Estimating the Intracluster Correlation Coefficient for the Clinical Sign "Trachomatous Inflammation-Follicular" in Population-Based Trachoma Prevalence Surveys: Results From a Meta-Regression Analysis of 261 Standardized Preintervention Surveys Carried Out in Ethiopia, Mozambique, and Nigeria.

Sample sizes in cluster surveys must be greater than those in surveys using simple random sampling in order to obtain similarly precise prevalence estimates, because results from subjects examined in the same cluster cannot be assumed to be independent. Therefore, a crucial aspect of cluster sampling is estimation of the intracluster correlation coefficient (ρ): the degree of relatedness of outcomes in a given cluster, defined as the proportion of total variance accounted for by between-cluster variation. In infectious disease epidemiology, this coefficient is related to transmission patterns and the natural history of infection; its value also depends on particulars of survey design. Estimation of ρ is often difficult due to the lack of comparable survey data with which to calculate summary estimates. Here we use a parametric bootstrap model to estimate ρ for the ocular clinical sign "trachomatous inflammation-follicular" (TF) among children aged 1-9 years within population-based trachoma prevalence surveys. We present results from a meta-regression analysis of data from 261 such surveys completed using standardized methods in Ethiopia, Mozambique, and Nigeria in 2012-2015. Consistent with the underlying theory, we found that ρ increased with increasing overall TF prevalence and smaller numbers of children examined per cluster. Estimates of ρ for TF were independently higher in Ethiopia than in the other countries.

Understanding the spatial distribution of trichiasis and its association with trachomatous inflammation-follicular.

BACKGROUND: Whilst previous work has identified clustering of the active trachoma sign "trachomatous inflammation-follicular" (TF), there is limited understanding of the spatial structure of trachomatous trichiasis (TT), the rarer, end-stage, blinding form of disease. Here we use community-level TF prevalence, information on access to water and sanitation, and large-scale environmental and socio-economic indicators to model the spatial variation in community-level TT prevalence in Benin, Cote d'Ivoire, DRC, Guinea, Ethiopia, Malawi, Mozambique, Nigeria, Sudan and Uganda. METHODS: We fit binomial mixed models, with community-level random effects, separately for each country. In countries where spatial correlation was detected through a semi-variogram diagnostic check we then fitted a geostatistical model to the TT prevalence data including TF prevalence as an explanatory variable. RESULTS: The estimated regression relationship between community-level TF and TT was significant in eight countries. We estimate that a 10% increase in community-level TF prevalence leads to an increase in the odds for TT ranging from 20 to 86% when accounting for additional covariates. CONCLUSION: We find evidence of an association between TF and TT in some parts of Africa. However, our results also suggest the presence of additional, country-specific, spatial risk factors which modulate the variation in TT risk.

Prevalence and causes of blindness and visual impairment in Kogi state, Nigeria-Findings from a Rapid assessment of avoidable blindness survey.

PURPOSE: To determine the prevalence and causes of blindness and visual impairment among adults in Kogi, Nigeria. METHODS: A Rapid assessment of avoidable blindness (RAAB) protocol was used with additional tools measuring disability and household wealth to measure the prevalence of blindness and visual impairment (VI) and associations with sex, disability, wealth, cataract surgical coverage and its effectiveness. RESULTS: Age- and sex-adjusted all-cause prevalence of bilateral blindness was 3.6% (95%CI 3.0-4.2%), prevalence of blindness among people living with additional, non-visual disabilities was 38.3% (95% CI 29.0-48.6%) compared to 1.6% (95%CI 1.2-2.1%; [Formula: see text] = 771.9, p<0.001) among people without additional disabilities. Cataract was the principal cause of bilateral blindness (55.3%). Cataract surgical coverage (CSC) at visual acuity (VA) 3/60 was 48.0%, higher among men than women (53.7% vs 40.3%); 12.0% among people with non-visual disabilities; 66.9% among people without non-visual disabilities, being higher among people in the wealthiest two quintiles (41.1%) compared to the lowest three (24.3%). Effective Cataract Surgical Coverage at Visual Acuity 6/60 was 31.0%, higher among males (34.9%) than females (25.5%), low among people with additional, non-visual disabilities (1.9%) compared to people with no additional disabilities (46.2%). Effective CDC was higher among people in the wealthiest two quintiles (411%) compared to the poorest three (24.3%). Good surgical outcome (VA>6/18) was seen in 61 eyes (52.6%) increasing to 71 (61.2%) eyes with best correction. Cost was identified as the main barrier to surgery. CONCLUSION: Findings suggest there exists inequalities in eye care with women, poorer people and people with disabilities having a lower Cataract Surgical Coverage, thereby, underscoring the importance of eye care programs to address these inequalities.

Accuracy, acceptability and feasibility of photography for use in trachoma surveys: a mixed methods study in Tanzania.

BACKGROUND: Photography could be used to train individuals to diagnose trachomatous inflammation-follicular (TF) as trachoma prevalence decreases and to ensure accurate field TF grading in trachoma prevalence surveys. We compared photograph and field TF grading and determined the acceptability and feasibility of eyelid photography to community members and trachoma survey trainers. METHODS: A total of 100 children ages 1-9 y were examined for TF in two Maasai villages in Tanzania. Two images of the right everted superior tarsal conjunctiva of each child were taken with a smartphone and a digital single-lens reflex (DSLR) camera. Two graders independently graded all photos. Focus group discussions (FGDs) were conducted with community members and Tropical Data trainers. RESULTS: Of 391 photos, one-fifth were discarded as ungradable. Compared with field grading, photo grading consistently underdiagnosed TF. Compared with field grading, DSLR photo grading resulted in a higher prevalence and sensitivity than smartphone photo grading. FGDs indicated that communities and trainers found photography acceptable and preferred smartphones to DSLR in terms of practicalities, but image quality was of paramount importance for trainers. CONCLUSIONS: Photography is acceptable and feasible, but further work is needed to ensure high-quality images that enable accurate and consistent grading before being routinely implemented in trachoma surveys.

Progress towards the elimination of trachoma in Nigeria.

Trachoma is targeted for elimination as a public health problem worldwide by 2030. In Nigeria, elimination activities are implemented at the local government area (LGA) level. They started in 2002 by conducting baseline population-based prevalence surveys (PBPSs), which continued in a systematic manner with engagement from the Global Trachoma Mapping Project in 2013, and subsequently Tropical Data. The results led to the development of Nigeria's first trachoma action plan and its subsequent revision with additional information. Following 449 baseline PBPSs, 122 LGAs had an active trachoma prevalence above the elimination threshold, requiring interventions, while 231 LGAs required community-based interventions for trichiasis management. By 2021, >34 million antibiotic treatments had been provided in 104 LGAs, with 89 LGAs eliminating active trachoma. Nationally, water and sanitation coverages increased by 3% and 18%, respectively, in 7 y. Systematic trichiasis case finding and management were carried out in 231 LGAs, resulting in the management of 102 527 people. Fifty-four LGAs decreased trichiasis prevalence unknown to the health system to <0.2% in persons ≥15 y of age. Where this elimination prevalence threshold was reached, trichiasis services were transitioned to routine eye/healthcare systems. Such progress relied on strong leadership and coordination from the national trachoma program and tremendous support provided by partners. Attaining elimination of trachoma as a public health problem in Nigeria by 2030 is feasible if funding support is sustained.

Baseline Prevalence of Trachoma in 21 Local Government Areas of Adamawa State, North East Nigeria.

PURPOSE: To determine the prevalence of trachoma in each of the 21 local government areas (LGAs) of Adamawa State, Nigeria. METHODS: A population-based cross-sectional survey was conducted in each of the 21 LGAs of Adamawa State between 2017 and 2019. With the support of Tropical Data (TD), surveys were planned and implemented in accordance with World Health Organization (WHO) recommendations. A two-stage cluster sampling technique was used in each LGA, 25 or 30 clusters were selected with a probability of selection proportionate to cluster size, and in each of these clusters, 25 or 30 households were enrolled for the survey. All residents aged 1 year and older within selected households were examined by TD-certified graders for trachomatous inflammation - follicular (TF) and trachomatous trichiasis (TT) using the WHO simplified grading scheme. Additionally, data were collected on household water and sanitation access. RESULTS: All 21 LGAs had TF prevalence in 1-9-year-olds below 5%. The prevalence of TT unknown to the health system in people aged ≥15 years was ≥0.2% in three of the 21 LGAs. Access to improved water and sanitation facilities was <80% in the majority of the surveyed LGAs. Only 12 of the 21 LGAs had ≥50% household-level improved latrine access, and only Yola North had ≥80% household-level improved latrine access. CONCLUSION: There is no need for mass treatment with antibiotics for trachoma elimination purposes in any of these LGAs. There is a need for active TT case finding and provision of community-based TT surgical services in three LGAs. Furthermore, engagement with water and sanitation agencies is needed to augment access to improved water and sanitation facilities across the State; this will help to avoid the recrudescence of active trachoma in the State.

Prevalence of Trachoma following Implementation of the SAFE Strategy in Three Local Government Areas of Taraba State, North Eastern Nigeria.

INTRODUCTION: In 2019-2020, one round of antibiotic mass drug administration (MDA) was implemented for trachoma elimination purposes in Donga, Gashaka, and Ussa local government areas (LGAs) of Taraba State, Nigeria, following baseline surveys in 2009 (Donga and Gashaka) and 2013-2014 (Ussa). Here, trachoma prevalence post-MDA in these three LGAs is reported. METHODS: In 2019 (Gashaka and Ussa) and 2020 (Donga), population-based, cross-sectional surveys were conducted following World Health Organization (WHO) guidance. A two-stage cluster sampling strategy was used. All residents of selected households aged ≥1 year were examined by Tropical Data-certified graders for trachomatous inflammation-follicular (TF) and trachomatous trichiasis (TT) using the WHO simplified trachoma grading scheme. Data on water, sanitation, and hygiene (WASH) access were also collected. RESULTS: A total of 1,883 households participated. From these households, 4,885 children aged 1-9 years were enumerated, and 4,866 (99.6%) examined. There were 5,050 eligible adults (aged ≥15 years) enumerated in the same households, of whom 4,888 (96.8%) were examined. Age-adjusted TF prevalence in children aged 1-9 years was 0.22% (95% CI: 0.00-0.65) in Donga, 0.0% in Gashaka, and 0.19% (95% CI: 0.00-0.44) in Ussa. The age- and gender-adjusted TT prevalence unknown to the health system in adults aged ≥15 years was 0.08% (95% CI: 0.00-0.19) in Donga, 0.02% (95% CI: 0.00-0.06) in Gashaka, and 0.10% (95% CI: 0.01-0.18) in Ussa. In Donga, Gashaka, and Ussa, respectively, 66%, 49% and 63% of households had access to an improved drinking water source, and 68%, 56% and 29% had access to an improved latrine. CONCLUSION: In all LGAs, the elimination thresholds for TF and TT unknown to the health system have been attained in the target age groups. These LGAs should be re-surveyed after 2 years to show that reductions in TF prevalence have been sustained in the absence of MDA. Health authorities should continue to improve WASH facilities to reduce the risk of later recrudescence.

Baseline Prevalence of Trachoma in 13 Local Government Areas of Borno State, Nigeria.

PURPOSE: We set out to determine the baseline prevalence of trachoma in 13 Local Government Areas (LGAs) of Borno State, Nigeria. METHODS: A population-based cross-sectional survey was conducted in each of 13 LGAs from 2017 to 2019, with the support of Tropical Data (TD). World Health Organization (WHO)-recommended protocols were used. With a probability-proportional-to-size systematic sampling method, 25 villages were selected per LGA in 2017 and 30 villages per LGA in 2019; in each village, 25 households were enrolled for 2017 surveys, while 30 were enrolled for 2019 surveys. All present, consenting residents aged ≥1 year were examined by TD-certified graders for trachomatous inflammation-follicular (TF) and trachomatous trichiasis (TT) using the WHO simplified grading scheme. Additionally, we collected data on household-level access to water, sanitation and hygiene (WASH) facilities. RESULTS: One LGA (Magumeri) had TF prevalence in 1-9-year-olds ≥10%; two other LGAs (Monguno and Kaga) had TF prevalence between 5.0% and 9.9%. The prevalence of TT unknown to the health system was ≥0.2% in six LGAs. The proportion of households with access to improved water sources ranged from 30% (Kwaya Kusar) to 95% (Monguno); household-level access to improved latrines was lowest in Shani (7%) and highest in Maiduguri (95%). CONCLUSION: Active TT case finding and strengthening of TT surgical services are needed in six LGAs. Mass drug administration (MDA) of antibiotics is needed in three LGAs to reduce the prevalence of active trachoma to below elimination thresholds. The trachoma elimination programme should engage WASH agencies to augment access to improved WASH facilities.

The Gambia Trachomatous Trichiasis Surveys: Results from Five Evaluation Units Confirm Attainment of Trachoma Elimination Thresholds.

INTRODUCTION: Trichiasis is present when in-turned eyelashes touch the eyeball. It may result in permanent vision loss. Trachomatous trichiasis (TT) is caused by multiple rounds of inflammation associated with conjunctival Chlamydia trachomatis infection. Surveys have been designed to estimate the prevalence of TT in evaluation units (EUs) of trachoma-endemic countries in order to help develop appropriate programme-level plans. In this study, TT-only surveys were conducted in five EUs of The Gambia to determine whether further intensive programmatic action was required. METHODS: Two-stage cluster sampling was used to select 27 villages per EU and ~25 households per village. Graders assessed the TT status of individuals aged ≥15 years in each selected household, including the presence or absence of conjunctival scarring in those with TT. RESULTS: From February to March 2019, 11595 people aged ≥15 years were examined. A total of 34 cases of TT were identified. All five EUs had an age- and gender-adjusted prevalence of TT unknown to the health system <0.2%. Three of five EUs had a prevalence of 0.0%. CONCLUSION: Using these and other previously collected data, in 2021, The Gambia was validated as having achieved national elimination of trachoma as a public health problem. Trachoma is still present in the population, but as its prevalence is low, it is unlikely that today's youth will experience the exposure to C. trachomatis required to precipitate TT. The Gambia demonstrates that with political will and consistent application of human and financial resources, trachoma can be eliminated as a public health problem.

Explaining the continuing high prevalence of trachomatous trichiasis unknown to the health system in evaluation units: a mixed methods explanatory study in four trachoma-endemic countries.

BACKGROUND: We explored reasons for continuing higher-than-anticipated prevalence of trachomatous trichiasis (TT) unknown to the health system in population-based prevalence surveys in evaluation units where full geographical coverage of TT case finding was reported. METHODS: A mixed-methods study in Ethiopia, Kenya, Nigeria and Tanzania was conducted. We compared data from clinical examination, campaign documentation and interviews with original trachoma impact survey (TIS) results. RESULTS: Of 169 TT cases identified by TIS teams, 130 (77%) were examined in this study. Of those, 90 (69%) were a match (both TIS and study teams agreed on TT classification) and 40 (31%) were a mismatch. Of the 40 mismatches, 22 (55%) were identified as unknown to the health system by the study team but as known to the health system by the TIS team; 12 (30%) were identified as not having TT by the study team but as having TT by the TIS team; and six (15%) were identified as unknown to the health system in the TIS team but as known to the health system by the study team based on documentation reviewed. CONCLUSIONS: Incorrectly reported geographical coverage of case-finding activities, and discrepancies in TT status between TIS results and more detailed assessments, are the key reasons identified for continuing high TT prevalence.

Impact of personal protective equipment on the clarity of vision among trachoma survey graders and trichiasis surgeons in the context of COVID-19.

BACKGROUND/AIMS: The COVID-19 pandemic necessitated the use of personal protective equipment for those involved in trachoma survey grading and trichiasis surgery. We sought to determine which configuration of a face shield would be less likely to impact grading accuracy and ability to conduct trichiasis surgery. The research also included assessment of comfort, ease of cleaning and robustness. METHODS: There were three research phases. In phase 1, assessment of four potential face shield configurations was undertaken with principal trachoma graders and trichiasis surgeon trainers to decide which two options should undergo further testing. In phase 2, clarity of vision and comfort (in a classroom environment) of the two configurations were assessed compared with no face shield (control), while grading trachomatous inflammation-follicular (TF). The second phase also included the assessment of impact of the configurations while performing trichiasis surgery using a training model. In phase 3, face shield ease of use was evaluated during routine surgical programmes. RESULTS: In phase 2, 124 trachoma graders and 28 trichiasis surgeons evaluated the 2 face shield configurations selected in phase 1. TF agreement was high (kappa=0.83 and 0.82) for both configurations compared with not wearing a face shield. Comfort was reported as good by 51% and 32% of graders using the two configurations. Trichiasis skill scores were similar for both configurations. CONCLUSION: The face shield configuration that includes a cut-out for mounting the 2.5× magnifying loupes does not appear to impact the ability or comfort of trachoma graders or trichiasis surgeons to carry out their work.

Changes in trachoma indicators in Kiribati with two rounds of azithromycin mass drug administration, measured in serial population-based surveys.

Baseline mapping in the two major population centers of Kiribati showed that trachoma was a public health problem in need of programmatic interventions. After conducting two annual rounds of antibiotic mass drug administration (MDA), Kiribati undertook trachoma impact surveys in 2019, using standardized two-stage cluster surveys in the evaluation units of Kiritimati Island and Tarawa. In Kiritimati, 516 households were visited and in Tarawa, 772 households were visited. Nearly all households had a drinking water source and access to an improved latrine. The prevalence of trachomatous trichiasis remained above the elimination threshold (0.2% in ≥15-year-olds) and was virtually unchanged from baseline. The prevalence of trachomatous inflammation-follicular (TF) in 1-9-year-olds decreased by approximately 40% from baseline in both evaluation units but remained above the 5% TF prevalence threshold for stopping MDA. TF prevalence at impact survey was 11.5% in Kiritimati and 17.9% in Tarawa. Infection prevalence in 1-9-year-olds by PCR was 0.96% in Kiritimati and 3.3% in Tarawa. Using a multiplex bead assay to measure antibodies to the C. trachomatis antigen Pgp3, seroprevalence in 1-9-year-olds was 30.2% in Kiritimati and 31.4% in Tarawa. The seroconversion rate, in seroconversion events/100 children/year, was 9.0 in Kiritimati and 9.2 in Tarawa. Seroprevalence and seroconversion rates were both assessed by four different assays, with strong agreement between tests. These results show that, despite decreases in indicators associated with infection at impact survey, trachoma remains a public health problem in Kiribati, and provide additional information about changes in serological indicators after MDA.

Exploring water, sanitation, and hygiene coverage targets for reaching and sustaining trachoma elimination: G-computation analysis.

BACKGROUND: Trachoma is the leading infectious cause of blindness. To reduce transmission, water, sanitation, and hygiene (WaSH) improvements are promoted through a comprehensive public health strategy. Evidence supporting the role of WaSH in trachoma elimination is mixed and it remains unknown what WaSH coverages are needed to effectively reduce transmission. METHODS/FINDINGS: We used g-computation to estimate the impact on the prevalence of trachomatous inflammation-follicular among children aged 1-9 years (TF1-9) when hypothetical WaSH interventions raised the minimum coverages from 5% to 100% for "nearby" face-washing water (<30 minutes roundtrip collection time) and adult latrine use in an evaluation unit (EU). For each scenario, we estimated the generalized prevalence difference as the TF1-9 prevalence under the intervention scenarios minus the observed prevalence. Data from 574 cross-sectional surveys conducted in 16 African and Eastern Mediterranean countries were included. Surveys were conducted from 2015-2019 with support from the Global Trachoma Mapping Project and Tropical Data. When modeling interventions among EUs that had not yet met the TF1-9 elimination target, increasing nearby face-washing water and latrine use coverages above 30% was generally associated with consistent decreases in TF1-9. For nearby face-washing water, we estimated a ≥25% decrease in TF1-9 at 65% coverage, with a plateau upon reaching 85% coverage. For latrine use, the estimated decrease in TF1-9 accelerated from 80% coverage upward, with a ≥25% decrease in TF1-9 by 85% coverage. Among EUs that had previously met the elimination target, results were inconclusive. CONCLUSIONS: Our results support Sustainable Development Goal 6 and provide insight into potential WaSH-related coverage targets for trachoma elimination. Targets can be tested in future trials to improve evidence-based WaSH guidance for trachoma.

Gender differences in the surgical management of trachomatous trichiasis: an exploratory analysis of global trachoma survey data, 2015-2019.

BACKGROUND: Trachomatous trichiasis (TT) is a painful, potentially blinding eye condition that can be managed through epilation or surgery. Women are affected by TT approximately twice as often as men and are believed to face gendered barriers to receiving surgical care to prevent vision loss. METHODS: We used data from 817 cross-sectional surveys conducted during 2015-2019 in 20 African countries to estimate the prevalence difference (PD) between female and male eyes for four outcomes potentially indicating gender-related differences in TT management: (1) received surgery and developed postoperative TT (PTT), (2) never offered surgery, (3) offered surgery but declined it, and (4) offered epilation but never offered surgery. RESULTS: The prevalence was modestly elevated among female eyes compared with male eyes for having PTT (PD:1.8 [95% confidence limits (CL): 0.6, 3.0]) and having declined surgery for the eye (PD: 6.2 [95% CL: 1.8, 10.7]). The proportion offered epilation was similar by gender (PD:0.5 [95% CL: -0.4, 1.3]), while never having been offered surgery was somewhat more prevalent among male eyes (PD: -2.1 [95% CL: -3.5, -0.7]). CONCLUSIONS: Our results suggest potential gender differences in TT management. More research is needed to determine the causes and implications of the observed differences.

Tropical Data: Approach and Methodology as Applied to Trachoma Prevalence Surveys.

PURPOSE: Population-based prevalence surveys are essential for decision-making on interventions to achieve trachoma elimination as a public health problem. This paper outlines the methodologies of Tropical Data, which supports work to undertake those surveys. METHODS: Tropical Data is a consortium of partners that supports health ministries worldwide to conduct globally standardised prevalence surveys that conform to World Health Organization recommendations. Founding principles are health ministry ownership, partnership and collaboration, and quality assurance and quality control at every step of the survey process. Support covers survey planning, survey design, training, electronic data collection and fieldwork, and data management, analysis and dissemination. Methods are adapted to meet local context and needs. Customisations, operational research and integration of other diseases into routine trachoma surveys have also been supported. RESULTS: Between 29th February 2016 and 24th April 2023, 3373 trachoma surveys across 50 countries have been supported, resulting in 10,818,502 people being examined for trachoma. CONCLUSION: This health ministry-led, standardised approach, with support from the start to the end of the survey process, has helped all trachoma elimination stakeholders to know where interventions are needed, where interventions can be stopped, and when elimination as a public health problem has been achieved. Flexibility to meet specific country contexts, adaptation to changes in global guidance and adjustments in response to user feedback have facilitated innovation in evidence-based methodologies, and supported health ministries to strive for global disease control targets.

Does inter-border conflict influence the views of task sharing among community health volunteers in Nigeria? A qualitative study.

BACKGROUND: Volunteer community health workers are increasingly being engaged in Nigeria, through the World Health Organization's task sharing strategy. This strategy aims to address gaps in human resources for health, including inequitable distribution of health workers. Recent conflicts in rural and fragile border communities in northcentral Nigeria create challenges for volunteer community health workers to meet their community's increasing health needs. This study aimed to explore the perception of volunteers involved in task sharing to understand factors affecting performance and delivery in such contexts. METHODS: This was a qualitative study conducted in fragile border communities in north central Nigeria. Eighteen audio recorded, semi-structured interviews with volunteers and supervisors were performed. Their perceptions on how task sharing and allocation of tasks affect performance and delivery were elucidated. The transactional social framework was applied during the thematic analysis process to generate an explanatory account of the research data, which was analysed using NVivo software. RESULTS: Promotive and preventive tasks were shared among the predominantly agrarian respondents. There was a structured task allocation process that linked the community with the health system and mainly cordial relationships were in place. However, there were barriers related to ethnoreligious crises and current conflict, timing of task allocations, gender inequities in volunteerism, shortage of commodities, inadequate incentives, dwindling community support and negative attitudes of some volunteers. CONCLUSION: The perception of task sharing was mainly positive, despite the challenges, especially the current conflict. In this fragile context, reconsideration of non-seasonal task allocations within improved community-driven selection and security systems should be encouraged. Supportive supervision and providing adequate and timely renumeration will also be beneficial in this fragile setting.

Survey of Blindness in Saki East, Oyo State, Nigeria.

Background: This survey was undertaken in a rural local government area (LGA) where eye care services recently commenced, with no known previous data on blindness or visual impairment. Aim and Objectives: The aim was to generate evidence for further planning and monitoring of the on-going eye care program. The objectives included determination of the prevalence of blindness and visual impairment, causes of blindness and visual impairment, and assessment of cataract services and barriers to cataract surgery uptake. Materials and Methods: This was a cross-sectional observational study. A population-based rapid assessment of avoidable blindness (RAAB) was undertaken among eligible individuals, aged 50 years and above, who were residents of Saki East LGA. A three-stage cluster sampling technique with probability proportional to size was employed to recruit 1100 respondents. Field data were analysed using the RAAB 5 computer software package. Results: The age- and sex-adjusted prevalence of blindness was 1.7% (95% confidence interval: 0.1-3.3). Cataract was the commonest cause of blindness (37.8%) and severe visual impairment (56.3%), whereas refractive error was the leading cause of moderate visual impairment (68.3%). The prevalence of blindness significantly increased with age (χ2= 38.01, P = 0.000). Avoidable conditions were responsible for 94.6% of the blindness. Conclusion: The burden of blindness and visual impairment in the survey area is significant, with more than 90% due to avoidable causes. Cataract, glaucoma, and uncorrected refractive error were important causes needing urgent attention.

Ophthalmic Injuries in Patients with Maxillofacial Trauma Presenting to a Teaching Hospital in North Central Nigeria.

Background: Ophthalmic injuries in patients with maxillofacial trauma are potential causes of a permanent visual loss. These injuries can easily be missed; hence, there is a need for the ophthalmic evaluation of patients with maxillofacial trauma. The main objective of this study was to determine the prevalence, patterns, etiology, and risk factors of ophthalmic injuries in patients presenting with maxillofacial trauma in a teaching hospital in North Central Nigeria. Materials and Methods: The study was a hospital-based, descriptive, cross-sectional study of 67 patients with maxillofacial trauma recruited over a 6-month study period. Information on the sociodemographic and clinical characteristics of the study participants was obtained. The data were analysed using SPSS version 20 statistical software. Pearson's chi-square test was used to test for statistical significance. Results: Ophthalmic involvement was seen in 77.6% of the study participants, with males and individuals aged 21-30 years being more commonly affected. The leading cause of ophthalmic injuries in patients with maxillofacial trauma was road traffic accident (RTA) (75.5%). Others included assaults and fall from heights. Amongst the RTA cases, 71.4% was due to motorcycle-related accident with 91.9% of the patients with ophthalmic injuries observed not to use helmet/seat belt. The use of alcohol and not wearing protective gears were seen as the risk factors. Simple zygomatic complex fracture was the most common trauma observed (44.2%). Conclusion: Ophthalmologic assessment should be conducted for all patients presenting with maxillofacial trauma. The laws on the use of protective gears such as helmets and seat belts should be enforced.

Population-based cross-sectional prevalence survey of diabetes and diabetic retinopathy in Sohag-Egypt, 2019.

OBJECTIVES: To determine the prevalence of diabetes mellitus (DM), prevalence of diabetic retinopathy (DR) and sight-threatening conditions among persons with DM aged 50 years and older in Sohag governorate in Upper Egypt. DESIGN: Population-based, cross-sectional survey using the standardised Rapid Assessment of Avoidable Blindness with the addition of the Diabetic Retinopathy module methodology. SETTINGS: Sohag governorate in Egypt where 68 clusters were selected using probability proportional to population size. Households were selected using the compact segment technique. PARTICIPANTS: 4078 people aged 50 years and older in 68 clusters were enrolled, of which 4033 participants had their random blood sugar checked and 843 examined for features of DR. PRIMARY AND SECONDARY OUTCOMES: The prevalence of DM and DR; secondary outcome was the coverage with diabetic eye care. RESULTS: The prevalence of DM was 20.9% (95% CI 19.3% to 22.5%). The prevalence in females (23.8%; 95% CI 21.4% to 26.3%) was significantly higher than in males (18.9%; 95% CI 17.1% to 20.7%) (p=0.0001). Only 38.8% of persons diagnosed with diabetes had good control of DM. The prevalence of DR in the sample was 17.9% (95% CI 14.7% to 21.1%). The prevalence in females was higher (18.9%; 95% CI 14.0% to 23.8%) than in males (17.1%; 95% CI 13.0% to 21.2%). Up to 85.3% of study participants have never had eye examination. Sight-threatening DR (R4 and/or M2) was detected in 5.2% (95% CI 3.4% to 7.0%) with only 2.3% having had laser treatment. CONCLUSION: The prevalence of uncontrolled DM in Sohag governorate in Egypt is higher than the national prevalence. There is a high prevalence of sight-threatening retinopathy and/or maculopathy with few people having access to diabetic eye care. A public health approach is needed for health promotion, early detection and management of DR.