Analysis of the prevalence and situation of myopia in adolescents from South China

Purpose: To conduct dynamic detection of refraction changes in adolescents with myopia and analyze the correlation between different reexamination times and factors that included age of onset, initial refractive power, and rate of myopia progression. Methods: A total of 900 adolescents (aged 6-15 years) with myopia admitted to Zhongshan Ophthalmic Center between 2009 and 2013 were randomly selected in this investigation. All participants underwent objective refraction measurement with an autorefractometer (Topcon 8900) or streak retinoscopy and subjective refraction detection with an autorefractor (Nidek) or minus-lens procedures at different time intervals (6 months, 1, and 2 years). Accurate refractive power was obtained. All data were analyzed with SPSS 18.0 statistical software. Results: The mean refractive power was increased by 0.56±0.37 diopters (D) after 6 months, by 0.83±0.45 D after 1 year, and by 1.50±0.70D after 2 years. Among the 900 adolescents, the most rapid increase in refractive power was observed at the age of 8 years at the 6-month reexamination, at the age of 8 and 9 years at the 1-year reexamination, and at the age of 7-9 years at the 2-year reexamination. The increase in index of refraction tended to diminish with aging. The different cycles of reexamination revealed a slowing of the rate of myopia progression along with the increase in the initial index of refraction. The highest rate of myopia progression was noted in low-myopic adolescents with initial refractive power ranging from -0.25 to 2.75 D. Conclusion: No positive correlation was documented between different cycles of reexamination and the refractive power. The increase in refractive power was associated with factors that included the reexamination cycle, age of onset, and initial refractive power.