Mapping the Unmet Need for Cataract Surgery Across Local Government Areas in Oyo State Using Spatial Analysis

Geographic disparities in cataract surgical coverage within Nigerian states are poorly quantified at the local government area level, limiting targeted resource allocation and service planning. This study maps the unmet need for cataract surgery across local government areas in Oyo State, South West Nigeria, using spatial analysis methods. A cross-sectional population-based design will be combined with geographic information systems. Rapid assessment of avoidable blindness (RAAB) methodology will be applied in 10 LGAs selected through probability-proportional-to-size sampling, examining 2,500 persons aged 50 years and above. Visual acuity, cataract diagnosis, and prior surgical history will be determined. For each LGA, the cataract surgical coverage, cataract surgical rate, and barriers to surgery will be computed. Spatial autocorrelation analysis and choropleth mapping will identify clustering of high unmet need areas. LGA-level cataract surgical coverage data do not currently exist for Oyo State, limiting the ability of the State Ministry of Health and its partners to direct mobile surgical teams, specialist outreach, and infrastructure investment to the highest-burden areas. RAAB has been validated as the gold standard for rapid blindness prevalence assessment and is endorsed by IAPB for national blindness surveys. This study provides a replicable model for LGA-level ophthalmic needs assessment that can be extended across all Oyo State LGAs and adapted for other states. Recommendations will guide state-level surgical coverage planning and advocate for integration of cataract screening into annual community health surveys. Keywords: cataract surgical coverage, spatial analysis, GIS mapping, Oyo State, RAAB