Related environmental factors of refractive parameters in children and adolescents aged 6-14

Abstract

Objective: To explore the relationship between environmental factors and refractive parameters of children and adolescents aged 6 to 14 years old. Methods: A total of 566 students aged 6 to 14 years old were selected by using random cluster sampling method in Nankai District and Hongqiao District of Tianjin from September to December 2016. Questionnaires were conducted and refractive parameters were measured including axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD) and lens thickness (LT). Vitreous chamber depth (VCD), corneal radius (CR), the ratio of axial length to corneal radius (AL/CR) and equivalent spherical diopter (SER) were calculated. Multivariate generalized linear model was used to analyze the related factors of refractive parameters. Results: The average age of the subjects was (9.8±2.5) years old, including 302 male students (53.4%). The overall SER, AL, CCT, ACD, LT, VCD, CR and AL/CR ratios were (-1.31±1.85) D, (23.67±1.16) mm, (23.67±1.16) mm, (546.60±31.98) μm, (3.06±0.27) mm, (3.48±0.21) mm, (17.12±1.13) mm, (7.78±0.25) mm and 3.04±0.14, respectively. Multivariate generalized linear model analysis showed that after adjusting for age, gender, height, weight, education level of parents, occupation of parents and family income, compared with those whose daily reading and writing time>6 hours, the AL and VCD of students with daily reading and writing time ≤ 2 hours, 3-4 hours or 5-6 hours were smaller, and the AL/CR ratio of students with daily reading and writing time ≤ 2 hours or 3-4 hours were also smaller (all P<0.05). Compared with those having daily sleep time>9 hours, the students with daily sleep time of 8 hours or 9 hours had higher AL, while the students with daily sleep time of 8 hours had higher CCT, and the students with daily sleep time ≤ 7 hours had higher CR (all P<0.05). Compared with those whose daily electronic screen usage time>1.5 hours, the AL, VCD and CR of students who used electronic screen ≤1.5 hours per day were lower (all P<0.05). Conclusions: Daily reading and writing time, daily electronic screen use time and daily sleep time are the main environmental factors related to eye refractive parameters.