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.

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.

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, 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.

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.