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 (VI) 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 to 49 were recruited via multistage random sampling. Distance visual acuity (VA) was measured unaided, with current correction, and with pinhole using a LogMAR chart at 4 m. 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 REC, eREC and relative 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 VI 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 (p = 0.01, for both). Among those aged 35 or older (n = 1423), adjusted prevalence of uncorrected presbyopia was 30.5% (95% CI: 28.3–32.8%); higher in males and older age groups (45–49 years) (p < 0.05, for both). Distance eREC was 74.1% (95% CI: 71.2–77.0), significantly lower in females (67.7%) than males (79.9%) (p < 0.001), and near eREC was 31.3% (95% CI: 29.8–34.6). The relative quality gap for distance and near was 10.9% and 2.8%, respectively. 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 quality of service. Strengthening near-vision services, enhancing public-private optical partnership, and implementing gender-responsive strategies for service delivery are essential to achieve WHO’s 2030 eREC targets.