Annual Incidences and Progressions of Myopia and High Myopia in Chinese Schoolchildren Based on a 5-Year Cohort Study
This study investigated myopia incidence and progression in Chinese schoolchildren from grade 1 to grade 6. Over a 5-year period, the mean spherical equivalent refraction decreased significantly, with annual myopic shifts, particularly in grades 3 through 6. Myopia prevalence increased substantially, reaching 61.5% in grade 6, and the incidence of high myopia increased from 0.1% to 1.0%. Children with less hyperopic baseline refraction, two myopic parents, longer axial length, and other factors had higher myopia incidence. Girls had a higher cumulative incidence than boys. Hyperopic children showed lower myopia development, suggesting a "hyperopia reserve." The study recommends monitoring hyperopic refraction before primary school to prevent myopia onset, emphasizing interventions before grade 3. The findings contribute to understanding myopia's dynamics in school-aged Chinese children, informing public health strategies to address this global concern.