Ocular biometric parameters and myopia severity in Ghana: A cross-sectional analysis in a young clinical sample

Abstract

ABSTRACT Purpose Myopia prevalence is increasing in sub-Saharan Africa, yet its ocular biometric determinants are not well characterised. This study examined ocular biometric parameters contributing to myopia severity in a Ghanaian sample. Design Observational, clinic-based, cross-sectional study. Participants A total of 406 myopic participants (one eye per participant) aged 8–29 years were recruited from Bishop Ackon Memorial Christian Eye Centre, Cape Coast, Ghana, classified by spherical equivalent (SE) into low, moderate, and high myopia groups per International Myopia Institute criteria. Methods Participants underwent visual acuity testing, autorefraction, slit-lamp biomicroscopy, applanation tonometry, A-scan biometry, optical coherence tomography (retinal nerve fibre layer, cup-to-disc ratio), and specular microscopy (corneal thickness). Between-group differences were assessed using one-way ANOVA, Pearson correlation, and chi-square tests. Biometric contributions to myopia degree were examined using multiple regression. Results Low myopia accounted for 50.5%, moderate for 34.7%, and high myopia for 14.8% of participants; greater severity was associated with older age (χ²(6) = 93.78, P < .001; r = .40). All seven biometric parameters differed significantly across severity groups, with the largest effects for SE, CCT, and AL. In multivariable analysis excluding SE (R² = .744), CCT, RNFL, AL, ACD, and CDR were independent predictors; IOP did not survive correction for multiple comparisons (P = .015). Conclusions Corneal thinning, RNFL reduction, and axial elongation are structural correlates of myopia severity, explaining over 74% of variance and supporting evaluation of biometric assessment for myopia risk stratification.

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