Integrating estimation of eye health indicators into trachoma prevalence surveys: a feasibility study in Ethiopia and Nigeria

Abstract

Abstract Background To evaluate the feasibility of generating data for eye health indicators (EHI), including effective refractive error coverage (eREC) and prevalence of vision impairment, in conjunction with trachoma prevalence surveys. Methods All individuals aged ≥6 years participating in trachoma prevalence surveys in two evaluation units (EUs) in each of Nigeria and Ethiopia were invited to participate. In parallel with the routine trachoma survey, a separate team assessed EHI metrics under two visual acuity (VA) measurement protocols. In Nigeria, one EU received the standard VA protocol, while the other received a simplified VA protocol. In Ethiopia, participants were randomised for protocol allocation. Acceptability and feasibility were assessed based on fieldwork cost and time and in-depth interviews with key stakeholders. Findings There were 3806 participants in Nigeria and 4259 in Ethiopia. Prevalence of distance and near vision impairment was 8·4% and 55·3% in Nigeria, and 6·2% and 54·2% in Ethiopia. Distance eREC was 0·0% (95%CI 0·0-0·0) in Nigeria and 1·2% (0·0-3·5) in Ethiopia under the standard protocol, and 0·9% (0·0-2·7) and 9·1% (0·6-17·7) under the simplified protocol. Near eREC was 0·4% (0·0-1·2) (standard) and 1·2% (0·0-2·5) (simplified) in Nigeria, and 2·1% (0·0-4·6) (standard) and 0·9% (0·0-2·1) (simplified) in Ethiopia. The integrated approach was more time- and cost-efficient compared to conducting separate trachoma and EHI surveys. Interviews indicated broad support among stakeholders for the integrated approach. Interpretation There was a large unmet refractive correction need in the participating communities. Integrating EHI measurement into trachoma surveys was acceptable and feasible. Funding Christian Blind Mission, The Carter Center, Sightsavers and Fred Hollows Foundation.