Early Myopia Onset, Predicted by First Spectacle Use, is A Risk Factor for High Myopia in Adulthood: A Retrospective Study

Abstract Background: To investigate the risk factors for high myopia in adulthood, especially as it relates to the age of first spectacle wearing. Methods: A retrospective study enrolled adults aged between 20 and 45 years being invited to complete a questionnaire about age, sex, current refractive error, high myopia in parents, age at first spectacle use, refractive power of the first spectacles, and life habits at different educational stages. The association between these factors and high myopia were then evaluated and analyzed. Results: In total, 331 participants were enrolled. Their average refractive error was -4.03 diopters, and high myopia was noted in 27.5% of the study population. Only 3.3% of participants had fathers with high myopia, while 6.0% had mothers with high myopia. The participants received their first spectacles at a mean age of 13.35 years, with a mean refractive error of -1.63 diopters.The significant risk factors for developing high myopia in adult life were earlier age at first spectacle use (p < 0.001), higher refractive power of first spectacles (p < 0.001), mother with high myopia (p = 0.015), and after-school class attendance in senior high school (p = 0.018). Those who wore their first spectacles at < 9 years of age were more predisposed to high myopia than those who did so at ≧ 13 years, with an odds ratio of 24.891, while the odds ratio for those aged between 10 and 12 years was 5.294. Conclusions: The present study shows that earlier age at first spectacle use, higher myopic refraction of first spectacles, mothers with high myopia, and after-school class attendance in senior high school are predictive factors for high myopia in adulthood. The most important predictive factor is earlier age at first spectacle use, which emphasizes earlier myopia control is a protective factor for high myopia in adulthood.