VI, URE and eREC in Koshi Province, Nepal

More than a billion people globally contend with Visual Impairment (VI), which significantly impacts their social, economic, and emotional health. Fortunately, timely interventions can prevent over 75% of vision loss, including treatments like cataract surgery and the use of spectacles, all of which contribute to enhancing the quality of life for individuals affected by vision loss. The primary culprit behind vision impairment is Uncorrected Refractive Errors (URE), making it the foremost cause that can be addressed with appropriate measures.

To determine the prevalence of VI, URE, and effective Refractive Error Coverage (eREC) in Nepal, A population-based Rapid Assessment of Refractive Errors (RARE) survey was conducted in Koshi Province as a pilot study to assess the prevalence of URE, presbyopia and eREC for distance and near. Rapid and quick data collection at low cost, using local resources, and high repeatability at regular intervals to study trends have been the strengths of rapid assessment methods that focus on younger age groups, 15–50 years.

The survey enrolled 4800 participants from 80 clusters in Koshi Province. The study teams visited the selected households and conducted eye examinations. This included monocular unaided (and aided) visual acuity assessment using a Snellen chart with tumbling E optotypes at a distance of 6 meters. Near vision was assessed binocularly using the N notation chart at a fixed distance of 40 cm for each individual. Torchlight examination and distance direct ophthalmoscopy was done. VI was defined as presenting visual acuity worse than 6/12 in the better eye. URE was defined as presenting visual acuity worse than 6/12 and improving to 6/12 or better on using a pinhole. Near Vision Impairment was defined as binocular presenting near vision worse than N8 among those age 35 years and older.

In total, 4057 were examined (84.5% response rate). The prevalence of VI was 3.52% (95% CI:2.89–4.13; n=143). The prevalence of URE in the better eye was 1.95% (95% CI:1.54-2.42; n=79). The Refractive Error Coverage and Effective Refractive Error Coverage were 34.8% and 31.3% respectively. The prevalence of NVI was 34.24% (95% CI: 32.1- 36.40; n=666). The major barriers of not using spectacles were that they were aware of the problem, can manage 43%, no time other priorities 17% and services very far 16.5%.

The prevalence of Visual Impairment and Uncorrected refractive error was low, attributed to the availability and uptake of services in Koshi province in Nepal. This study provides crucial baseline information as plans are made towards achieving the WHO endorsed target of a 40 % increase in effective coverage of refractive error by 2030.