Effective Refractive Error Coverage and Quality Gaps in Bhutan: Evidence from Rapid Assessment of Refractive Error

Background Uncorrected refractive errors (URE) and presbyopia are leading causes of visual impairment globally. Bhutan currently lacks population-based data on adult refractive error, hindering efforts to meet WHO’s 2030 targets for effective refractive error coverage (eREC). Aim To estimate the prevalence of URE, presbyopia, spectacle use, and eREC among individuals aged 18 to 49 years in Bhutan. Methods A population-based cross-sectional survey using the Rapid Assessment of Refractive Error (RARE) methodology was conducted in Bhutan across 61 clusters in 19 districts. Participants aged 18-49 were recruited via multistage random sampling. Distance visual acuity (VA) was measured with unaided, current correction, and pinhole methods using a LogMAR chart at 4 meters. Near VA was assessed at 40 cm with an N notation chart. Prevalence estimates were age- and sex-standardized to the 2017 Bhutan national census data. The eREC and refractive error quality gap were calculated per WHO definitions. Results From a pool of 3,660 eligible participants, 3,523 (96.3%) were examined. The age- and sex-adjusted prevalence of distance visual impairment was 11.0% (95% CI: 10.0-12.0) and refractive error affected 9.95% (95% CI: 8.9-10.98). The adjusted URE prevalence was 2.44% (95% CI: 1.84-3.04), higher in females (p=0.04). Individuals with monastic education (OR: 7.65) and unemployed individuals/housewives (OR: 4.44) had higher URE odds. Among those aged 35 or older (n=1423), presbyopia prevalence was 51.0% (95% CI: 48.3-53.8), significantly higher in males, older age groups (45-49 years), and lower education levels (p>0.05, for all). Distance eREC was 74.1%, lower in females (67.7%) than males (79.9%). Near eREC was 31.3% with a 2.8% quality gap. Spectacle use was 23.5%, higher in females (25.3%, p=0.01). Conclusion URE prevalence in Bhutan is low, but gaps remain in near vision correction, gender equity in eye care access, and service quality. To meet WHO eREC targets, enhancing public-private optical partnerships, integrating presbyopia management into health programs, and adopting gender-sensitive service delivery are imperative. Clinical trial number : Not applicable.