Preventable visual impairment and blindness represent significant global public health challenges. Expanding access to high-volume eye care services in underserved areas may reduce visual impairment and blindness. Visual impairment negatively impacts quality of life, education, and employability, but is often treatable with management following a basic eye examination. Access to basic eyecare in Zambia is limited. Vision Action, a UK-based non-governmental organisation, facilitates eyecare services in Zambia to reduce rectifiable visual impairment by supporting government outreach clinics in underserved communities. This study examines the frequency of presenting visual impairment, uncorrected refractive error, and ocular pathology among outreach clinic attendees in Zambia. A retrospective analysis of outreach clinic records between 2012 and 2015 was performed. The available data include patient demographics, presenting symptoms, presenting level of vision, and classification of any ocular pathology present. Levels of visual impairment were categorised according to the World Health Organization's classification for blindness and visual impairment. Data from 5809 patients were collected (58.5% female, mean age = 41.9 years, SD = 20.7 years). Presenting vision, in the better eye, was classified as ‘moderate visual impairment’ in 14.2% (n = 766), ‘severe visual impairment’ in 0.3% (n = 15) and ‘blind’ in 4.3% (n = 234) of individuals. Uncorrected refractive error was responsible for 62.4% and 57.0% of blindness and severe visual impairment, respectively. Cataract, corneal scarring, and glaucoma were the most common non-refractive ocular pathologies associated with visual impairment. Uncorrected refractive error is the leading cause of blindness and visual impairment in patients presenting to outreach clinics in Zambia and is particularly significant in a predominantly working-age population. Outreach clinics are an effective method of detecting and treating correctable visual impairment in this population. However, there is a need to expand and enhance primary eyecare services to reduce the burden of visual impairment, through management of uncorrected refractive error.

Preventable visual impairment and blindness represent significant global public health challenges. Expanding access to high-volume eye care services in underserved areas may reduce visual impairment and blindness. Visual impairment negatively impacts quality of life, education, and employability, but is often treatable with management following a basic eye examination. Access to basic eyecare in Zambia is limited. Vision Action, a UK-based non-governmental organisation, facilitates eyecare services in Zambia to reduce rectifiable visual impairment by supporting government outreach clinics in underserved communities. This study examines the frequency of presenting visual impairment, uncorrected refractive error, and ocular pathology among outreach clinic attendees in Zambia. A retrospective analysis of outreach clinic records between 2012 and 2015 was performed. The available data include patient demographics, presenting symptoms, presenting level of vision, and classification of any ocular pathology present. Levels of visual impairment were categorised according to the World Health Organization's classification for blindness and visual impairment. Data from 5809 patients were collected (58.5% female, mean age = 41.9 years, SD = 20.7 years). Presenting vision, in the better eye, was classified as ‘moderate visual impairment’ in 14.2% (n = 766), ‘severe visual impairment’ in 0.3% (n = 15) and ‘blind’ in 4.3% (n = 234) of individuals. Uncorrected refractive error was responsible for 62.4% and 57.0% of blindness and severe visual impairment, respectively. Cataract, corneal scarring, and glaucoma were the most common non-refractive ocular pathologies associated with visual impairment. Uncorrected refractive error is the leading cause of blindness and visual impairment in patients presenting to outreach clinics in Zambia and is particularly significant in a predominantly working-age population. Outreach clinics are an effective method of detecting and treating correctable visual impairment in this population. However, there is a need to expand and enhance primary eyecare services to reduce the burden of visual impairment, through management of uncorrected refractive error.

The findings provide greater information on the level of refractive errors in Vietnam, which could assist clinicians and relevant stakeholders to identify high-risk groups and prioritise interventions and preventative measures, contributing to more efficient eye care and cost-effective strategies. Vietnam, a developing country in Southeast Asia, has shown an increase in myopia progression in recent years. However, the prevalence of refractive errors across the country is unclear. The aim of this study was to estimate the pooled prevalence of different refractions in children across Vietnam, and to explore differences between rural and urban areas, and male and female children. A systematic literature search was performed to capture all studies up to April 2024, using online databases including Medline, Web of Science, Scopus, and CINAHL. This was carried out independently by two researchers, following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO ID: CRD42024524780). The quality assessment of included studies was conducted using the Joanna Briggs Institute Prevalence Critical Appraisal Tool checklist. Meta-analysis was performed to estimate pooled refractive error prevalence, with robustness evaluated using 95% confidence intervals and sensitivity analyses. 15 school-based studies were identified (children n = 32,211), of which 6 qualified for meta-analysis inclusion (n = 15,825). The pooled refractive error, myopia, and hyperopia prevalences were calculated respectively as 37.60% [95%CI: 27.78–47.43], 28.83% [95%CI: 19.24–38.42], and 0.41% [95%CI: 0.24–0.59] with high heterogeneities of 99%, p<0.01. Refractive error prevalence was greater in urban locations, and female children. This systematic review and meta-analysis of refractive error prevalence in Vietnamese school children indicates a significant presence of refractive error, especially myopia. However, the large interval ranges suggest that further research using a standardised protocol is required to achieve more accurate estimates.

The findings provide greater information on the level of refractive errors in Vietnam, which could assist clinicians and relevant stakeholders to identify high-risk groups and prioritise interventions and preventative measures, contributing to more efficient eye care and cost-effective strategies. Vietnam, a developing country in Southeast Asia, has shown an increase in myopia progression in recent years. However, the prevalence of refractive errors across the country is unclear. The aim of this study was to estimate the pooled prevalence of different refractions in children across Vietnam, and to explore differences between rural and urban areas, and male and female children. A systematic literature search was performed to capture all studies up to April 2024, using online databases including Medline, Web of Science, Scopus, and CINAHL. This was carried out independently by two researchers, following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (PROSPERO ID: CRD42024524780). The quality assessment of included studies was conducted using the Joanna Briggs Institute Prevalence Critical Appraisal Tool checklist. Meta-analysis was performed to estimate pooled refractive error prevalence, with robustness evaluated using 95% confidence intervals and sensitivity analyses. 15 school-based studies were identified (children n = 32,211), of which 6 qualified for meta-analysis inclusion (n = 15,825). The pooled refractive error, myopia, and hyperopia prevalences were calculated respectively as 37.60% [95%CI: 27.78–47.43], 28.83% [95%CI: 19.24–38.42], and 0.41% [95%CI: 0.24–0.59] with high heterogeneities of 99%, p<0.01. Refractive error prevalence was greater in urban locations, and female children. This systematic review and meta-analysis of refractive error prevalence in Vietnamese school children indicates a significant presence of refractive error, especially myopia. However, the large interval ranges suggest that further research using a standardised protocol is required to achieve more accurate estimates.