The Impact of Parental Myopia on Myopia in University Students: A Cross-Sectional Study from Shanghai, China

Abstract Background: To evaluate the effect of parental myopia on Chinese university students with a high prevalence of myopia in Shanghai.Methods: A cross-sectional study of university students in Shanghai, China. All participants responded to a detailed questionnaire, including questions about age, ethnicity and family history. They underwent a standardized ophthalmological examination, including visual acuity, a slit lamp examination and non-cycloplegic auto-refraction. Generalized linear model was used to identify risk factors for myopia.Results: Of the 11,977 total subjects, 91.55% were myopic (spherical equivalent refraction [SER] ≤ -0.75 D), 20.18% were highly myopic (SER ≤ -6.0 D) and only 6.94% were emmetropic (-0.75 D＜SER ≤ 0.75 D). The mean age of the myopic participants (19.7±2.4) was higher than that of the emmetropic participants (19.3±1.9, p < 0.001). 10391 (91.8%) of Han students were myopic, which exhibited greater myopia than minority students (91.5%, p < 0.001). Among the students from families with two myopic parents, 97.9% had myopia. Only 93.7% of students had myopia where only one parent was myopic, and among the students without myopic parents, 90.7% had myopia (p < 0.001). Female students whose parents were myopic (8.0%) were more likely to have myopia than male students whose parents were myopic (7.5%) (p < 0.001). Students with two myopic parents (mean difference: -2.04, 95% CI: -2.21, -1.86) were at a high risk of myopia compared with students with no myopic parents (p < 0.001).Conclusions: This study showed that the refractive status of children in a population with a high prevalence of myopia was related to the status of parents. Increased severity of parental myopia led to a greater risk of myopia in their children.