Prevalence, Causes, and Risk Factors of Visual Impairment in Emiratis and Non-Emiratis of Dubai: A Subnational Population-Based Cross-Sectional Survey.

Purpose: To study the prevalence, causes, and risk factors of visual impairment (VI) among the Dubai Emiratis and non-Emiratis. Methods: The survey was a population-based cross-sectional eye health study conducted 2019-2020. Cluster sampling was used to randomly select local (Emirati) and expatriate (non-Emirati) Dubai residents aged 40 years and older. Ocular examinations were conducted in selected eye clinics to determine the visual acuity (VA) and cause(s) of VI if any. Trained nurses, optometrists, and ophthalmologists did the examinations. VA was measured using ETDRS visual chart. The World Health Organization VI and blindness definitions and classifications for the cause(s) of VI were used. Results: A total of 892 participants were included in the final analysis. The mean age [SD] was 52.09 [9.48] years, with 55.8% as males. Prevalence of presenting mild, moderate, and severe VI was 4.7% (2.94-7.11%), 1.8% (0.78-3.5%), and 0% for Emiratis, and 3.6% (2.06-5.76), 1.6% (0.63-3.21), and 0% for non-Emiratis, respectively. Four Emirati participants were blind, with a prevalence of 0.9% (0.25%-2.28%). Men had lower likelihood of VI than women (odds ratio [OR] (95% CI): 0.42 (0.24-0.77)) after adjustment for covariates. Diabetes (OR (95% CI): 1.91 (1.04-3.52)) was an independent risk factor for VI. Higher education level was associated with a lower likelihood of VI (OR (95% CI): 0.34 (0.13-0.89). Leading causes of VI among Emiratis were uncorrected refractive error (52%) and cataract (17.2%). Glaucoma, optic atrophy, and absent globe were the causes of blindness. Conclusions: Prevalence of VI is comparably low with leading causes readily treatable. An effective strategy to improve spectacle correction and cataract services would reduce the VI burden.

Molecular characterisation of Rhipicephalus sanguineus sensu lato ticks from domestic dogs in Nigeria.

Rhipicephalus sanguineus is the most widely reported tick in the world. Molecular characterisation is important to verify its taxonomic status in the different parts of the world. In this study, we provide information on the molecular characterisation of R. sanguineus tick of dogs collected from Nigeria. Ticks were collected from 62 of 93 sampled dogs. The collected ticks were subjected to morphological identification with the aid of appropriate entomological keys. Deoxyribonucleic acid (DNA) was extracted from the most prevalent tick species (R. sanguineus) and was subjected to further molecular characterisation protocols. The partial mitochondrial 16S rRNA gene sequences (∼300 bp) were obtained from representative specimens. Data were statistically analysed using the chi-square (χ2 ) test. Phylogenetic analysis was performed including different lineages of R. sanguineus (sl) from Africa, Asia, Europe and America, and other species belonging to the R. sanguineus 'tropical lineage' (R. linnaei) as well as Rhipicephalus turanicus and Ixodes ricinus. Results of this study showed that R. sanguineus was the most abundant ticks of dogs with a prevalence of 61.8% (68/110; 95% CI = 52.5-70.54), followed by Amblyomma variegatum (20.0%) and Haemaphysalis leachi (18.2%). The molecular analysis shows that they are genetically different from the temperate strains but closely related to those from other West African countries. There is a need to establish the vector competence of this common Nigerian dog tick.

Keeping an eye on eye care: monitoring progress towards effective coverage.

The eye care sector is well positioned to contribute to the advancement of universal health coverage within countries. Given the large unmet need for care associated with cataract and refractive error, coupled with the fact that highly cost-effective interventions exist, we propose that effective cataract surgery coverage (eCSC) and effective refractive error coverage (eREC) serve as ideal indicators to track progress in the uptake and quality of eye care services at the global level, and to monitor progress towards universal health coverage in general. Global targets for 2030 for these two indicators were endorsed by WHO Member States at the 74th World Health Assembly in May, 2021. To develop consensus on the data requirements and methods of calculating eCSC and eREC, WHO convened a series of expert consultations to make recommendations for standardising the definitions and measurement approaches for eCSC and eREC and to identify areas in which future work is required.

Strengthening the integration of eye care into the health system: methodology for the development of the WHO package of eye care interventions.

OBJECTIVE: To describe the rational for, and the methods that will be employed to develop, the WHO package of eye care interventions (PECI). METHODS AND ANALYSIS: The development of the package will be conducted in four steps: (1) selection of eye conditions (for which interventions will be included in the package) based on epidemiological data on the causes of vision impairment and blindness, prevalence estimates of eye conditions and health facility data; (2) identification of interventions and related evidence for the selected eye conditions from clinical practice guidelines and high-quality systematic reviews by a technical working group; (3) expert agreement on the inclusion of eye care interventions in the package and the description of resources required for the provision of the selected interventions; and (4) peer review. The project will be led by the WHO Vision Programme in collaboration with Cochrane Eyes and Vision. A Technical Advisory Group, comprised of public health and clinical experts in the field, will provide technical input throughout all stages of development. RESULTS: After considering the feedback of Technical Advisory Group members and reviewing-related evidence, a final list of eye conditions for which interventions will be included in the package has been collated. CONCLUSION: The PECI will support Ministries of Health in prioritising, planning, budgeting and integrating eye care interventions into health systems. It is anticipated that the PECI will be available for use in 2021.

The status of childhood blindness and functional low vision in the Eastern Mediterranean region in 2012.

Childhood blindness and visual impairment (CBVI) are major disabilities that compromise the normal development of children. Health resources and practices to prevent CBVI are suboptimal in most countries in the Eastern Mediterranean Region (EMR). We reviewed the magnitude and the etiologies of childhood visual disabilities based on the estimates using socioeconomic proxy indicators such as gross domestic product (GDP) per capita and <5-year mortality rates. The result of these findings will facilitate novel concepts in addressing and developing services to effectively reduce CBVI in this region. The current study determined the rates of bilateral blindness (defined as  Best corrected visual acuity(BCVA)) less than 3/60 in the better eye or a visual field of 10° surrounding central fixation) and functional low vision (FLV) (visual impairment for which no treatment or refractive correction can improve the vision up to >6/18 in a better eye) in children <15 years old. We used the 2011 population projections, <5-year mortality rates and GDP per capita of 23 countries (collectively grouped as EMR). Based on the GDP, we divided the countries into three groups; high, middle- and low-income nations. By applying the bilateral blindness and FLV rates to high, middle- and low-income countries from the global literature to the population of children <15 years, we estimated that there could be 238,500 children with bilateral blindness (rate 1.2/1,000) in the region. In addition, there could be approximately 417,725 children with FLV (rate of 2.1/1,000) in the region. The causes of visual disability in the three groups are also discussed based on the available data. As our estimates are based on hospital and blind school studies in the past, they could have serious limitations for projecting the present magnitude and causes of visual disabilities in children of EMR. An effective approach to eye health care and screening for children within primary health care and with the available resources are discussed. The objectives, strategies, and operating procedures for child eye-care are presented. Variables impacting proper screening are discussed. To reach the targets, we recommend urgent implementation of new approaches to low vision and rehabilitation of children.

Mapping trachoma in 25 local government areas of Sokoto and Kebbi states, northwestern Nigeria.

INTRODUCTION: The WHO global initiative on elimination of trachoma by 2020 (GET 2020) recommends mapping of trachoma at district (Local Government Area (LGA)) levels to enable planning and control activities in affected communities worldwide. The aim of the present study was to provide baseline data on trachoma for the LGAs of Sokoto and Kebbi states, Nigeria. METHODS: A population-based cross-sectional survey was conducted in 25 LGAs between November 2011 and May 2012. The WHO guidelines for trachoma control and risk factor assessment were used in the planning and conduct of the survey. RESULTS: The prevalence of trachomatous inflammation-follicular in children aged 1-9 years ranged from 0.3% in Sokoto South to 15.6% in Kalgo LGA. The prevalence of trachomatous trichiasis (TT) in adults (>14 years) ranged from 0.03% in three LGAs to 0.6% in Gudu LGA. Logistic regression analysis for the trachoma risk factors after χ(2) analysis showed only distance from water source as a significant risk factor (OR>1, p<0.5). Clean face, access to latrines and knowledge of trachoma prevention were significantly protective (OR<1, p<0.5) against active disease. The average number of persons in need of TT lid surgery ranged from 0 in 3 LGAs to 397 in Danko-Wasagu LGA. Mass antibiotic distribution is needed in 4 LGAs. The estimated number of households in need of latrines and improved water sources are high, with 1 LGA requiring 34 500 latrines and 20 000 improved water sources. CONCLUSIONS: There is a burden of active trachoma of different endemicity levels in all the surveyed LGAs. The burden of trachoma risk factors remains a challenge despite the global effort to decrease the risk factors through the Millennium Development Goals.

Review of the publications of the Nigeria national blindness survey: methodology, prevalence, causes of blindness and visual impairment and outcome of cataract surgery.

This is a review of the major publications from the Nigeria national blindness survey in order to highlight major findings and challenges of eye care in Nigeria. The review summarizes methodology and key findings. Survey publications on methodology, prevalence and causes of visual impairment and outcome of cataract surgery were retrieved, reviewed and relevant data extracted, reported and discussed. The study was the largest and more detailed eye survey in Nigeria (15,375 people 40 years and older recruited). Participants had detailed eye examination including visual acuity, autorefractokeratometry, A- scan biometry, visual field and basic eye examination. Cause(s) of visual impairment in each eye using WHO algorithm was determined among participants with vision < 6/12. Some of the participants also had qualitative questions on barriers to uptake of services, quality of life and visual function. Major highlights of the results as contained in the publications include a high prevalence of blindness with 4.2% (95% CI: 3.8-4.6%;),of the study population having blindness (using presenting vision (PVA)) even with best correction the prevalence was 3.4% (95% CI: 3.0-3.8%. The prevalence of SVI using PVA was 1.5% (95% CI: 1.3-1.7%).and with best correction 0.8% (95% CI: 0.7-1.0%). Blindness varied by age groups, sex, literacy level and geopolitical zone. Furthermore, 84% of blindness was due to avoidable causes with cataract responsible for 43% of blindness, glaucoma 16.7%, uncorrected aphakia 8.4% and corneal opacity 7.9%. Of the total 538 eyes that had cataract surgery procedures, 42.7% had couching and the remaining had cataract surgery, but only 41.4% of cataract operated eyes had IOL surgery. Outcome of cataract surgery was good at presentation for only 30.8% of eyes (84 eyes) which improved to 56.8% with correction. The possible remedy for the high burden of needless blindness and harmful eye health practices in Nigeria are discussed.

Prevalence and causes of blindness and visual impairment in sokoto state, Nigeria: baseline data for vision 2020: the right to sight eye care programme.

PURPOSE: To estimate the prevalence of low vision and blindness, identify the causes, and suggest policies for an effective eye care program based on 2005 data from Sokoto State, Nigeria. MATERIALS AND METHODS: A stratified two-stage cluster sampling method was used to quantify the prevalence of blindness and the causes from 4 health zones in Sokoto State. Subjects were evaluated using a magnifying loupe, direct ophthalmoscope and torchlight. Data were collected based on the World Health Organization prevention of blindness coding for an eye examination. Prevalences with 95% confidence intervals (CI) were calculated and surgical coverage for causes of blindness was also analyzed. RESULTS: The response rate was 91%. The prevalence of bilateral blindness was 1.9% (95% CI: 1.5-2.3%) ranging from 1.6% to 2.0% across the four health zones. The prevalence was 2.1% (95% CI: 1.6-2.6%) in males and 1.6% (95% CI: 1.1-2.1%) in females. The leading cause of bilateral blindness was cataract (51.6%), followed by uncorrected aphakia (20.9%) and glaucoma (11%). The prevalence of bilateral operable cataract was 1.9% (95% CI: 1.5-2.3%). The cataract surgical coverage (individuals with visual acuity <6/60) for the study was lower than the couching coverage (4.4% vs. 14.9%, respectively). Surgical coverage for trichiasis was 4.4%. The major barrier to cataract and glaucoma management was cost. CONCLUSIONS: The prevalence of blindness in Sokoto State is high yet the main causes are largely avoidable. Barriers can be reduced by appropriate health education regarding the eye care program and the provision of integrated, sustainable, affordable and equitable services.

Prevalence, causes, and risk factors for functional low vision in Nigeria: results from the national survey of blindness and visual impairment.

PURPOSE: To estimate prevalence and describe causes of functional low vision (FLV) among a nationally representative sample of Nigerian adults, assess socioeconomic risk factors, and estimate the number of adults in Nigeria who might benefit from low vision assessment or rehabilitation services. METHODS: Multistage, stratified, cluster random sampling with probability proportional to size procedures were used to identify a nationally representative sample of 15,027 persons aged 40 years or older. Distance vision was measured using a reduced logMAR tumbling E-chart. All participants with presenting acuity of <6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause. FLV was defined as best corrected vision <6/18 in the better eye, after excluding those with no light perception in both eyes and those with treatable causes. Analysis took account of the clustered design. RESULTS: In all, 13,591 individuals were examined in 305 clusters (response rate, 89.9%). The crude prevalence of FLV was 3.5% (95% confidence interval, 3.1-3.9%). This was lower than the prevalence of blindness, which was 4.2%. Glaucoma was the most common cause and age the most important risk factor. There are estimated to be approximately 5000 adults with FLV per million population and 340 who are totally blind. Only 9.3% of those with FLV were of working age and literate. CONCLUSIONS: These are the first data on the prevalence, causes, and risk factors for FLV from Africa. Results support studies from Asia that the prevalence of FLV is lower than previously thought. Because the majority of adults with FLV in Nigeria live in rural areas and are elderly and not literate, further research is required to assess the nature of the interventions required and who might best deliver them.

Ecological determinants of blindness in Nigeria: the Nigeria National Blindness and Visual Impairment Survey.

OBJECTIVE: To determine the prevalence and causes of visual loss in different ecological zones across Nigeria. METHODS: A population-based survey using multi-stage, stratified, cluster random sampling with probability proportional to size comprising a nationally representative sample of adults aged > or = 40 years from six ecological zones. OUTCOME MEASURES: Distance vision was measured using reduced logMAR charts. Clinical examination included basic eye examination for all respondents and a detailed examination including visual fields, gonioscopy and fundus photography for those who were visually impaired or blind (i.e. presenting vision < 20/40 in the better eye). A principal cause of visual loss was assigned to all respondents with presenting vision < 20/40 in the better eye. RESULTS: A total of 15 122 persons aged > or = 40 years were enumerated, 13 599 (89.9%) of whom were examined. The prevalence of blindness varied according to ecological zone, being highest in the Sahel region (6.6%; 95% confidence interval (CI) 4.2 - 10.4) and lowest in the rain forest region (3.23%; 95% CI 2.6 - 3.9). Age/ gender-adjusted analyses showed that risk of blindness was highest in Sahel (odds ratio (OR) 3.4; 95% CI 2.1 - 5.8). More than 80% of blindness in all ecological regions was avoidable. Trachoma was a significant cause only in the Sudan savannah belt. The prevalence of all major blinding conditions was highest in the Sahel. CONCLUSIONS: The findings of this national survey may be applicable to other countries in West and Central Africa that share similar ecological zones. Onchocerciasis and trachoma are not major causes of blindness in Nigeria, possibly reflecting successful control efforts for both these neglected tropical diseases.

Assessment of right ventricular systolic function using tricuspid annular-plane systolic excursion in Nigerians with systemic hypertension.

AIM: Right ventricular (RV) systolic function in patients with hypertensive heart disease (HHD) is not well characterised. The primary aim of this study was to assess the systolic function of the right ventricle in patients with HHD using tricuspid annular-plane systolic excursion (TAPSE). METHODS: The study was cross-sectional in design and carried out in Kano, Nigeria. Patients were recruited if they had HHD on echocardiography and were at least 15 years of age. Patients with other cardiac pathologies such as ischaemic and valvular heart diseases were excluded. Patients were considered to have abnormal RV systolic function if they had reduced values of TAPSE ( < 15 mm). A p-value of < 0.05 was considered statistically significant. RESULTS: A total of 186 patients were serially recruited over seven months. Of these, 131 (70.4%) had normal RV systolic function (group 1) and 55 patients (29.6%) had abnormal function (group 2). Group 2 patients were older (p = 0.002) and had a higher prevalence of peripheral oedema (p = 0.002), moderate to severe dyspnoea, higher heart rate and lower left ventricular ejection fraction (p < 0.001). Atrial arrhythmias were also more prevalent among group 2 patients (p < 0.05). The best correlate to TAPSE was the septal mitral annularplane systolic excursion (r = +0.541, p < 0.001). Several variables such as age predicted the presence of reduced TAPSE. CONCLUSION: The study found that almost one-third of patients with HHD in Kano had RV systolic dysfunction as defined by reduced TAPSE, and these patients had a greater prevalence of factors associated with morbidity and mortality.

Couching in Nigeria: prevalence, risk factors and visual acuity outcomes.

PURPOSE: Couching is an ancient treatment for cataract which is still practiced in some of the poorer developing countries, particularly in sub-Saharan Africa. The purpose of this study is to describe risk factors for couching and visual acuity outcomes in a nationally representative sample of adults aged 40 years and above in Nigeria. METHODS: Probability in proportion size methods were used to identify a representative sample. Of the 15,375 adults enumerated, 13,582 were interviewed and examined. Examination included logMar acuities, slit lamp examination and dilated fundoscopy with digital fundus imaging. RESULTS: Almost half of the 583 eyes undergoing a procedure for cataract had been couched (249 eyes, 42.7%). Individuals living in rural areas (P = 0.033) and in the two underserved northern administrative zones (P = 0.33; P = 0.002) were more likely to have been couched. Visual outcomes were poor according to World Health Organization categories, with 55.8% of people and 73.1% of eyes having a presenting visual acuity of less than 3/60 and only 9.7% and 2.4% of people and eyes respectively having a good outcome (6/18 or better). None were wearing an aphakic correction, and with correction acuities improved but 42.6% of eyes were still blind (< 3/60). CONCLUSIONS: Couching is still widely practiced in Nigeria and visual outcomes are very poor. The population needs to be made aware of the risks associated with the procedure, and services for high quality, affordable cataract surgery need to be expanded, particularly in rural areas and in the north of the country.

Prevalence of blindness and low vision in north central, Nigeria.

BACKGROUND: The Kaduna State of Nigeria Eye Care Programme (KSECP) is a state-wide community-based eye care programme designed in the model of the World Health Organisation global initiative for the elimination of avoidable blindness by the year 2020--Vision 2020. OBJECTIVE: To provide baseline data for the monitoring and evaluation of the KSECP. METHODS: The study was a cross-sectional population-based survey that covered the state. A total of 8,400 people of all ages were planned to be examined across the three health zones of the state. The study population was selected by a stratified 2-stage cluster sampling technique, in which 120 communities across the health zones were randomly selected by probability proportional to size (PPS). In each chosen community 70 people of all ages were chosen randomly. Each selected person had visual acuity tested and eyes examined. Persons with vision worse than 6/18 in any of the eyes were assessed further to identify the cause(s) of visual impairment. RESULTS: The prevalence of blindness in the state was 0.6% (CI95% 0.4-0.8), while the prevalence of low vision was 3.2% (CI95% 2.8-3.6%). The main causes of blindness were cataract 14 (37.8%), glaucoma 8 (21.6%), and refractive error 3 (8.1%). The cataract surgical coverage (for persons) in the state for visual acuity less than 3/60 was 51.2%. Even then there were at least 6,854 people blinded by cataract in need of cataract surgical services across the state. CONCLUSION: Kaduna state has lower blindness prevalence than many neighbouring states. There is a huge unmet need in cataract, glaucoma and refractive error services in the state.

Environmental sanitary interventions for preventing active trachoma.

BACKGROUND: Trachoma is a major cause of avoidable blindness. It is responsible for about six million blind people worldwide, mostly in the poor communities of developing countries. One of the major strategies advocated for the control of the disease is the application of various environmental sanitary measures to such communities. OBJECTIVES: To assess the evidence for the effectiveness of environmental sanitary measures on the prevalence of active trachoma in endemic areas. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials - CENTRAL in The Cochrane Library (Issue 2, 2007), MEDLINE (1966 to July 2007), EMBASE (1980 to July 2007), LILACS (July 2007), reference list of trials and the Science Citation Index. We also contacted agencies, experts and researchers in trachoma control. SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials comparing any form of environmental hygiene measures with no measure. These hygiene measures included fly control, provision of water and health education. Participants in the trials were people normally resident in the trachoma endemic areas. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data and assessed the quality of trials. Study authors were contacted for additional information. Four trials met the inclusion criteria but meta-analysis was not conducted due to heterogeneity of the studies. MAIN RESULTS: Two studies that assessed insecticide spray as a fly control measure found that trachoma is reduced by at least 55% to 61% with this measure compared to no intervention. However, another study did not find insecticide spray to be effective in reducing trachoma. One study found that another fly control measure, latrine provision, reduced trachoma by 29.5% compared to no intervention; this was, however, not statistically significantly different. Another study revealed that health education on personal and household hygiene reduced the incidence of trachoma such that the odds of reducing trachoma in the health education village was about twice that of the no intervention village. However, all the studies have some methodological concerns relating to concealment of allocation and non-consideration of clustering effect in data analysis. AUTHORS' CONCLUSIONS: The role of insecticide spray as a fly control measure in reducing trachoma remains unclear. Latrine provision as a fly control measure has not demonstrated significant trachoma reduction. Health education may be effective in reducing trachoma. There is a dearth of data to determine the effectiveness of all aspects of environmental sanitation in the control of trachoma.

Patching for corneal abrasion.

BACKGROUND: Recent audits show that corneal abrasion is a common presenting eye complaint. Eye patches are often recommended for treating corneal abrasions despite the lack of evidence for their use. This systematic review was conducted to determine the effects of the eye patch when used to treat corneal abrasions. OBJECTIVES: The objective of this review was to test the hypothesis that patching an eye following a corneal abrasion improves healing or provides pain relief. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) on The Cochrane Library (2005, Issue 2), MEDLINE (1966 to April 2005), EMBASE (1980 to April 2005), LILACS (13 April 2005), NRR (2005, Issue 2) and SIGLE (December 2004). There were no language or date restrictions in the searches. We also searched the reference lists of included studies, unpublished 'grey' literature and conference proceedings and contacted pharmaceutical companies for details of unpublished trials. SELECTION CRITERIA: We included randomised and quasi-randomised controlled trials that compared patching the eye with no patching to treat simple corneal abrasions. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. We contacted investigators for further information regarding quality of trials. The primary outcome was healing of the corneal epithelium and secondary outcomes were related to pain. MAIN RESULTS: Eleven trials, which randomised a total of 1014 participants, were included in the review. Meta-analysis of seven studies with dichotomous healing outcomes favoured no patching on the first day of healing (risk ratio (RR) 0.89, 95% Confidence Interval (CI) 0.79 to 0.99). For days two and three there was no significant difference between the two groups. Of the nine trials that measured pain scores two favoured no patching and none favoured patching. Complication rates were low and no differences were noted in these between the two groups. No-patch groups generally received more adjuvant treatment with antibiotics and/or cycloplegics than the patch group which is an important confounding factor. AUTHORS' CONCLUSIONS: Treating simple corneal abrasions with a patch does not improve healing rates on the first day post-injury and does not reduce pain. In addition, use of patches results in a loss of binocular vision. Therefore it is recommended that patches should not be used for simple corneal abrasions. Further research should focus on large (greater than 10 mm(2)) abrasions.

Environmental sanitary interventions for preventing active trachoma.

BACKGROUND: Trachoma is the second or third major cause of blindness. It is responsible for about six million blind people worldwide, mostly in the poor communities of developing countries. One of the major strategies advocated for the control of the disease is the application of various environmental sanitary measures to such communities. OBJECTIVES: To assess the evidence for the effectiveness of environmental sanitary measures on the prevalence of active trachoma in endemic areas. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) on The Cochrane Library (Issue 4, 2004), MEDLINE (1966 to January 2005), EMBASE (1980 to January 2005), LILACS (April 2004), the reference list of trials and the Science Citation Index. We also contacted agencies, experts and researchers in trachoma control. SELECTION CRITERIA: This review included randomised and quasi-randomised controlled trials comparing any form of environmental hygiene measures with no measure. These hygienic measures included fly control, provision of water and health education. Participants in the trials were people normally resident in the trachoma endemic areas. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data and assessed the quality of trials. Study authors were contacted for additional information. Three trials met the inclusion criteria but meta-analysis was not conducted due to heterogeneity of the studies. MAIN RESULTS: Two studies that assessed insecticide spray as a fly control measure found that trachoma is reduced by at least 55% to 61% with this measure compared to no intervention. One study found that another fly control measure, latrine provision, reduced trachoma by 29.5% compared to no intervention; this was, however, not statistically significantly different. Another study revealed that health education on personal and household hygiene reduced the incidence of trachoma such that the odds of reducing trachoma in the health education village was about twice that of the no intervention village. However, all the studies have some methodological concerns relating to concealment of allocation and non-consideration of clustering effect in data analysis. AUTHORS' CONCLUSIONS: There is evidence that insecticide spray as a fly control measure reduces trachoma significantly. Latrine provision as a fly control measure has not demonstrated significant trachoma reduction. Health education may be effective in reducing trachoma. There is a dearth of data to determine the effectiveness of all aspects of environmental sanitation in the control of trachoma.

Face washing promotion for preventing active trachoma.

BACKGROUND: Trachoma remains a major cause of avoidable blindness among underprivileged populations in many developing countries. It is estimated that about 146 million people have active trachoma and nearly six million people are blind due to complications associated with repeat infections. OBJECTIVES: The objective of this review is to assess the effects of face washing on the prevalence of active trachoma in endemic communities. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group trials register) on The Cochrane Library (Issue 2, 2004), MEDLINE (1966 to February 2004), EMBASE (1980 to February 2004), the reference lists of identified trials and the Science Citation Index. We also contacted investigators and experts in the field to identify additional trials. SELECTION CRITERIA: We included randomised or quasi-randomised controlled trials, comparing face washing with no treatment or face washing combined with antibiotics against antibiotics alone. Participants in the trials were people normally resident in endemic trachoma communities. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed trial quality. Study authors were contacted for additional information. Two clinically heterogeneous trials are included, therefore a meta-analysis was considered inappropriate. MAIN RESULTS: This review includes two trials with data from a total of 2560 participants. Face washing combined with topical tetracycline was compared to topical tetracycline alone in three pairs of villages in one trial. The trial found a statistically significant effect for face washing combined with topical tetracycline in reducing 'severe' active trachoma compared to topical tetracycline alone. No statistically significant difference was observed between the intervention and control villages in reducing ('non-severe') active trachoma. The prevalence of clean faces was higher in the intervention villages than the control villages and this was statistically significant. Another trial compared eye washing to no treatment or to topical tetracycline alone or to a combination of eye washing and tetracycline drops in children with follicular trachoma. The trial found no statistically significant benefit of eye washing alone or in combination with tetracycline eye drops in reducing follicular trachoma amongst children with follicular trachoma. REVIEWERS' CONCLUSIONS: There is some evidence that face washing combined with topical tetracycline can be effective in reducing severe trachoma and in increasing the prevalence of clean faces. Current evidence does not however support a beneficial effect of face washing alone or in combination with topical tetracycline in reducing active trachoma.

Vitamin A deficiency in Nigeria.

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.

Magnitude of trachoma and barriers to uptake of lid surgery in a rural community of northern Nigeria.

AIMS: A population-based cross-sectional survey for trachoma prevalence was conducted in a subdistrict of northern Nigeria. The objectives of the survey were to determine the magnitude and pattern of trachoma and the barriers to uptake of lid surgery in the area. METHODS: A total of 2903 people of all ages were examined out of 3715 registered eligible persons. The study population was chosen by a two-stage cluster random sampling technique. Each person was examined for signs of trachoma. The World Health Organization (WHO) simplified trachoma grading was used. Persons with trichiasis that had not attended hospital were asked why they had not sought hospital treatment. RESULTS: A blindness prevalence of 1.5% (95% CI 0.4%-2.7%) was found in the study population. About 20% of the blindness were due to trachoma. The prevalence of trichiasis among women 15 years and above was found to be 8.6% (95% CI 6.8%-10.7%). The prevalence of active trachoma among children was 11.8% (95% CI 10.1%-13.3%). Over 90% of people with trichiasis have not sought medical attention. The major identified factor that prevents people from accessing hospital treatment for trichiasis was cost (57%). CONCLUSION: This study suggests that trachoma is of public health significance in this area; as such, an effective trachoma control program with emphasis on lid surgery should be established.

Trial of Trachoma Rapid Assessment in a subdistrict of northern Nigeria.

PURPOSE: To assess the usefulness of Trachoma Rapid Assessment (RA) in priority ranking of trachoma areas. METHODS: RA was conducted concurrently with a cross-sectional trachoma prevalence survey in some villages selected from the communities at risk for trachoma in the Kaita Local Government Area of northern Nigeria. The RA team consisted of two ophthalmic nurses. Pen torches and loupes were used for the examination. Data were collected on the seven components of the RA 'information pyramid' for all the selected villages. The data were analyzed using the RA methodology guidelines to determine the priority villages for trachoma intervention. This was compared with the ranking from the cross-sectional trachoma prevalence survey. RESULTS: The results of RA were found to be in agreement with the cross-sectional survey in 53.3% of the villages in the priority ranking of trichiasis, while in the priority ranking of active trachoma the agreement between the two methods was found to be 60%. The risk factors for trachoma were shown to be of high magnitude in all the villages using both the RA method and the prevalence survey. CONCLUSION: RA may be a more useful tool when applied to a vast area where the risk of trachoma is likely to differ greatly between different parts of the area. In the determination of the trichiasis pattern of a community by RA, it may be more useful to use the actual number of trichiasis cases in the area rather than the prevalence of trichiasis. The operational definition of some risk factor indicators seems very subjective and vague. The RA method needs more validation to sharpen the indicators used.