Abstract
Purpose :
The purpose of the current study was to compare the differences of myopia-related behaviors of school children in rural and urban areas.
Methods :
Seventy-eight year-5 students were enrolled for the study, 39 of them from Guangzhou (urban area) and the rest from Ningxiang (rural area). Each was requested to wear a device named ClouclipTM on typical weekdays and typical weekends. ClouclipTM can measure the working distance per 5 seconds and ambient illuminance per 2 minutes accurately. Time for near-work, for too close near-work and for too long near-work was defined as the time during which working distance<70cm, working distance≤30cm and that a single continuous near-work time≥20min, respectively. Data was shown as Mean±SD.
Results :
On the weekday, the mean daily ambient illuminance for students in Guangzhou and Ningxiang was 614.05±178.77lux (range:359.78-1093.35lux) and 918.41±257.81lux (range: 497.09-1690.67lux), respectively. And the mean daily exposure time of ambient illuminance≥1000lux for students in Guangzhou and Ningxiang was 0.69±0.27h (range:0.36-1.21h) and 1.09±0.44h (range:0.45-2.13h), respectively. There were significant differences of the two above metrics between students in Guangzhou and Ningxiang on weekdays (p<0.05). On the weekend, the mean daily ambient illuminance for students in Guangzhou and Ningxiang was 368.85±178.10lux (range:27.25-786.38lux) and 817.87±584.98lux (21.40-2364.37lux), respectively. And the mean daily exposure time of ambient illuminance≥1000lux for students in Guangzhou and Ningxiang was 0.93±0.54h and1.47±1.02h, respectively. Similarly, there were also significant differences of the two above metrics between students in Guangzhou and Ningxiang on weekends(p<0.05). With regards to near-work, there were no differences between students in Guangzhou and Ningxiang in mean daily near-work distance, near-work time, the ratio of too close near-work time / near-work time and the times of too long near-work on weekdays and weekends.
Conclusions :
ClouclipTM provides a new and objective method to quantify myopia-related behaviors. For the students in this study, rural students’ outdoor exposure time and ambient illuminance are higher than urban students, rural students and urban students have no differences in near-work. A prospective and large-scale samples study is needed for further validation.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.