[The association between myopic refraction and near work among children and adolescents based on genetic risk score]

Objective: To explore the relationship between myopic refraction and near work in children and adolescents with different genetic risks. Methods: From September to December 2016, Nankai District and Hongqiao District of Tianjin were taken as the study sites. Using the method of stratified cluster random sampling, 533 children and adolescents aged 6-14 years from one primary school and one junior middle school in each of the two districts were included as the study subjects. Refraction measurements by an auto-kerato-refractor and questionnaire survey about near work were conducted. 11 single nucleotide polymorphisms in the selected myopia susceptibility genes were detected, and the genetic risk of each individual was scored. After grouping by genetic risk score, the relationship between myopia and near work was analyzed by the multivariate logistic regression, and the relationship between near work and refraction was analyzed by the multivariate linear regression. Results: The age of 553 subjects was (9.8±2.5) years, including 295 boys (53.3%). The overall detection rate of myopia was 62.0%. The spherical equivalent refraction (SER) was (-1.30±1.85) D. The results of the multivariate logistic regression showed that in the low risk group of GRS, compared with those with continuous near work time less than half an hour, those with continuous near work time no less than half an hour had a higher risk of myopia [OR (95%CI) = 2.64 (1.07, 6.52)]. In the moderate risk group of GRS, the risk of myopia increased with the increase of daily computer use [OR (95%CI) = 2.14 (1.03, 4.77)]. In the high risk group of GRS, the risk of myopia increased with the increase of the total daily reading and writing time [OR (95%CI) = 1.27 (1.01, 1.59)]. The results of the multivariate linear regression showed that in the low risk group of GRS, with increase of 1 hour in the total daily reading and writing time and mobile phone time, the SER decreased by 0.18 D (95%CI:-0.30, -0.07) and 0.95 D (95%CI:-1.51, -0.39), respectively. In the moderate risk group of GRS, with increase of 1 hour in the total daily reading and writing time and computer use time, the SER decreased by 0.25 D (95%CI:-0.31, -0.18) and 0.57 D (95%CI:-0.97, -0.18), respectively. In the high risk group of GRS, with increase of 1 hour in the daily total reading and writing time, the SER decreased by 0.33 D (95%CI:-0.43, -0.22). Conclusion: Continuous near work time no less than half an hour, daily computer use time, the total daily reading and writing time, and daily mobile phone use time were associated with myopic refraction in children and adolescents.