolution); and underwent autorefraction, biometry, and fundus-optic disc examination. Those with less than 6/12 acuity in either eye underwent a detailed ophthalmic examination, including corrected distance visual acuity measurement and dilated ophthalmoscopy. RESULTS: A nationally representative sample of 16,507 adults (95.5% of those enumerated) was examined. The age- and gender-standardized prevalence of blindness was 2.7% (95% confidence interval [CI], 2.4%-2.9%). It has been estimated that there are 1,140,000 (962,000-1,330,000) blind adults in Pakistan (2003 statistics). Blindness prevalence varied throughout the country, being highest in the provinces of Punjab and Baluchistan and lowest in the North West Frontier Province. Rural areas had a higher prevalence of blindness than did urban areas (3.8% vs. 2.5%, P < 0.001). Increasing age and being female were significantly associated with presenting visual acuity of <6/60 (odds ratio [OR], 2.5; 95% CI, 2.3-2.7 and 1.3; 95% CI, 1.1-1.5, respectively). Educational status was also associated with presenting visual acuity of <6/60. Subjects who had attended primary school were 60% (P < 0.001) less likely to have acuity of <6/60 than were subjects who had never been to school. CONCLUSIONS: This comprehensive survey provides reliable estimates of the prevalence of visual impairment and blindness in Pakistan. A significant excess of visual impairment was found among the elderly and the uneducated. After adjustment for age differences, women were found to have a significant excess of severe visual impairment and blindness. Regional variations in the prevalence of blindness were also identified

Lens opacities in adults in Pakistan: prevalence and risk factors.

PURPOSE: To investigate the prevalence and risk factors for lens opacity (LO) amongst a nationally representative sample of the adult population of Pakistan. METHODS: This national study of blindness and visual impairment (adults > or =30 years) used multistage, stratified, cluster random sampling. Grading of LO was conducted using the Mehra/Minassian classification system. LO, partly or wholly obscuring the red reflex, or previous cataract surgery were indicators of opacity. RESULTS: 16,402 (94.7%) adults were included in this analysis (study conducted 2002-2003). A total of 4,096 (standardized prevalence 20.9%, 95%CI: 20.3, 21.5%) adults were found to have LO. The highest prevalence of LO was found in Punjab province (22.2%), the lowest in Balochistan Province (18.0%). Significant positive associations were increasing age (multivariable odds ratio (OR) 3.2: 95%CI: 3.1, 3.4), hypertension (OR 1.2, 95%CI: 1.1, 1.3), history of diabetes (OR 2.6: 95%CI 2.0, 3.2) and smoking (OR 1.3: 95%CI: 1.1, 1.5). Higher body mass index (BMI) (OR 0.8: 95%CI 0.7, 0.9, heavy vs. normal BMI) and attendance to school (OR 0.6: 95%CI: 0.5, 0.8) were associated with lower risk of LO. Individuals in districts classified as hot were at significantly increased risk (OR 1.3: 95%CI: 1.1, 1.5), and those in wet districts (> 600 mm annual rainfall) had lower odds than individuals living in dry districts (OR 0.7: 95%CI: 0.6, 0.8). CONCLUSIONS: Almost a fifth of the adult population had LO. Significant positive associations were age, smoking status, hypertension, diabetes, and increased deprivation level. Protective factors included high BMI and educational achievement. The climatic associations offer novel hypothesis for further research into cataractogenesis

The Pakistan national blindness and visual impairment survey--research design, eye examination methodology and results of the pilot study.

PURPOSE: To establish age- and sex-specific prevalence rates and causes of blindness and low vision in children aged 10 to 15 years and adults aged 30 years and older in Pakistan. METHODS: Multi-stage, stratified (rural/urban), cluster random sampling, with probability proportional-to-size procedures, was utilised to select a cross-sectional, nationally representative sample of adults (16,600 subjects) and children (6,000 subjects). Each subject underwent: interview, visual acuity (logMAR), autorefraction and optic disc examination. Those that saw < 6/12 in either eye underwent corrected visual acuity and dilated posterior segment examination. RESULTS: The results of a pilot survey are reported in this paper. In the two rural pilot sites, 159 subjects (including 47 children) were examined; 50% were male. Thirty seven adults (23.3%) but no children saw worse than 6/12 in either eye. Two subjects were blind (corrected visual acuity) in the better eye, and 11 were visually impaired. Refractive error was the main cause (in 22 eyes (39% of the total of 56 eyes)) of < 6/12 visual acuity, followed by cataract (12 eyes), uncorrected aphakia (6 eyes) and age-related macular disease (3 eyes). CONCLUSIONS: The pilot survey demonstrated that the proposed examination process for the main survey is feasible. Particular strengths of this survey include the use of logMAR visual acuity testing and autorefraction of all subjects, a dilated posterior segment examination, and the use of a 'less than 6/12' threshold for further examination. This lower threshold addresses the burden of refractive error, which, with cataract, are two of the diseases specifically targeted by Vision 2020