Prevalence and Genetic Risk Profile of Keratoconus Among Young Adults in Ibadan, Oyo State

Keratoconus is a progressive bilateral corneal ectasia that typically manifests in adolescence and early adulthood, causing irregular astigmatism and significant visual impairment. While its genetic underpinnings are increasingly recognized, population-based studies on keratoconus prevalence and genetic risk profiling in Nigeria remain very limited. This study estimates the prevalence of keratoconus and characterizes its genetic risk profile among young adults aged 16 to 35 years in Ibadan, Oyo State, South West Nigeria. A cross-sectional analytical design will be employed, recruiting 800 participants from the University of Ibadan student community and surrounding communities through random cluster sampling. Corneal topography using Placido-based and Scheimpflug imaging will screen for keratoconus and subclinical ectasia. Blood samples will be collected for genetic analysis targeting known susceptibility loci including VSX1, SOD1, and TGFBI. Logistic regression will examine associations between genetic variants, atopy, eye rubbing history, and keratoconus diagnosis. The study anticipates a prevalence of 1 to 3 percent, consistent with recent sub-Saharan African estimates, with significant genetic heterogeneity. Findings will contribute to the corneal genetics literature in Nigeria and provide a reference dataset for contact lens and surgical management decisions. This research advances keratoconus science in the South West zone and supports the establishment of a Nigerian corneal ectasia registry. Keywords: keratoconus, prevalence, genetics, corneal topography, Ibadan