Abstract
BACKGROUND: Myopia has shown a sharp upward trend worldwide and has become a global public health concern. However, there were insufficient correction rates all over the world. This study aimed to investigate the prevalence of myopia and spectacle-wearing rate in primary and high school students in Yicheng, as well as analyze the risk factors of myopia onset and development. Additionally, we introduced a novel concept to reflect Relative Visual Acuity Insufficiency (RVAI) in myopia students. METHODS: A school-based cross-sectional study was conducted in 2022, involving 37,908 students in Yicheng. The refractive error was measured using an autorefractor without cycloplegia and recorded as a spherical equivalent refraction (SER). Visual acuity was recorded as uncorrected visual acuity (UCVA). Only worse SER and UCVA values between the two eyes were analyzed. Myopia was defined as SER < -0.50 D and UCVA > 0.2 using the logarithm of the minimum angle of resolution. Multivariance logistic regression identified risk factors for myopia. Correction rate (CR) referred to the proportion of myopic students wearing spectacles. Required Visual Acuity (RVA) and Actual Visual Acuity (AVA) were proposed to calculate the ratio of RVA to AVA (RAR) to assess RVAI. RESULTS: A total of 37,908 primary and high school students were included (16,826 girls, mean age of 11.68 ± 3.04 years). The overall myopia prevalence was 41.6%, with 5.4% classified as high myopia. Older age, girls, and schooling in urban areas were risk factors for myopia. CR increased with grade (13.0% in Grade 1 to 85.8% in Grade 11) but remained low overall (48.2% uncorrected). RAR analysis revealed RVAI of myopia students in Yicheng. CONCLUSIONS: The myopia and high myopia prevalence was high among the students in Yicheng. The proportion of students with uncorrected myopia was high. Further research should be conducted to identify specific socioeconomic factors that contribute to myopia and to lower the incidence of myopia by lowering the exposure to these factors. The RAR metric highlights unmet visual needs even in low and moderate myopia, offering a novel tool for prioritizing interventions. TRIAL REGISTRATION: Not applicable.