Objective: To study the progression of myopia in school-age children over the past 12 years and factors influencing myopia progression.
Methods: A total of 4569 cases of 5 to 12-year-old children who had refractive examinations in the Third Xiangya Hospital, Central South University between January 2000 and December 2011 were enrolled in this study. The children had no family history of congenital high myopia or other eye diseases. Myopia progression was evaluated when the children were re-examined. The refractive state of each child was measured with cyclopiegic retinoscopy.
Results: The mean spherical equivalent (SE) myopia was-2.0±1.7 D between January 2000 and December 2011. There was no statistical difference in yearly myopia progression between different years. The average age of the myopic children decreased from 10.1 in 2000 to 8.9 years old in 2011 (P<0.05). Mean myopia progression was -0.6±0.7 D per year from 2000 to 2011. Myopia progression reduced gradually in 5 to 8-year-olds (P<0.05), however, it accelerated between ages 9 and 11 years. Myopia progression in 10- and 11-year-olds was significantly greater than in 7- and 8-year-olds (P<0.01). The multiple linear regression analysis demonstrated that age and baseline myopic refraction were positively related to myopia progression.
Conclusions: There was no obvious change in the yearly myopia progression of the children over the past 12 years. The mean age of myopia occurrence became younger with time. More preventive measures are needed to ward off high myopia in children with moderate myopia, especially those aged over 10 years.