Myopia Research Lab, Prof. Brien Holden Eye Research Centre & Brien Holden Institute of Optometry and Vision Sceinces, LV Prasad Eye Institute, Hyderabad, India.
Centre for Applied Vision Research, City University of London, London, UK.
BMJ Open Ophthalmol. 2024 May 29;9(1):e001469. doi: 10.1136/bmjophth-2023-001469.
Considering the putative role of light in myopia, and variations in socioeconomic, lifestyle, educational and environmental factors across ethnicities, we objectively investigated light exposure patterns in Indian school children.
The light exposure profile of 143 school children (9-15 years, 50 myopes) recorded using a validated wearable light tracker for six continuous days was analysed. Additional data for non-school days were available for 87 children (26 myopes). The illuminance exposure levels, time spent outdoors and epoch (number of times participant is exposed to a predefined range of lux level per day) were compared between myopes and non-myopes across different light conditions: ≥1000, ≥3000, ≥5000 and ≥10 000 lux. For school days, light exposure profiles during (1) before school, school and after school hours; and (2) class, break and transition (when a student travels to and from school) time were analysed.
The overall median (IQR) daily illuminance exposure level, time spent outdoors and epochs at outdoors (≥1000 lux) were 807 (507-1079) lux/day, 46 (30-64) min/day and 9 (6-12) times/day, respectively. The daily illuminance exposure on non-school days was significantly higher in non-myopes than myopes (6369 (4508-9112) vs 5623 (2616-6929) lux/day, p=0.04). During transition time (school days), non-myopes had significantly higher illuminance exposure (910 (388-1479) vs 550 (263-1098) lux/day, p=0.04), spent more time outdoors (25 (10-43) vs 14 (4-29) min/day, p=0.01) and had higher outdoor epochs (6 (4-11) vs 5 (2-8) times/day, p=0.01) than myopes.
A small but significant difference in illuminance exposure, time spent outdoors and epoch was noted between myopes and non-myopes during transition time, which may have implications in myopia control.
考虑到光在近视中的潜在作用，以及不同种族之间社会经济、生活方式、教育和环境因素的变化，我们客观地研究了印度学童的光照暴露模式。
使用经过验证的可穿戴式光跟踪器连续六天记录了 143 名（9-15 岁，50 名近视）学童的光暴露情况，并对其进行了分析。另外 87 名（26 名近视）非在校儿童的非在校日数据可用。在不同光照条件下（≥1000、≥3000、≥5000 和≥10000 lux），比较了近视和非近视儿童之间的光照暴露水平、户外活动时间和时间（参与者每天暴露在特定范围内的光水平的次数）。对于在校日，分析了（1）上学前、上学中和放学后时段，以及（2）课间、课间休息和课间休息（学生往返学校时）的光照暴露情况。
总的来说，每天的光照暴露水平、户外活动时间和户外活动时间（≥1000 lux）的中位数（IQR）分别为 807（507-1079）lux/天、46（30-64）分钟/天和 9（6-12）次/天。非在校日的非在校日光照暴露水平明显高于近视儿童（6369（4508-9112）比 5623（2616-6929）lux/天，p=0.04）。在课间休息时间（在校日），非近视儿童的光照暴露水平明显较高（910（388-1479）比 550（263-1098）lux/天，p=0.04），户外活动时间更长（25（10-43）比 14（4-29）分钟/天，p=0.01），户外活动时间更多（6（4-11）比 5（2-8）次/天，p=0.01）。
在校日课间休息期间，近视和非近视儿童的光照暴露水平、户外活动时间和时间存在微小但显著的差异，这可能对近视控制有影响。
