Longitudinal Study of Myopia Progression and Axial Length Growth in Nigerian Children: A Five-Year Cohort in Lagos and Kano

Myopia is a global epidemic with growing prevalence among school-age children, yet longitudinal cohort data on myopia progression and axial length growth in West African children are almost entirely absent. Without such data, evidence-based myopia management interventions cannot be appropriately calibrated for Nigerian children. This study conducts a five-year prospective cohort investigation of myopia progression rates and axial length growth in children aged 7 to 12 years at baseline in Lagos (South West) and Kano (North West). Six hundred myopic children will be recruited from school-based vision screening programs in both cities and followed annually. Key measurements will include cycloplegic autorefraction, axial length by optical biometry, corneal curvature, anterior chamber depth, and crystalline lens power. Multilevel growth curve modeling will characterize progression trajectories and identify risk factors including outdoor time, near work hours, parental myopia, and environmental light exposure. This study will generate the first Nigerian myopia progression norms, providing a critical reference for evaluating myopia control interventions including orthokeratology and low-dose atropine in the West African context. Findings will be disseminated to the Nigerian Optometric Association, school health programs, and global myopia consortia including the International Myopia Institute. Keywords: myopia progression, axial length, Nigerian children, longitudinal cohort, myopia control